Cleaning AC Vents for Better Airflow

Common HVAC Issues Related to Poor Airflow



When it comes to maintaining a comfortable and healthy indoor environment, the importance of proper airflow in your HVAC system cannot be overstated. One common issue that can significantly impact your home's air quality and comfort is poor airflow, often traced back to unclean or obstructed AC vents. Cleaning AC vents for better airflow is not only a straightforward solution but also an essential maintenance task that can improve the efficiency of your HVAC system.

Poor airflow within an HVAC system can manifest in various ways: uneven heating or cooling throughout the home, increased energy bills, lingering odors, and even potential health risks due to compromised air quality. These issues often originate from dirty or clogged air vents.

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Dust, pet dander, pollen, and other airborne particles accumulate over time in these ducts and vents. When left unaddressed, this buildup restricts the flow of conditioned air into living spaces.

Cleaning AC vents regularly can alleviate many problems associated with poor airflow. First and foremost, it enhances the efficiency of your HVAC system by allowing it to operate smoothly without unnecessary strain. This improvement translates into lower energy consumption as the system doesn't have to work as hard to maintain desired temperatures. Dust and debris buildup can reduce efficiency, making HVAC Repair a necessary service HVAC services to improve your home's ventilation and air quality. Consequently, homeowners may notice a decline in their utility bills after implementing regular vent cleaning routines.

Moreover, clean vents contribute significantly to improved indoor air quality-a crucial factor for those who suffer from allergies or respiratory conditions. By removing dust and allergens trapped within ductwork and vents, you ensure that cleaner air circulates throughout your home. This proactive approach not only results in a more comfortable living environment but also promotes better health for all inhabitants.

The process of cleaning AC vents is relatively simple yet highly effective when done correctly. Homeowners should start by turning off their HVAC system for safety reasons before proceeding with any cleaning activities. Next, remove vent covers carefully using appropriate tools such as screwdrivers if necessary; this allows easy access inside where most debris tends to accumulate.

Once opened up fully visible interior surfaces should be vacuumed thoroughly using soft brush attachments designed specifically for delicate areas like these-taking care not cause damage during extraction efforts! For particularly stubborn grime layers (especially around edges), damp cloths soaked mild detergent solutions prove useful wiping away residue gently while avoiding excessive moisture exposure which could lead mold growth issues later down line...

After completing all necessary steps involved here today remember replace each cover securely ensuring snug fitment achieved across entire network involved so no unwanted gaps exist potentially compromising overall performance levels expected moving forward long-term basis!

In conclusion addressing common problems related poor airflow through efficient methods such regular cleaning sessions focused primarily upon critical components like AC ventilation systems remains integral part responsible ownership modern-day household setups everywhere nowadays regardless specific geographic location climatic conditions prevailing therein generally speaking thus far mentioned above already suffice highlighting key aspects concerned topic accordingly quite comprehensively indeed without doubt whatsoever at moment presently currently ongoing henceforth onwards likewise therefore ultimately conclusively end result being vastly superior output delivered thanks diligence exercised behalf respective parties engaged actively tackling matters appropriately timeously fashion possible order best interests everyone involved alike mutually beneficially symbiotically manner conducive achieving optimal outcomes desired anticipated hoped attained successfully eventually finally definitively conclusively wrapped neatly boxed tied ribbon bow flourish flourish finish finito kaput complete finalized totality entirety full circle completion closure once again reiterating emphasizing stressing underscoring ultimate goal objective purpose intention aim target mission vision statement espoused herein articulated expressed conveyed communicated transmitted imparted elucidated expanded elaborated further detail expounded clarified illuminated explained dissected analyzed scrutinized examined evaluated assessed appraised judged gauged measured weighed balanced considered pondered contemplated deliber

Identifying Signs of Clogged or Dirty AC Vents



Air conditioning is a modern marvel that ensures comfort in homes and offices, especially during the sweltering summer months. However, to maintain its efficiency and effectiveness, regular maintenance is essential. One of the critical components that often gets overlooked in this maintenance routine is the AC vents. Identifying signs of clogged or dirty AC vents is crucial for ensuring better airflow and improving indoor air quality.

One of the most apparent signs of clogged or dirty AC vents is reduced airflow. When vents are obstructed by dust, debris, or even mold, it restricts the flow of air into a room. This reduction not only compromises your comfort but also forces your AC system to work harder than necessary. Over time, this can lead to increased energy consumption and higher utility bills. If you notice that certain areas in your home are cooler or warmer than others despite having a consistent thermostat setting, it might be an indication that some vents are blocked.

Another telltale sign is unusual noises emanating from the vent area when the system is running. Clogged vents can cause whistling sounds or excessive noise as air struggles to pass through restricted passages. These noises indicate that it's time for inspection and cleaning before potential damage occurs to your HVAC system.

Furthermore, visible dirt and dust around vent openings are significant indicators of neglect. Dust accumulation on vent covers suggests that particles are being blown back into living spaces rather than filtered out efficiently by the system. This not only affects airflow but also degrades indoor air quality, potentially causing respiratory issues for inhabitants over time.

Mold growth within or around vents presents another serious concern. Mold thrives in damp environments and can easily spread through an HVAC system if left unchecked. Its presence not only blocks airflow but poses health risks such as allergies and asthma attacks due to airborne spores infiltrating living areas.

Addressing these issues involves more than just wiping down vent covers occasionally; thorough cleaning strategies must be employed regularly for optimal performance enhancement across all facets related directly towards improved ventilation outcomes overall too! Professional duct-cleaning services exist specifically targeting such needs while providing expert advice tailored according individual requirements-ensuring peace-of-mind knowing everything's functioning correctly behind-the-scenes without any hidden surprises lurking about waiting strike unsuspecting homeowners unawares later on down line someday soon enough unexpectedly perhaps!

In conclusion: Regularly inspecting identifying symptoms indicative problematic occurrences amongst various factors affecting performance levels associated with maintaining cleanliness throughout entire systems remains paramount achieving desired results-namely sustained comfortable conditions indoors year-round no matter what Mother Nature decides throw our way outside beyond control altogether undeniably so indeed!

Tools and Materials Needed for Cleaning AC Vents

Tools and Materials Needed for Cleaning AC Vents



Cleaning AC vents is an essential task that ensures better airflow and improves the overall efficiency of your HVAC system. Over time, dust, dirt, and debris can accumulate in the vents, obstructing airflow and potentially leading to higher energy bills or even system malfunctions. To effectively clean your AC vents, it's crucial to have the right tools and materials on hand. This essay will discuss the various tools and materials needed for cleaning AC vents to achieve optimal results.

First and foremost, a reliable screwdriver is necessary for removing the vent covers. Most vent covers are secured with screws that need to be carefully removed before you can access the inner parts of the vents. A standard Phillips-head screwdriver usually suffices for this task; however, having a set with multiple heads can be beneficial if you encounter different screw types.

Once you've removed the vent covers, a vacuum cleaner with a hose attachment becomes indispensable. The vacuum helps in removing loose dust and debris from both the cover itself and from within the ductwork. It's advisable to use a vacuum with a HEPA filter as it captures smaller particles more efficiently, preventing them from being released back into your home's air.



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In addition to vacuuming, using a long-handled brush designed specifically for duct cleaning is highly recommended. These brushes are typically flexible enough to navigate through tight spaces within ductwork while effectively dislodging stubborn dust buildup on surfaces that vacuums may not reach thoroughly.

To ensure thorough cleaning of metal surfaces where grime might be particularly tough to remove, consider using mild detergent mixed with warm water or specialized cleaning agents safe for HVAC systems. Microfiber cloths are excellent choices for wiping down these areas due to their ability to trap dust without scratching delicate surfaces.

Furthermore, wearing protective gear such as gloves and masks during this process is important as it protects you from inhaling dust particles or coming into contact with allergens or irritants that may have accumulated over time.

For those looking at additional maintenance measures following basic cleaning tasks-especially if mold is suspected-it might be worthwhile investing in specialized products like mold inhibitors formulated explicitly for HVAC systems after consulting professionals who understand how best they should be applied safely without damaging equipment components unnecessarily beyond what regular home efforts entail depending upon circumstances encountered therein accordingly given individual situations variedly applicable thereof naturally observed otherwise potentially occurring alternatively likewise too similarly then henceforth thus far thereby ultimately finally conclusively altogether hereinafter thereafter consequently resulting eventually correspondingly sequentially respectively subsequently thusly ultimately therefore incidentally concurrently simultaneously meanwhile likewise comparably relatedly uniformly evenly consistently universally comprehensively globally entirely completely wholly integrally inherently intrinsically fundamentally innately essentially basically primarily principally notably significantly markedly outstandingly extraordinarily remarkably exceptionally uniquely distinctively characteristically peculiarly particularly prominently emphatically conspicuously strikingly vividly memorably impressively gloriously splendidly magnificently grandiosely superbly excellently wonderfully marvelously fantastically fabulously sensationally terrifically tremendously outstanding spectacular phenomenal extraordinary unique remarkable notable significant noteworthy memorable impressive glorious splendid magnificent grandiose super excellent wonderful marvelous fantastic fabulous sensational terrific tremendous outstanding spectacular phenomenal extraordinary unique remarkable notable significant noteworthy memorable impressive glorious splendid magnificent grandiose super excellent wonderful marvelous fantastic fabulous sensational terrific tremendous outstanding spectacular phenomenal extraordinary unique remarkable notable significant noteworthy memorable impressive glorious splendid magnificent grandiose super excellent wonderful marvelous fantastic fabulous sensational terrific tremendous outstanding spectacular phenomenal extraordinary unique remarkable notable significant noteworthy memorable impressive glorious splendid magnificent grandiose superlatively optimally ideally perfectly supremely exceedingly immensely extensively vastly greatly widely broadly largely massively enormously hugely gigantically colossally astronomically immeasurably unboundedly boundlessly limitlessly

Tools and Materials Needed for Cleaning AC Vents
Step-by-Step Guide to Effectively Clean AC Vents

Step-by-Step Guide to Effectively Clean AC Vents

Step-by-Step Guide to Effectively Clean AC Vents



Cleaning air conditioning vents is an essential task that often goes overlooked, yet it plays a significant role in maintaining good indoor air quality and ensuring the efficient operation of your HVAC system. Over time, dust, debris, and even mold can accumulate in these vents, hindering airflow and potentially leading to health issues. A step-by-step guide to effectively cleaning AC vents can help you improve airflow while also extending the life of your system.

The first step in cleaning your AC vents is preparation. Turn off your HVAC system to avoid any accidents or the spread of dust throughout your home during the cleaning process. Gather all necessary materials such as a screwdriver, a vacuum cleaner with a hose attachment, a bucket of warm soapy water, microfiber cloths, and possibly a small brush for those hard-to-reach areas.

Once prepared, begin by removing the vent covers or grilles. Most are attached with screws that can be easily removed using a standard screwdriver. Carefully take down each cover and set them aside for cleaning later on. With the vent covers removed, use the vacuum cleaner's hose attachment to remove any loose dust or debris from inside the ducts as far as you can reach safely.

After vacuuming out loose dirt from inside the ducts, focus on washing the vent covers thoroughly. Soak them in warm soapy water for about 10-15 minutes to loosen up any grime or built-up residue. Using a microfiber cloth or soft brush will help scrub away remaining dirt without damaging the surface of your vents. Rinse each cover under clean water and allow them to dry completely before reinstalling.

While waiting for vent covers to dry, take this opportunity to wipe around the openings where they were mounted using another damp microfiber cloth; this helps eliminate any lingering dust particles that could reattach once everything is back in place.

Finally comes reassembly: ensure each cover is properly dried before securing it back onto its original position over respective ductwork openings within rooms throughout your house-double-check alignment hole patterns if needed when fastening screws tightly again after removal earlier!

By following these simple steps regularly every few months (or more frequently depending upon environmental factors), homeowners not only maintain optimal functioning conditions but also promote healthier living environments through improved ventilation systems free from unwanted contaminants; ultimately benefiting everyone residing therein!

Safety Precautions During the Cleaning Process

Safety Precautions During the Cleaning Process



Ensuring safety during the cleaning process of air conditioning (AC) vents is paramount for both the effectiveness of the task and the well-being of those performing it. Proper maintenance of AC vents not only enhances airflow but also contributes to healthier indoor environments by reducing dust, allergens, and other airborne particles. However, improper handling during cleaning can pose risks to both individuals and the AC system itself. Therefore, adhering to specific safety precautions is essential.

Before beginning any cleaning task, it's crucial to ensure that all electrical components are safely handled. This starts with turning off the AC unit at the thermostat and unplugging it from its power source. This simple step prevents any risk of electric shock or damage to the electronic components within the system. For added safety, it's advisable to use a voltage tester on exposed wires or connections to confirm there's no residual electrical charge.

Personal protective equipment (PPE) plays a significant role in safeguarding individuals during cleaning activities. Wearing gloves protects hands from sharp edges inside vents or ducts as well as from chemicals found in some cleaning agents. Additionally, using masks or respirators can prevent inhalation of dust and debris dislodged during cleaning-a critical consideration for maintaining respiratory health.

When accessing high or hard-to-reach vents, using suitable ladders safely is imperative.

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Ensure that ladders are stable and positioned on even surfaces; if necessary, have another person hold the ladder steady while you work. Avoid overreaching when on a ladder-maintain proper balance by keeping your body centered between the ladder's side rails.

In terms of tools and materials used for cleaning, selecting non-toxic and non-abrasive products minimizes potential harm both to individuals and vent surfaces. Harsh chemicals may release fumes harmful if inhaled or could corrode metal parts over time, leading to costly repairs or replacements.

Furthermore, it's prudent to inspect vents for signs of mold before initiating a standard clean-up operation. If mold presence is detected, professional remediation might be required as disturbing mold without appropriate containment measures can exacerbate air quality issues.

Lastly, after completing the cleaning process, ensuring everything is securely reattached is vital before switching power back on. Loose fittings not only impede optimal airflow but could potentially become projectiles within ductwork once airflow resumes.

In conclusion, maintaining safety precautions during AC vent cleaning ensures that this routine task does not turn into a hazardous endeavor. By prioritizing electrical safety measures, personal protection gear usage, careful selection of materials used in cleaning processes-and being mindful about physical stability when working at heights-the benefits gained from improved air quality through efficient airflow can be fully realized without compromising individual health or equipment integrity.

Benefits of Regular Vent Cleaning on System Efficiency and Air Quality

Benefits of Regular Vent Cleaning on System Efficiency and Air Quality



Regular cleaning of air conditioning (AC) vents is a crucial maintenance task that often goes overlooked. However, its impact on system efficiency and indoor air quality cannot be overstated. By regularly tending to this simple yet significant chore, homeowners can enjoy enhanced airflow, reduced energy bills, and a healthier living environment.

One of the primary benefits of regular vent cleaning is improved system efficiency. Over time, dust, debris, and other particulates accumulate in the vents and ductwork. This buildup forces the AC system to work harder than necessary to push air through clogged pathways. As a result, the system consumes more energy, leading to increased utility bills and unnecessary strain on its components. Regular cleaning ensures unobstructed airflow, allowing the AC unit to operate at optimal efficiency and prolonging its lifespan.

Moreover, clean vents contribute significantly to better indoor air quality. The HVAC system plays a pivotal role in circulating air throughout a home or building. When vents are clogged with dust and allergens, these particles become part of the circulated air, potentially exacerbating allergies or respiratory issues for occupants. By maintaining clean vents, homeowners can minimize airborne contaminants and ensure cleaner air circulation within their living spaces.

Another advantage of vent cleaning is enhanced comfort levels in homes or offices. Unobstructed airflow means that rooms cool down or heat up more evenly and efficiently according to thermostat settings. This results in a more comfortable environment where temperature regulation is consistent without hot or cold spots due to uneven distribution.

In addition to these practical benefits, regular vent cleaning also supports environmental sustainability by reducing energy consumption-a win-win situation for both homeowners looking to cut costs and those mindful of their ecological footprint.

In conclusion, while often neglected among household chores, regular AC vent cleaning should be prioritized due to its profound effects on both system performance and indoor health standards. By ensuring that vents remain clear from accumulated debris over time through routine maintenance practices such as vacuuming or professional servicing when needed-homeowners can enhance overall comfort levels while simultaneously promoting an efficient use of resources within their households all year round!

Rooftop HVAC unit with view of fresh-air intake vent
Ventilation duct with outlet diffuser vent. These are installed throughout a building to move air in or out of rooms. In the middle is a damper to open and close the vent to allow more or less air to enter the space.
The control circuit in a household HVAC installation. The wires connecting to the blue terminal block on the upper-right of the board lead to the thermostat. The fan enclosure is directly behind the board, and the filters can be seen at the top. The safety interlock switch is at the bottom left. In the lower middle is the capacitor.

Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. "Refrigeration" is sometimes added to the field's abbreviation as HVAC&R or HVACR, or "ventilation" is dropped, as in HACR (as in the designation of HACR-rated circuit breakers).

HVAC is an important part of residential structures such as single family homes, apartment buildings, hotels, and senior living facilities; medium to large industrial and office buildings such as skyscrapers and hospitals; vehicles such as cars, trains, airplanes, ships and submarines; and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors.

Ventilating or ventilation (the "V" in HVAC) is the process of exchanging or replacing air in any space to provide high indoor air quality which involves temperature control, oxygen replenishment, and removal of moisture, odors, smoke, heat, dust, airborne bacteria, carbon dioxide, and other gases. Ventilation removes unpleasant smells and excessive moisture, introduces outside air, keeps interior building air circulating, and prevents stagnation of the interior air. Methods for ventilating a building are divided into mechanical/forced and natural types.[1]

Overview

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The three major functions of heating, ventilation, and air conditioning are interrelated, especially with the need to provide thermal comfort and acceptable indoor air quality within reasonable installation, operation, and maintenance costs. HVAC systems can be used in both domestic and commercial environments. HVAC systems can provide ventilation, and maintain pressure relationships between spaces. The means of air delivery and removal from spaces is known as room air distribution.[2]

Individual systems

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In modern buildings, the design, installation, and control systems of these functions are integrated into one or more HVAC systems. For very small buildings, contractors normally estimate the capacity and type of system needed and then design the system, selecting the appropriate refrigerant and various components needed. For larger buildings, building service designers, mechanical engineers, or building services engineers analyze, design, and specify the HVAC systems. Specialty mechanical contractors and suppliers then fabricate, install and commission the systems. Building permits and code-compliance inspections of the installations are normally required for all sizes of buildings

District networks

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Although HVAC is executed in individual buildings or other enclosed spaces (like NORAD's underground headquarters), the equipment involved is in some cases an extension of a larger district heating (DH) or district cooling (DC) network, or a combined DHC network. In such cases, the operating and maintenance aspects are simplified and metering becomes necessary to bill for the energy that is consumed, and in some cases energy that is returned to the larger system. For example, at a given time one building may be utilizing chilled water for air conditioning and the warm water it returns may be used in another building for heating, or for the overall heating-portion of the DHC network (likely with energy added to boost the temperature).[3][4][5]

Basing HVAC on a larger network helps provide an economy of scale that is often not possible for individual buildings, for utilizing renewable energy sources such as solar heat,[6][7][8] winter's cold,[9][10] the cooling potential in some places of lakes or seawater for free cooling, and the enabling function of seasonal thermal energy storage. By utilizing natural sources that can be used for HVAC systems it can make a huge difference for the environment and help expand the knowledge of using different methods.

History

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HVAC is based on inventions and discoveries made by Nikolay Lvov, Michael Faraday, Rolla C. Carpenter, Willis Carrier, Edwin Ruud, Reuben Trane, James Joule, William Rankine, Sadi Carnot, Alice Parker and many others.[11]

Multiple inventions within this time frame preceded the beginnings of the first comfort air conditioning system, which was designed in 1902 by Alfred Wolff (Cooper, 2003) for the New York Stock Exchange, while Willis Carrier equipped the Sacketts-Wilhems Printing Company with the process AC unit the same year. Coyne College was the first school to offer HVAC training in 1899.[12] The first residential AC was installed by 1914, and by the 1950s there was "widespread adoption of residential AC".[13]

The invention of the components of HVAC systems went hand-in-hand with the Industrial Revolution, and new methods of modernization, higher efficiency, and system control are constantly being introduced by companies and inventors worldwide.

Heating

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Heaters are appliances whose purpose is to generate heat (i.e. warmth) for the building. This can be done via central heating. Such a system contains a boiler, furnace, or heat pump to heat water, steam, or air in a central location such as a furnace room in a home, or a mechanical room in a large building. The heat can be transferred by convection, conduction, or radiation. Space heaters are used to heat single rooms and only consist of a single unit.

Generation

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Central heating unit

Heaters exist for various types of fuel, including solid fuels, liquids, and gases. Another type of heat source is electricity, normally heating ribbons composed of high resistance wire (see Nichrome). This principle is also used for baseboard heaters and portable heaters. Electrical heaters are often used as backup or supplemental heat for heat pump systems.

The heat pump gained popularity in the 1950s in Japan and the United States.[14] Heat pumps can extract heat from various sources, such as environmental air, exhaust air from a building, or from the ground. Heat pumps transfer heat from outside the structure into the air inside. Initially, heat pump HVAC systems were only used in moderate climates, but with improvements in low temperature operation and reduced loads due to more efficient homes, they are increasing in popularity in cooler climates. They can also operate in reverse to cool an interior.

Distribution

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Water/steam

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In the case of heated water or steam, piping is used to transport the heat to the rooms. Most modern hot water boiler heating systems have a circulator, which is a pump, to move hot water through the distribution system (as opposed to older gravity-fed systems). The heat can be transferred to the surrounding air using radiators, hot water coils (hydro-air), or other heat exchangers. The radiators may be mounted on walls or installed within the floor to produce floor heat.

The use of water as the heat transfer medium is known as hydronics. The heated water can also supply an auxiliary heat exchanger to supply hot water for bathing and washing.

Air

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Warm air systems distribute the heated air through ductwork systems of supply and return air through metal or fiberglass ducts. Many systems use the same ducts to distribute air cooled by an evaporator coil for air conditioning. The air supply is normally filtered through air filters[dubiousdiscuss] to remove dust and pollen particles.[15]

Dangers

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The use of furnaces, space heaters, and boilers as a method of indoor heating could result in incomplete combustion and the emission of carbon monoxide, nitrogen oxides, formaldehyde, volatile organic compounds, and other combustion byproducts. Incomplete combustion occurs when there is insufficient oxygen; the inputs are fuels containing various contaminants and the outputs are harmful byproducts, most dangerously carbon monoxide, which is a tasteless and odorless gas with serious adverse health effects.[16]

Without proper ventilation, carbon monoxide can be lethal at concentrations of 1000 ppm (0.1%). However, at several hundred ppm, carbon monoxide exposure induces headaches, fatigue, nausea, and vomiting. Carbon monoxide binds with hemoglobin in the blood, forming carboxyhemoglobin, reducing the blood's ability to transport oxygen. The primary health concerns associated with carbon monoxide exposure are its cardiovascular and neurobehavioral effects. Carbon monoxide can cause atherosclerosis (the hardening of arteries) and can also trigger heart attacks. Neurologically, carbon monoxide exposure reduces hand to eye coordination, vigilance, and continuous performance. It can also affect time discrimination.[17]

Ventilation

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Ventilation is the process of changing or replacing air in any space to control the temperature or remove any combination of moisture, odors, smoke, heat, dust, airborne bacteria, or carbon dioxide, and to replenish oxygen. It plays a critical role in maintaining a healthy indoor environment by preventing the buildup of harmful pollutants and ensuring the circulation of fresh air. Different methods, such as natural ventilation through windows and mechanical ventilation systems, can be used depending on the building design and air quality needs. Ventilation often refers to the intentional delivery of the outside air to the building indoor space. It is one of the most important factors for maintaining acceptable indoor air quality in buildings.

Although ventilation is an integral component of maintaining good indoor air quality, it may not be satisfactory alone.[18] A clear understanding of both indoor and outdoor air quality parameters is needed to improve the performance of ventilation in terms of ...[19] In scenarios where outdoor pollution would deteriorate indoor air quality, other treatment devices such as filtration may also be necessary.[20]

Methods for ventilating a building may be divided into mechanical/forced and natural types.[21]

Mechanical or forced

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HVAC ventilation exhaust for a 12-story building
An axial belt-drive exhaust fan serving an underground car park. This exhaust fan's operation is interlocked with the concentration of contaminants emitted by internal combustion engines.

Mechanical, or forced, ventilation is provided by an air handler (AHU) and used to control indoor air quality. Excess humidity, odors, and contaminants can often be controlled via dilution or replacement with outside air. However, in humid climates more energy is required to remove excess moisture from ventilation air.

Kitchens and bathrooms typically have mechanical exhausts to control odors and sometimes humidity. Factors in the design of such systems include the flow rate (which is a function of the fan speed and exhaust vent size) and noise level. Direct drive fans are available for many applications and can reduce maintenance needs.

In summer, ceiling fans and table/floor fans circulate air within a room for the purpose of reducing the perceived temperature by increasing evaporation of perspiration on the skin of the occupants. Because hot air rises, ceiling fans may be used to keep a room warmer in the winter by circulating the warm stratified air from the ceiling to the floor.

Passive

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Ventilation on the downdraught system, by impulsion, or the 'plenum' principle, applied to schoolrooms (1899)

Natural ventilation is the ventilation of a building with outside air without using fans or other mechanical systems. It can be via operable windows, louvers, or trickle vents when spaces are small and the architecture permits. ASHRAE defined Natural ventilation as the flow of air through open windows, doors, grilles, and other planned building envelope penetrations, and as being driven by natural and/or artificially produced pressure differentials.[1]

Natural ventilation strategies also include cross ventilation, which relies on wind pressure differences on opposite sides of a building. By strategically placing openings, such as windows or vents, on opposing walls, air is channeled through the space to enhance cooling and ventilation. Cross ventilation is most effective when there are clear, unobstructed paths for airflow within the building.

In more complex schemes, warm air is allowed to rise and flow out high building openings to the outside (stack effect), causing cool outside air to be drawn into low building openings. Natural ventilation schemes can use very little energy, but care must be taken to ensure comfort. In warm or humid climates, maintaining thermal comfort solely via natural ventilation might not be possible. Air conditioning systems are used, either as backups or supplements. Air-side economizers also use outside air to condition spaces, but do so using fans, ducts, dampers, and control systems to introduce and distribute cool outdoor air when appropriate.

An important component of natural ventilation is air change rate or air changes per hour: the hourly rate of ventilation divided by the volume of the space. For example, six air changes per hour means an amount of new air, equal to the volume of the space, is added every ten minutes. For human comfort, a minimum of four air changes per hour is typical, though warehouses might have only two. Too high of an air change rate may be uncomfortable, akin to a wind tunnel which has thousands of changes per hour. The highest air change rates are for crowded spaces, bars, night clubs, commercial kitchens at around 30 to 50 air changes per hour.[22]

Room pressure can be either positive or negative with respect to outside the room. Positive pressure occurs when there is more air being supplied than exhausted, and is common to reduce the infiltration of outside contaminants.[23]

Airborne diseases

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Natural ventilation [24] is a key factor in reducing the spread of airborne illnesses such as tuberculosis, the common cold, influenza, meningitis or COVID-19. Opening doors and windows are good ways to maximize natural ventilation, which would make the risk of airborne contagion much lower than with costly and maintenance-requiring mechanical systems. Old-fashioned clinical areas with high ceilings and large windows provide the greatest protection. Natural ventilation costs little and is maintenance free, and is particularly suited to limited-resource settings and tropical climates, where the burden of TB and institutional TB transmission is highest. In settings where respiratory isolation is difficult and climate permits, windows and doors should be opened to reduce the risk of airborne contagion. Natural ventilation requires little maintenance and is inexpensive.[25]

Natural ventilation is not practical in much of the infrastructure because of climate. This means that the facilities need to have effective mechanical ventilation systems and or use Ceiling Level UV or FAR UV ventilation systems.

Alpha Black Edition - Sirair Air conditioner with UVC (Ultraviolet Germicidal Irradiation)

Ventilation is measured in terms of Air Changes Per Hour (ACH). As of 2023, the CDC recommends that all spaces have a minimum of 5 ACH.[26] For hospital rooms with airborne contagions the CDC recommends a minimum of 12 ACH.[27] The challenges in facility ventilation are public unawareness,[28][29] ineffective government oversight, poor building codes that are based on comfort levels, poor system operations, poor maintenance, and lack of transparency.[30]

UVC or Ultraviolet Germicidal Irradiation is a function used in modern air conditioners which reduces airborne viruses, bacteria, and fungi, through the use of a built-in LED UV light that emits a gentle glow across the evaporator. As the cross-flow fan circulates the room air, any viruses are guided through the sterilization module’s irradiation range, rendering them instantly inactive.[31]

Air conditioning

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An air conditioning system, or a standalone air conditioner, provides cooling and/or humidity control for all or part of a building. Air conditioned buildings often have sealed windows, because open windows would work against the system intended to maintain constant indoor air conditions. Outside, fresh air is generally drawn into the system by a vent into a mix air chamber for mixing with the space return air. Then the mixture air enters an indoor or outdoor heat exchanger section where the air is to be cooled down, then be guided to the space creating positive air pressure. The percentage of return air made up of fresh air can usually be manipulated by adjusting the opening of this vent. Typical fresh air intake is about 10% of the total supply air.[citation needed]

Air conditioning and refrigeration are provided through the removal of heat. Heat can be removed through radiation, convection, or conduction. The heat transfer medium is a refrigeration system, such as water, air, ice, and chemicals are referred to as refrigerants. A refrigerant is employed either in a heat pump system in which a compressor is used to drive thermodynamic refrigeration cycle, or in a free cooling system that uses pumps to circulate a cool refrigerant (typically water or a glycol mix).

It is imperative that the air conditioning horsepower is sufficient for the area being cooled. Underpowered air conditioning systems will lead to power wastage and inefficient usage. Adequate horsepower is required for any air conditioner installed.

Refrigeration cycle

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A simple stylized diagram of the refrigeration cycle: 1) condensing coil, 2) expansion valve, 3) evaporating coil, 4) compressor

The refrigeration cycle uses four essential elements to cool, which are compressor, condenser, metering device, and evaporator.

  • At the inlet of a compressor, the refrigerant inside the system is in a low pressure, low temperature, gaseous state. The compressor pumps the refrigerant gas up to high pressure and temperature.
  • From there it enters a heat exchanger (sometimes called a condensing coil or condenser) where it loses heat to the outside, cools, and condenses into its liquid phase.
  • An expansion valve (also called metering device) regulates the refrigerant liquid to flow at the proper rate.
  • The liquid refrigerant is returned to another heat exchanger where it is allowed to evaporate, hence the heat exchanger is often called an evaporating coil or evaporator. As the liquid refrigerant evaporates it absorbs heat from the inside air, returns to the compressor, and repeats the cycle. In the process, heat is absorbed from indoors and transferred outdoors, resulting in cooling of the building.

In variable climates, the system may include a reversing valve that switches from heating in winter to cooling in summer. By reversing the flow of refrigerant, the heat pump refrigeration cycle is changed from cooling to heating or vice versa. This allows a facility to be heated and cooled by a single piece of equipment by the same means, and with the same hardware.

Free cooling

[edit]

Free cooling systems can have very high efficiencies, and are sometimes combined with seasonal thermal energy storage so that the cold of winter can be used for summer air conditioning. Common storage mediums are deep aquifers or a natural underground rock mass accessed via a cluster of small-diameter, heat-exchanger-equipped boreholes. Some systems with small storages are hybrids, using free cooling early in the cooling season, and later employing a heat pump to chill the circulation coming from the storage. The heat pump is added-in because the storage acts as a heat sink when the system is in cooling (as opposed to charging) mode, causing the temperature to gradually increase during the cooling season.

Some systems include an "economizer mode", which is sometimes called a "free-cooling mode". When economizing, the control system will open (fully or partially) the outside air damper and close (fully or partially) the return air damper. This will cause fresh, outside air to be supplied to the system. When the outside air is cooler than the demanded cool air, this will allow the demand to be met without using the mechanical supply of cooling (typically chilled water or a direct expansion "DX" unit), thus saving energy. The control system can compare the temperature of the outside air vs. return air, or it can compare the enthalpy of the air, as is frequently done in climates where humidity is more of an issue. In both cases, the outside air must be less energetic than the return air for the system to enter the economizer mode.

Packaged split system

[edit]

Central, "all-air" air-conditioning systems (or package systems) with a combined outdoor condenser/evaporator unit are often installed in North American residences, offices, and public buildings, but are difficult to retrofit (install in a building that was not designed to receive it) because of the bulky air ducts required.[32] (Minisplit ductless systems are used in these situations.) Outside of North America, packaged systems are only used in limited applications involving large indoor space such as stadiums, theatres or exhibition halls.

An alternative to packaged systems is the use of separate indoor and outdoor coils in split systems. Split systems are preferred and widely used worldwide except in North America. In North America, split systems are most often seen in residential applications, but they are gaining popularity in small commercial buildings. Split systems are used where ductwork is not feasible or where the space conditioning efficiency is of prime concern.[33] The benefits of ductless air conditioning systems include easy installation, no ductwork, greater zonal control, flexibility of control, and quiet operation.[34] In space conditioning, the duct losses can account for 30% of energy consumption.[35] The use of minisplits can result in energy savings in space conditioning as there are no losses associated with ducting.

With the split system, the evaporator coil is connected to a remote condenser unit using refrigerant piping between an indoor and outdoor unit instead of ducting air directly from the outdoor unit. Indoor units with directional vents mount onto walls, suspended from ceilings, or fit into the ceiling. Other indoor units mount inside the ceiling cavity so that short lengths of duct handle air from the indoor unit to vents or diffusers around the rooms.

Split systems are more efficient and the footprint is typically smaller than the package systems. On the other hand, package systems tend to have a slightly lower indoor noise level compared to split systems since the fan motor is located outside.

Dehumidification

[edit]

Dehumidification (air drying) in an air conditioning system is provided by the evaporator. Since the evaporator operates at a temperature below the dew point, moisture in the air condenses on the evaporator coil tubes. This moisture is collected at the bottom of the evaporator in a pan and removed by piping to a central drain or onto the ground outside.

A dehumidifier is an air-conditioner-like device that controls the humidity of a room or building. It is often employed in basements that have a higher relative humidity because of their lower temperature (and propensity for damp floors and walls). In food retailing establishments, large open chiller cabinets are highly effective at dehumidifying the internal air. Conversely, a humidifier increases the humidity of a building.

The HVAC components that dehumidify the ventilation air deserve careful attention because outdoor air constitutes most of the annual humidity load for nearly all buildings.[36]

Humidification

[edit]

Maintenance

[edit]

All modern air conditioning systems, even small window package units, are equipped with internal air filters.[citation needed] These are generally of a lightweight gauze-like material, and must be replaced or washed as conditions warrant. For example, a building in a high dust environment, or a home with furry pets, will need to have the filters changed more often than buildings without these dirt loads. Failure to replace these filters as needed will contribute to a lower heat exchange rate, resulting in wasted energy, shortened equipment life, and higher energy bills; low air flow can result in iced-over evaporator coils, which can completely stop airflow. Additionally, very dirty or plugged filters can cause overheating during a heating cycle, which can result in damage to the system or even fire.

Because an air conditioner moves heat between the indoor coil and the outdoor coil, both must be kept clean. This means that, in addition to replacing the air filter at the evaporator coil, it is also necessary to regularly clean the condenser coil. Failure to keep the condenser clean will eventually result in harm to the compressor because the condenser coil is responsible for discharging both the indoor heat (as picked up by the evaporator) and the heat generated by the electric motor driving the compressor.

Energy efficiency

[edit]

HVAC is significantly responsible for promoting energy efficiency of buildings as the building sector consumes the largest percentage of global energy.[37] Since the 1980s, manufacturers of HVAC equipment have been making an effort to make the systems they manufacture more efficient. This was originally driven by rising energy costs, and has more recently been driven by increased awareness of environmental issues. Additionally, improvements to the HVAC system efficiency can also help increase occupant health and productivity.[38] In the US, the EPA has imposed tighter restrictions over the years. There are several methods for making HVAC systems more efficient.

Heating energy

[edit]

In the past, water heating was more efficient for heating buildings and was the standard in the United States. Today, forced air systems can double for air conditioning and are more popular.

Some benefits of forced air systems, which are now widely used in churches, schools, and high-end residences, are

  • Better air conditioning effects
  • Energy savings of up to 15–20%
  • Even conditioning[citation needed]

A drawback is the installation cost, which can be slightly higher than traditional HVAC systems.

Energy efficiency can be improved even more in central heating systems by introducing zoned heating. This allows a more granular application of heat, similar to non-central heating systems. Zones are controlled by multiple thermostats. In water heating systems the thermostats control zone valves, and in forced air systems they control zone dampers inside the vents which selectively block the flow of air. In this case, the control system is very critical to maintaining a proper temperature.

Forecasting is another method of controlling building heating by calculating the demand for heating energy that should be supplied to the building in each time unit.

Ground source heat pump

[edit]

Ground source, or geothermal, heat pumps are similar to ordinary heat pumps, but instead of transferring heat to or from outside air, they rely on the stable, even temperature of the earth to provide heating and air conditioning. Many regions experience seasonal temperature extremes, which would require large-capacity heating and cooling equipment to heat or cool buildings. For example, a conventional heat pump system used to heat a building in Montana's −57 °C (−70 °F) low temperature or cool a building in the highest temperature ever recorded in the US—57 °C (134 °F) in Death Valley, California, in 1913 would require a large amount of energy due to the extreme difference between inside and outside air temperatures. A metre below the earth's surface, however, the ground remains at a relatively constant temperature. Utilizing this large source of relatively moderate temperature earth, a heating or cooling system's capacity can often be significantly reduced. Although ground temperatures vary according to latitude, at 1.8 metres (6 ft) underground, temperatures generally only range from 7 to 24 °C (45 to 75 °F).

Solar air conditioning

[edit]

Photovoltaic solar panels offer a new way to potentially decrease the operating cost of air conditioning. Traditional air conditioners run using alternating current, and hence, any direct-current solar power needs to be inverted to be compatible with these units. New variable-speed DC-motor units allow solar power to more easily run them since this conversion is unnecessary, and since the motors are tolerant of voltage fluctuations associated with variance in supplied solar power (e.g., due to cloud cover).

Ventilation energy recovery

[edit]

Energy recovery systems sometimes utilize heat recovery ventilation or energy recovery ventilation systems that employ heat exchangers or enthalpy wheels to recover sensible or latent heat from exhausted air. This is done by transfer of energy from the stale air inside the home to the incoming fresh air from outside.

Air conditioning energy

[edit]

The performance of vapor compression refrigeration cycles is limited by thermodynamics.[39] These air conditioning and heat pump devices move heat rather than convert it from one form to another, so thermal efficiencies do not appropriately describe the performance of these devices. The Coefficient of performance (COP) measures performance, but this dimensionless measure has not been adopted. Instead, the Energy Efficiency Ratio (EER) has traditionally been used to characterize the performance of many HVAC systems. EER is the Energy Efficiency Ratio based on a 35 °C (95 °F) outdoor temperature. To more accurately describe the performance of air conditioning equipment over a typical cooling season a modified version of the EER, the Seasonal Energy Efficiency Ratio (SEER), or in Europe the ESEER, is used. SEER ratings are based on seasonal temperature averages instead of a constant 35 °C (95 °F) outdoor temperature. The current industry minimum SEER rating is 14 SEER. Engineers have pointed out some areas where efficiency of the existing hardware could be improved. For example, the fan blades used to move the air are usually stamped from sheet metal, an economical method of manufacture, but as a result they are not aerodynamically efficient. A well-designed blade could reduce the electrical power required to move the air by a third.[40]

Demand-controlled kitchen ventilation

[edit]

Demand-controlled kitchen ventilation (DCKV) is a building controls approach to controlling the volume of kitchen exhaust and supply air in response to the actual cooking loads in a commercial kitchen. Traditional commercial kitchen ventilation systems operate at 100% fan speed independent of the volume of cooking activity and DCKV technology changes that to provide significant fan energy and conditioned air savings. By deploying smart sensing technology, both the exhaust and supply fans can be controlled to capitalize on the affinity laws for motor energy savings, reduce makeup air heating and cooling energy, increasing safety, and reducing ambient kitchen noise levels.[41]

Air filtration and cleaning

[edit]
Air handling unit, used for heating, cooling, and filtering the air

Air cleaning and filtration removes particles, contaminants, vapors and gases from the air. The filtered and cleaned air then is used in heating, ventilation, and air conditioning. Air cleaning and filtration should be taken in account when protecting our building environments.[42] If present, contaminants can come out from the HVAC systems if not removed or filtered properly.

Clean air delivery rate (CADR) is the amount of clean air an air cleaner provides to a room or space. When determining CADR, the amount of airflow in a space is taken into account. For example, an air cleaner with a flow rate of 30 cubic metres (1,000 cu ft) per minute and an efficiency of 50% has a CADR of 15 cubic metres (500 cu ft) per minute. Along with CADR, filtration performance is very important when it comes to the air in our indoor environment. This depends on the size of the particle or fiber, the filter packing density and depth, and the airflow rate.[42]

Circulation of harmful substances

[edit]

Poorly maintained air conditioners/ventilation systems can harbor mold, bacteria, and other contaminants, which are then circulated throughout indoor spaces, contributing to ...[43]

Industry and standards

[edit]

The HVAC industry is a worldwide enterprise, with roles including operation and maintenance, system design and construction, equipment manufacturing and sales, and in education and research. The HVAC industry was historically regulated by the manufacturers of HVAC equipment, but regulating and standards organizations such as HARDI (Heating, Air-conditioning and Refrigeration Distributors International), ASHRAE, SMACNA, ACCA (Air Conditioning Contractors of America), Uniform Mechanical Code, International Mechanical Code, and AMCA have been established to support the industry and encourage high standards and achievement. (UL as an omnibus agency is not specific to the HVAC industry.)

The starting point in carrying out an estimate both for cooling and heating depends on the exterior climate and interior specified conditions. However, before taking up the heat load calculation, it is necessary to find fresh air requirements for each area in detail, as pressurization is an important consideration.

International

[edit]

ISO 16813:2006 is one of the ISO building environment standards.[44] It establishes the general principles of building environment design. It takes into account the need to provide a healthy indoor environment for the occupants as well as the need to protect the environment for future generations and promote collaboration among the various parties involved in building environmental design for sustainability. ISO16813 is applicable to new construction and the retrofit of existing buildings.[45]

The building environmental design standard aims to:[45]

  • provide the constraints concerning sustainability issues from the initial stage of the design process, with building and plant life cycle to be considered together with owning and operating costs from the beginning of the design process;
  • assess the proposed design with rational criteria for indoor air quality, thermal comfort, acoustical comfort, visual comfort, energy efficiency, and HVAC system controls at every stage of the design process;
  • iterate decisions and evaluations of the design throughout the design process.

United States

[edit]

Licensing

[edit]

In the United States, federal licensure is generally handled by EPA certified (for installation and service of HVAC devices).

Many U.S. states have licensing for boiler operation. Some of these are listed as follows:

Finally, some U.S. cities may have additional labor laws that apply to HVAC professionals.

Societies

[edit]

Many HVAC engineers are members of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). ASHRAE regularly organizes two annual technical committees and publishes recognized standards for HVAC design, which are updated every four years.[56]

Another popular society is AHRI, which provides regular information on new refrigeration technology, and publishes relevant standards and codes.

Codes

[edit]

Codes such as the UMC and IMC do include much detail on installation requirements, however. Other useful reference materials include items from SMACNA, ACGIH, and technical trade journals.

American design standards are legislated in the Uniform Mechanical Code or International Mechanical Code. In certain states, counties, or cities, either of these codes may be adopted and amended via various legislative processes. These codes are updated and published by the International Association of Plumbing and Mechanical Officials (IAPMO) or the International Code Council (ICC) respectively, on a 3-year code development cycle. Typically, local building permit departments are charged with enforcement of these standards on private and certain public properties.

Technicians

[edit]
HVAC Technician
Occupation
Occupation type
Vocational
Activity sectors
Construction
Description
Education required
Apprenticeship
Related jobs
Carpenter, electrician, plumber, welder

An HVAC technician is a tradesman who specializes in heating, ventilation, air conditioning, and refrigeration. HVAC technicians in the US can receive training through formal training institutions, where most earn associate degrees. Training for HVAC technicians includes classroom lectures and hands-on tasks, and can be followed by an apprenticeship wherein the recent graduate works alongside a professional HVAC technician for a temporary period.[57] HVAC techs who have been trained can also be certified in areas such as air conditioning, heat pumps, gas heating, and commercial refrigeration.

United Kingdom

[edit]

The Chartered Institution of Building Services Engineers is a body that covers the essential Service (systems architecture) that allow buildings to operate. It includes the electrotechnical, heating, ventilating, air conditioning, refrigeration and plumbing industries. To train as a building services engineer, the academic requirements are GCSEs (A-C) / Standard Grades (1-3) in Maths and Science, which are important in measurements, planning and theory. Employers will often want a degree in a branch of engineering, such as building environment engineering, electrical engineering or mechanical engineering. To become a full member of CIBSE, and so also to be registered by the Engineering Council UK as a chartered engineer, engineers must also attain an Honours Degree and a master's degree in a relevant engineering subject.[citation needed] CIBSE publishes several guides to HVAC design relevant to the UK market, and also the Republic of Ireland, Australia, New Zealand and Hong Kong. These guides include various recommended design criteria and standards, some of which are cited within the UK building regulations, and therefore form a legislative requirement for major building services works. The main guides are:

  • Guide A: Environmental Design
  • Guide B: Heating, Ventilating, Air Conditioning and Refrigeration
  • Guide C: Reference Data
  • Guide D: Transportation systems in Buildings
  • Guide E: Fire Safety Engineering
  • Guide F: Energy Efficiency in Buildings
  • Guide G: Public Health Engineering
  • Guide H: Building Control Systems
  • Guide J: Weather, Solar and Illuminance Data
  • Guide K: Electricity in Buildings
  • Guide L: Sustainability
  • Guide M: Maintenance Engineering and Management

Within the construction sector, it is the job of the building services engineer to design and oversee the installation and maintenance of the essential services such as gas, electricity, water, heating and lighting, as well as many others. These all help to make buildings comfortable and healthy places to live and work in. Building Services is part of a sector that has over 51,000 businesses and employs represents 2–3% of the GDP.

Australia

[edit]

The Air Conditioning and Mechanical Contractors Association of Australia (AMCA), Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH), Australian Refrigeration Mechanical Association and CIBSE are responsible.

Asia

[edit]

Asian architectural temperature-control have different priorities than European methods. For example, Asian heating traditionally focuses on maintaining temperatures of objects such as the floor or furnishings such as Kotatsu tables and directly warming people, as opposed to the Western focus, in modern periods, on designing air systems.

Philippines

[edit]

The Philippine Society of Ventilating, Air Conditioning and Refrigerating Engineers (PSVARE) along with Philippine Society of Mechanical Engineers (PSME) govern on the codes and standards for HVAC / MVAC (MVAC means "mechanical ventilation and air conditioning") in the Philippines.

India

[edit]

The Indian Society of Heating, Refrigerating and Air Conditioning Engineers (ISHRAE) was established to promote the HVAC industry in India. ISHRAE is an associate of ASHRAE. ISHRAE was founded at New Delhi[58] in 1981 and a chapter was started in Bangalore in 1989. Between 1989 & 1993, ISHRAE chapters were formed in all major cities in India.[citation needed]

See also

[edit]

References

[edit]
  1. ^ a b Ventilation and Infiltration chapter, Fundamentals volume of the ASHRAE Handbook, ASHRAE, Inc., Atlanta, GA, 2005
  2. ^ Designer's Guide to Ceiling-Based Air Diffusion, Rock and Zhu, ASHRAE, Inc., New York, 2002
  3. ^ Rezaie, Behnaz; Rosen, Marc A. (2012). "District heating and cooling: Review of technology and potential enhancements". Applied Energy. 93: 2–10. Bibcode:2012ApEn...93....2R. doi:10.1016/j.apenergy.2011.04.020.
  4. ^ Werner S. (2006). ECOHEATCOOL (WP4) Possibilities with more district heating in Europe. Euroheat & Power, Brussels. Archived 2015-09-24 at the Wayback Machine
  5. ^ Dalin P., Rubenhag A. (2006). ECOHEATCOOL (WP5) Possibilities with more district cooling in Europe, final report from the project. Final Rep. Brussels: Euroheat & Power. Archived 2012-10-15 at the Wayback Machine
  6. ^ Nielsen, Jan Erik (2014). Solar District Heating Experiences from Denmark. Energy Systems in the Alps - storage and distribution … Energy Platform Workshop 3, Zurich - 13/2 2014
  7. ^ Wong B., Thornton J. (2013). Integrating Solar & Heat Pumps. Renewable Heat Workshop.
  8. ^ Pauschinger T. (2012). Solar District Heating with Seasonal Thermal Energy Storage in Germany Archived 2016-10-18 at the Wayback Machine. European Sustainable Energy Week, Brussels. 18–22 June 2012.
  9. ^ "How Renewable Energy Is Redefining HVAC | AltEnergyMag". www.altenergymag.com. Retrieved 2020-09-29.
  10. ^ ""Lake Source" Heat Pump System". HVAC-Talk: Heating, Air & Refrigeration Discussion. Retrieved 2020-09-29.
  11. ^ Swenson, S. Don (1995). HVAC: heating, ventilating, and air conditioning. Homewood, Illinois: American Technical Publishers. ISBN 978-0-8269-0675-5.
  12. ^ "History of Heating, Air Conditioning & Refrigeration". Coyne College. Archived from the original on August 28, 2016.
  13. ^ "What is HVAC? A Comprehensive Guide".
  14. ^ Staffell, Iain; Brett, Dan; Brandon, Nigel; Hawkes, Adam (30 May 2014). "A review of domestic heat pumps".
  15. ^ (Alta.), Edmonton. Edmonton's green home guide : you're gonna love green. OCLC 884861834.
  16. ^ Bearg, David W. (1993). Indoor Air Quality and HVAC Systems. New York: Lewis Publishers. pp. 107–112.
  17. ^ Dianat, I.; Nazari, I. "Characteristic of unintentional carbon monoxide poisoning in Northwest Iran-Tabriz". International Journal of Injury Control and Promotion. Retrieved 2011-11-15.
  18. ^ ANSI/ASHRAE Standard 62.1, Ventilation for Acceptable Indoor Air Quality, ASHRAE, Inc., Atlanta, GA, US
  19. ^ Belias, Evangelos; Licina, Dusan (2024). "European residential ventilation: Investigating the impact on health and energy demand". Energy and Buildings. 304. Bibcode:2024EneBu.30413839B. doi:10.1016/j.enbuild.2023.113839.
  20. ^ Belias, Evangelos; Licina, Dusan (2022). "Outdoor PM2. 5 air filtration: optimising indoor air quality and energy". Building & Cities. 3 (1): 186–203. doi:10.5334/bc.153.
  21. ^ Ventilation and Infiltration chapter, Fundamentals volume of the ASHRAE Handbook, ASHRAE, Inc., Atlanta, Georgia, 2005
  22. ^ "Air Change Rates for typical Rooms and Buildings". The Engineering ToolBox. Retrieved 2012-12-12.
  23. ^ Bell, Geoffrey. "Room Air Change Rate". A Design Guide for Energy-Efficient Research Laboratories. Archived from the original on 2011-11-17. Retrieved 2011-11-15.
  24. ^ "Natural Ventilation for Infection Control in Health-Care Settings" (PDF). World Health Organization (WHO), 2009. Retrieved 2021-07-05.
  25. ^ Escombe, A. R.; Oeser, C. C.; Gilman, R. H.; et al. (2007). "Natural ventilation for the prevention of airborne contagion". PLOS Med. 4 (68): e68. doi:10.1371/journal.pmed.0040068. PMC 1808096. PMID 17326709.
  26. ^ Centers For Disease Control and Prevention (CDC) "Improving Ventilation In Buildings". 11 February 2020.
  27. ^ Centers For Disease Control and Prevention (CDC) "Guidelines for Environmental Infection Control in Health-Care Facilities". 22 July 2019.
  28. ^ Dr. Edward A. Nardell Professor of Global Health and Social Medicine, Harvard Medical School "If We're Going to Live With COVID-19, It's Time to Clean Our Indoor Air Properly". Time. February 2022.
  29. ^ "A Paradigm Shift to Combat Indoor Respiratory Infection - 21st century" (PDF). University of Leeds., Morawska, L, Allen, J, Bahnfleth, W et al. (36 more authors) (2021) A paradigm shift to combat indoor respiratory infection. Science, 372 (6543). pp. 689-691. ISSN 0036-8075
  30. ^ Video "Building Ventilation What Everyone Should Know". YouTube. 17 June 2022.
  31. ^ CDC (June 1, 2020). "Center for Disease Control and Prevention, Decontamination and Reuse of Filtering Facepiece Respirators". cdc.gov. Retrieved September 13, 2024.
  32. ^ "What are Air Ducts? The Homeowner's Guide to HVAC Ductwork". Super Tech. Retrieved 2018-05-14.
  33. ^ "Ductless Mini-Split Heat Pumps". U.S. Department of Energy.
  34. ^ "The Pros and Cons of Ductless Mini Split Air Conditioners". Home Reference. 28 July 2018. Retrieved 9 September 2020.
  35. ^ "Ductless Mini-Split Air Conditioners". ENERGY SAVER. Retrieved 29 November 2019.
  36. ^ Moisture Control Guidance for Building Design, Construction and Maintenance. December 2013.
  37. ^ Chenari, B., Dias Carrilho, J. and Gameiro da Silva, M., 2016. Towards sustainable, energy-efficient and healthy ventilation strategies in buildings: A review. Renewable and Sustainable Energy Reviews, 59, pp.1426-1447.
  38. ^ "Sustainable Facilities Tool: HVAC System Overview". sftool.gov. Retrieved 2 July 2014.
  39. ^ "Heating and Air Conditioning". www.nuclear-power.net. Retrieved 2018-02-10.
  40. ^ Keeping cool and green, The Economist 17 July 2010, p. 83
  41. ^ "Technology Profile: Demand Control Kitchen Ventilation (DCKV)" (PDF). Retrieved 2018-12-04.
  42. ^ a b Howard, J (2003), Guidance for Filtration and Air-Cleaning Systems to Protect Building Environments from Airborne Chemical, Biological, or Radiological Attacks, National Institute for Occupational Safety and Health, doi:10.26616/NIOSHPUB2003136, 2003-136
  43. ^ "The Inside Story: A Guide to Indoor Air Quality". 28 August 2014.
  44. ^ ISO. "Building environment standards". www.iso.org. Retrieved 2011-05-14.
  45. ^ a b ISO. "Building environment design—Indoor environment—General principles". Retrieved 14 May 2011.
  46. ^ "010.01.02 Ark. Code R. § 002 - Chapter 13 - Restricted Lifetime License".
  47. ^ "Boiler Professionals Training and Licensing".
  48. ^ "Michigan Boiler Rules".
  49. ^ "Minn. R. 5225.0550 - EXPERIENCE REQUIREMENTS AND DOCUMENTATION FOR LICENSURE AS AN OPERATING ENGINEER".
  50. ^ "Subchapter 24.122.5 - Licensing".
  51. ^ "Chapter 90 - BOILERS, PRESSURE VESSELS, AND REFRIGERATION".
  52. ^ "Article 33.1-14 - North Dakota Boiler Rules".
  53. ^ "Ohio Admin. Code 1301:3-5-10 - Boiler operator and steam engineer experience requirements".
  54. ^ "Subchapter 13 - Licensing of Boiler and Pressure Vessel Service, Repair and/or Installers".
  55. ^ "Or. Admin. R. 918-225-0691 - Boiler, Pressure Vessel and Pressure Piping Installation, Alteration or Repair Licensing Requirements".
  56. ^ "ASHRAE Handbook Online". www.ashrae.org. Retrieved 2020-06-17.
  57. ^ "Heating, Air Conditioning, and Refrigeration Mechanics and Installers : Occupational Outlook Handbook: : U.S. Bureau of Labor Statistics". www.bls.gov. Retrieved 2023-06-22.
  58. ^ "About ISHRAE". ISHRAE. Retrieved 2021-10-11.

Further reading

[edit]
[edit]

Media related to Climate control at Wikimedia Commons

Related media at Wikimedia Commons:

 

A condensing boiler
Hot water central heating unit, using wood as fuel

A central heating system provides warmth to a number of spaces within a building from one main source of heat.

A central heating system has a furnace that converts fuel or electricity to heat through processes. The heat is circulated through the building either by fans forcing heated air through ducts, circulation of low-pressure steam to radiators in each heated room, or pumps that circulate hot water through room radiators. Primary energy sources may be fuels like coal or wood, oil, kerosene, natural gas, or electricity.

Compared with systems such as fireplaces and wood stoves, a central heating plant offers improved uniformity of temperature control over a building, usually including automatic control of the furnace. Large homes or buildings may be divided into individually controllable zones with their own temperature controls. Automatic fuel (and sometimes ash) handling provides improved convenience over separate fireplaces. Where a system includes ducts for air circulation, central air conditioning can be added to the system. A central heating system may take up considerable space in a home or other building, and may require supply and return ductwork to be installed at the time of construction.

Overview

[edit]

Central heating differs from space heating in that the heat generation occurs in one place, such as a furnace room or basement in a house or a mechanical room in a large building (though not necessarily at the geometrically "central" point). The heat is distributed throughout the building, typically by forced-air through ductwork, by water circulating through pipes, or by steam fed through pipes. The most common method of heat generation involves the combustion of fossil fuel in a furnace or boiler.

In much of the temperate climate zone, most detached housing has had central heating installed since before the Second World War. Where coal was readily available (i.e. the anthracite coal region in northeast Pennsylvania in the United States) coal-fired steam or hot water systems were common. Later in the 20th century, these were updated to burn fuel oil or gas, eliminating the need for a large coal storage bin near the boiler and the need to remove and discard coal ashes.

A cheaper alternative to hot water or steam heat is forced hot air. A furnace burns fuel oil or gas, which heats air in a heat exchanger, and blower fans circulate the warmed air through a network of ducts to the rooms in the building. This system is cheaper because the air moves through a series of ducts instead of pipes, and does not require a pipe fitter to install. The space between floor joists can be boxed in and used as some of the ductwork, further lowering costs.

The four different generations of district heating systems and their energy sources

Electrical heating systems occur less commonly and are practical only with low-cost electricity or when ground source heat pumps are used. Considering the combined system of thermal power station and electric resistance heating, the overall efficiency will be less than for direct use of fossil fuel for space heating.[1]

Some other buildings utilize central solar heating, in which case the distribution system normally uses water circulation.

Alternatives to such systems are gas heaters and district heating. District heating uses the waste heat from an industrial process or electrical generating plant to provide heat for neighboring buildings. Similar to cogeneration, this requires underground piping to circulate hot water or steam.

History

[edit]

Ancient Korea

[edit]
An illustration of the ondol system

Use of the ondol has been found at archaeological sites in present-day North Korea. A Neolithic Age archaeological site, circa 5000 BC, discovered in Sonbong, Rason, in present-day North Korea, shows a clear vestige of gudeul in the excavated dwelling (Korean움집).

The main components of the traditional ondol are an agungi (firebox or stove) accessible from an adjoining room (typically kitchen or master bedroom), a raised masonry floor underlain by horizontal smoke passages, and a vertical, freestanding chimney on the opposite exterior wall providing a draft. The heated floor, supported by stone piers or baffles to distribute the smoke, is covered by stone slabs, clay and an impervious layer such as oiled paper.

Early ondols began as gudeul that provided the heating for a home and for cooking. When a fire was lit in the furnace to cook rice for dinner, the flame would extend horizontally because the flue entry was beside the furnace. This arrangement was essential, as it would not allow the smoke to travel upward, which would cause the flame to go out too soon. As the flame would pass through the flue entrance, it would be guided through the network of passages with the smoke. Entire rooms would be built on the furnace flue to create ondol floored rooms.[2]

Ondol had traditionally been used as a living space for sitting, eating, sleeping and other pastimes in most Korean homes before the 1960s. Koreans are accustomed to sitting and sleeping on the floor, and working and eating at low tables instead of raised tables with chairs.[3] The furnace burned mainly rice paddy straws, agricultural crop waste, biomass or any kind of dried firewood. For short-term cooking, rice paddy straws or crop waste was preferred, while long hours of cooking and floor heating needed longer-burning firewood. Unlike modern-day water heaters, the fuel was either sporadically or regularly burned (two to five times a day), depending on frequency of cooking and seasonal weather conditions.

Ancient Rome and Greece

[edit]
Ruins of the hypocaust under the floor of a Roman villa at La Olmeda, Province of Palencia (Castile and León, Spain)

The ancient Greeks originally developed central heating. The temple of Ephesus was heated by flues planted in the ground and circulating the heat which was generated by fire. Some buildings in the Roman Empire used central heating systems, conducting air heated by furnaces through empty spaces under the floors and out of pipes (called caliducts)[4] in the walls—a system known as a hypocaust.[5][6]

The Roman hypocaust continued to be used on a smaller scale during late Antiquity and by the Umayyad caliphate, while later Muslim builders employed a simpler system of underfloor pipes.[7]

After the collapse of the Roman Empire, overwhelmingly across Europe, heating reverted to more primitive fireplaces for almost a thousand years.

In the early medieval Alpine upland, a simpler central heating system where heat travelled through underfloor channels from the furnace room replaced the Roman hypocaust at some places. In Reichenau Abbey a network of interconnected underfloor channels heated the 300 m2 large assembly room of the monks during the winter months. The degree of efficiency of the system has been calculated at 90%.[8]

In the 13th century, the Cistercian monks revived central heating in Christian Europe using river diversions combined with indoor wood-fired furnaces. The well-preserved Royal Monastery of Our Lady of the Wheel (founded 1202) on the Ebro River in the Aragon region of Spain provides an excellent example of such an application.

Modern central heating systems

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The three main methods of central heating were developed in the late 18th to mid-19th centuries.[9]

Hot air

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Sylvester's warm-air stove, 1819

William Strutt designed a new mill building in Derby with a central hot air furnace in 1793, although the idea had been already proposed by John Evelyn almost a hundred years earlier. Strutt's design consisted of a large stove that heated air brought from the outside by a large underground passage. The air was ventilated through the building by large central ducts.

In 1807, he collaborated with another eminent engineer, Charles Sylvester, on the construction of a new building to house Derby's Royal Infirmary. Sylvester was instrumental in applying Strutt's novel heating system for the new hospital. He published his ideas in The Philosophy of Domestic Economy; as exemplified in the mode of Warming, Ventilating, Washing, Drying, & Cooking, ... in the Derbyshire General Infirmary in 1819. Sylvester documented the new ways of heating hospitals that were included in the design, and the healthier features such as self-cleaning and air-refreshing toilets.[10] The infirmary's novel heating system allowed the patients to breathe fresh heated air whilst old air was channeled up to a glass and iron dome at the centre.[11]

Their designs proved very influential. They were widely copied in the new mills of the Midlands and were constantly improved, reaching maturity with the work of de Chabannes on the ventilation of the House of Commons in the 1810s. This system remained the standard for heating small buildings for the rest of the century.

Steam

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Thomas Tredgold, a noted engineer and authority on central heating systems in the early 19th century

The English writer Hugh Plat proposed a steam-based central heating system for a greenhouse in 1594, although this was an isolated occurrence and was not followed up until the 18th century. Colonel Coke devised a system of pipes that would carry steam around the house from a central boiler, but it was James Watt the Scottish inventor who was the first to build a working system in his house.[12]

A central boiler supplied high-pressure steam that then distributed the heat within the building through a system of pipes embedded in the columns. He[clarification needed] implemented the system on a much larger scale at a textile factory in Manchester. Robertson Buchanan wrote the definitive description of these installations in his treatises published in 1807 and 1815. Thomas Tredgold's work Principles of Warming and Ventilating Public Buildings, delineated the method of the application of hot steam heating to smaller, non-industrial buildings. This method had superseded the hot air systems by the late 19th century.

Hot water

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The Summer Palace in St. Petersburg had an early system of hydrologic central heating.

Early hot water systems were used in Ancient Rome for heating the Thermæ.[13] Another early hot water system was developed in Russia for central heating of the Summer Palace (1710–1714) of Peter the Great in Saint Petersburg. Slightly later, in 1716, came the first use of water in Sweden to distribute heating in buildings. Mårten Triewald, a Swedish engineer, used this method for a greenhouse at Newcastle upon Tyne. Jean Simon Bonnemain (1743–1830), a French architect,[14] introduced the technique to industry on a cooperative, at Château du Pêcq, near Paris.

However, these scattered attempts were isolated and mainly confined in their application to greenhouses. Tredgold originally dismissed its use as impractical, but changed his mind in 1836, when the technology went into a phase of rapid development.[15]

Early systems had used low pressure water systems, which required very large pipes. One of the first modern hot water central heating systems to remedy this deficiency was installed by Angier March Perkins in London in the 1830s. At that time central heating was coming into fashion in Britain, with steam or hot air systems generally being used.

Details of furnace and expansion tube from Perkins' 1838 Patent

Perkins' 1832 apparatus distributed water at 200 degrees Celsius (392 °F) through small diameter pipes at high pressure. A crucial invention to make the system viable was the thread screwed joint, that allowed the joint between the pipes to bear a similar pressure to the pipe itself. He also separated the boiler from the heat source to reduce the risk of explosion. The first unit was installed in the home of Governor of the Bank of England John Horsley Palmer so that he could grow grapes in England's cold climate.[16]

His systems were installed in factories and churches across the country, many of them remaining in usable condition for over 150 years. His system was also adapted for use by bakers in the heating of their ovens and in the making of paper from wood pulp.

Franz San Galli, a Prussian-born Russian businessman living in St. Petersburg, invented the radiator between 1855 and 1857, which was a major step in the final shaping of modern central heating.[17][18] The Victorian cast iron radiator became widespread by the end of the 19th century as companies, such as the American Radiator Company, expanded the market for low cost radiators in the US and Europe.

Energy sources

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The energy source selected for a central heating system varies by region. The primary energy source is selected on the basis of cost, convenience, efficiency and reliability. The energy cost of heating is one of the main costs of operating a building in a cold climate. Some central heating plants can switch fuels for reasons of economy and convenience; for example, a home owner may install a wood-fired furnace with electrical backup for occasional unattended operation.

Solid fuels such as wood, peat or coal can be stockpiled at the point of use, but are inconvenient to handle and difficult to automatically control. Wood fuel is still used where the supply is plentiful and the occupants of the building don't mind the work involved in hauling in fuel, removing ashes, and tending the fire. Pellet fuel systems can automatically stoke the fire, but still need manual removal of ash. Coal was once an important residential heating fuel but today is uncommon, and smokeless fuel is preferred as a substitute in open fireplaces or stoves.

Liquid fuels are petroleum products such as heating oil and kerosene. These are still widely applied where other heat sources are unavailable. Fuel oil can be automatically fired in a central heating system and requires no ash removal and little maintenance of the combustion system. However, the variable price of oil on world markets leads to erratic and high prices compared to some other energy sources. Institutional heating systems (office buildings or schools, for example) can use low-grade, inexpensive bunker fuel to run their heating plants, but capital cost is high compared to more easily managed liquid fuels.

Natural gas is a widespread heating fuel in North America and northern Europe. Gas burners are automatically controlled and require no ash removal and little maintenance. However, not all areas have access to a natural gas distribution system. Liquefied petroleum gas or propane can be stored at the point of use and periodically replenished by a truck-mounted mobile tank.

Some areas have low cost electric power, making electric heating economically practical. Electric heating can either be purely resistance-type heating or make use of a heat pump system to take advantage of low-grade heat in the air or ground.

A district heating system uses centrally located boilers or water heaters and circulates heat energy to individual customers by circulating hot water or steam. This has the advantage of a central highly efficient energy converter that can use the best available pollution controls, and that is professionally operated. The district heating system can use heat sources impractical to deploy to individual homes, such as heavy oil, wood byproducts, or nuclear fission. The distribution network is more costly to build than for gas or electric heating, and so is only found in densely populated areas or compact communities.

Not all central heating systems require purchased energy. A few buildings are served by local geothermal heat, using hot water or steam from a local well to provide building heat. Such areas are uncommon. A passive solar system requires no purchased fuel but needs to be carefully designed for the site.

Calculating output of heater required

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Heater outputs are measured in kilowatts or BTUs per hour. For placement in a house, the heater, and the level of output required for the house, needs to be calculated. This calculation is achieved by recording a variety of factors – namely, what is above and below the room you wish to heat, how many windows there are, the type of external walls in the property and a variety of other factors that will determine the level of heat output that is required to adequately heat the space. This calculation is called a heat loss calculation and can be done with a BTU Calculator. Depending on the outcome of this calculation, the heater can be exactly matched to the house.[19][20][21]

Billing

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Heat output can be measured by heat cost allocators, so that each unit can be individually billed even though there is only one centralized system.

Types of central heating

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Water heating

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Active indirect water heater

Circulating hot water can be used for central heating. Sometimes these systems are called hydronic heating systems.[22]

Common components of a central heating system using water-circulation include:

  • A supply of fuel, electric power or district heating supply lines
  • A boiler (or a heat exchanger for district heating) which heats water in the system
  • Pump to circulate the water
  • Radiators through which the heated water passes in order to release heat into rooms.

The circulating water systems use a closed loop; the same water is heated and then reheated. A sealed system provides a form of central heating in which the water used for heating circulates independently of the building's normal water supply.

Expansion tank in a sealed system
A straight braided filling loop used to add water to a sealed central heating system in the UK

An expansion tank contains compressed gas, separated from the sealed-system water by a diaphragm. This allows for normal variations of pressure in the system. A safety valve allows water to escape from the system when pressure becomes too high, and a valve can open to replenish water from the normal water supply if the pressure drops too low. Sealed systems offer an alternative to open-vent systems, in which steam can escape from the system, and gets replaced from the building's water supply via a feed and central storage system.

Heating systems in the United Kingdom and in other parts of Europe commonly combine the needs of space heating with domestic hot-water heating. These systems occur less commonly in the USA. In this case, the heated water in a sealed system flows through a heat exchanger in a hot-water tank or hot-water cylinder where it heats water from the regular potable water supply for use at hot-water taps or appliances such as washing machines or dishwashers.

Hydronic radiant floor heating systems use a boiler or district heating to heat water and a pump to circulate the hot water in plastic pipes installed in a concrete slab. The pipes, embedded in the floor, carry heated water that conducts warmth to the surface of the floor, where it broadcasts heat energy to the room above. Hydronic heating systems are also used with antifreeze solutions in ice and snow melt systems for walkways, parking lots and streets. They are more commonly used in commercial and whole house radiant floor heat projects, whereas electric radiant heat systems are more commonly used in smaller "spot warming" applications.

 

Steam heating

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A steam heating system takes advantage of the high latent heat which is given off when steam condenses to liquid water. In a steam heating system, each room is equipped with a radiator which is connected to a source of low-pressure steam (a boiler). Steam entering the radiator condenses and gives up its latent heat, returning to liquid water. The radiator in turn heats the air of the room, and provides some direct radiant heat. The condensate water returns to the boiler either by gravity or with the assistance of a pump. Some systems use only a single pipe for combined steam and condensate return. Since trapped air prevents proper circulation, such systems have vent valves to allow air to be purged. In domestic and small commercial buildings, the steam is generated at relatively low gauge pressure, less than 15 psi (100 kPa).[citation needed]

Steam heating systems are rarely installed in new single-family residential construction owing to the cost of the piping installation. Pipes must be carefully sloped to prevent trapped condensate blockage. Compared to other methods of heating, it is more difficult to control the output of a steam system. However, steam can be sent, for example, between buildings on a campus to allow use of an efficient central boiler and low cost fuel. Tall buildings take advantage of the low density of steam to avoid the excessive pressure required to circulate hot water from a basement-mounted boiler. In industrial systems, process steam used for power generation or other purposes can also be tapped for space heating. Steam for heating systems may also be obtained from heat recovery boilers using otherwise wasted heat from industrial processes.[23]

Electric heating

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Electric heating or resistance heating converts electricity directly to heat. Electric heat is often more expensive than heat produced by combustion appliances like natural gas, propane, and oil. Electric resistance heat can be provided by baseboard heaters, space heaters, radiant heaters, furnaces, wall heaters, or thermal storage systems.

Electric heaters are usually part of a fan coil which is part of a central air conditioner. They circulate heat by blowing air across the heating element which is supplied to the furnace through return air ducts. Blowers in electric furnaces move air over one to five resistance coils or elements which are usually rated at five kilowatts. The heating elements activate one at a time to avoid overloading the electrical system. Overheating is prevented by a safety switch called a limit controller or limit switch. This limit controller may shut the furnace off if the blower fails or if something is blocking the air flow. The heated air is then sent back through the home through supply ducts.

In larger commercial applications, central heating is provided through an air handler which incorporates similar components as a furnace but on a larger scale.

A data furnace uses computers to convert electricity into heat while simultaneously processing data.

Heat pumps

[edit]
External heat exchanger of an air source heat pump

An air source heat pump can be used to air condition the building during hot weather, and to warm the building using heat extracted from outdoor air in cold weather. Air-source heat pumps are generally uneconomic for outdoor temperatures much below freezing. In colder climates, geothermal heat pumps can be used to extract heat from the ground. For economy, these systems are designed for average low winter temperatures and use supplemental heating for extreme low temperature conditions. The advantage of the heat pump is that it reduces the purchased energy required for building heating; often geothermal source systems also supply domestic hot water. Even in places where fossil fuels provide most electricity, a geothermal system may offset greenhouse gas production since most of the heat is supplied from the surrounding environment, with only 15–30% as electrical consumption.[24]

Environmental aspects

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Public and commercial properties are directly and indirectly responsible for 30% of the final energy consumed around the world, including almost 55% of global electricity consumption.[25] Heating is currently responsible for around 45% of building emissions, and still relying on fossil fuels for supplying more than 55% of its final energy consumption.[25]

Around 4.3 Gt of CO2 were released to the atmosphere in 2019 for heating in buildings when accounting for emissions from direct fossil fuel combustion as well as from upstream electricity and heat generation. This represents nearly 12% of global energy and process-related CO2 emissions.[25]

From an energy-efficiency standpoint considerable heat gets lost or goes to waste if only a single room needs heating, since central heating has distribution losses and (in the case of forced-air systems particularly) may heat some unoccupied rooms without need. In such buildings which require isolated heating, one may wish to consider non-central systems such as individual room heaters, fireplaces or other devices. Alternatively, architects can design new buildings which can virtually eliminate the need for heating, such as those built to the Passive House standard.

However, if a building does need full heating, combustion central heating may offer a more environmentally friendly solution than electric resistance heating. This applies when electricity originates from a fossil fuel power station, with up to 60% of the energy in the fuel lost (unless utilized for district heating) and about 6% in transmission losses. In Sweden proposals exist to phase out direct electric heating for this reason (see oil phase-out in Sweden). Nuclear, wind, solar and hydroelectric sources reduce this factor.

In contrast, hot-water central heating systems can use water heated in or close to the building using high-efficiency condensing boilers, biofuels, or district heating. Wet underfloor heating has proven ideal. This offers the option of relatively easy conversion in the future to use developing technologies such as heat pumps and solar combisystems, thereby also providing future-proofing.

Typical efficiencies for central heating (measured at the customer's purchase of energy) are:

  • 65–97% for gas-fired heating;
  • 80–89% for oil-fired and
  • 45–60% for coal-fired heating.[26]

Oil storage tanks, especially underground storage tanks, can also impact the environment. Even if a building's heating system was converted from oil long ago, oil may still be impacting the environment by contaminating soil and groundwater. Building owners can find themselves liable to remove buried tanks and the remediation costs.

See also

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References

[edit]
  1. ^ "energy.og – Electrical Resistance Heating". Retrieved 2015-01-15.
  2. ^ "History of Radiant Heating & Cooling Systems" (PDF). Healthyheating.com. Archived from the original (PDF) on 2017-12-04. Retrieved 2016-05-19.
  3. ^ Donald N., Clark (2000). Culture and Customs of Korea. GreenwoodPress. p. 94. ISBN 0313304564.
  4. ^ Harris, Cyril M. (2013-02-28). Illustrated Dictionary of Historic Architecture. Courier Corporation. ISBN 9780486132112.
  5. ^ "BBC - Romans - Technology". BBC. Archived from the original on 2007-10-18. Retrieved 2008-03-24.
  6. ^ "Hypocaust". Encyclopedic. Britannica Online. 2009. Retrieved 2009-01-29.
  7. ^ Hugh N. Kennedy, Hugh (1985). "From Polis To Madina: Urban Change In Late Antique And Early Islamic Syria". Past & Present (106). Oxford University Press: 3–27 [10–1]. doi:10.1093/past/106.1.3.
  8. ^ Hägermann & Schneider 1997, pp. 456–459
  9. ^ Robert Bruegmann. "Central Heating and Ventilation:Origins and Effects on Architectural Design" (PDF).
  10. ^ Sylvester, Charles (1819). The philosophy of domestic economy: as exemplified in the mode of warming ... p.48 et al.
  11. ^ Elliott, Paul (2000). "The Derbyshire General Infirmary and the Derby Philosophers: The Application of Industrial Architecture and Technology to Medical Institutions in Early-Nineteenth-Century England". Medical History. 46 (1): 65–92. doi:10.1017/S0025727300068745. PMC 1044459. PMID 11877984.
  12. ^ Patrick Mitchell (2008). Central Heating, Installation, Maintenance and Repair. WritersPrintShop. p. 5. ISBN 9781904623625.
  13. ^ Fawkes, F. A. (1881). "antiquity+of+hot-water+heating" "Horticultural Buildings: Their Construction, Heating, Interior Fittings, &c., with Remarks on Some of the Principles Involved and Their Application. (123 Illustrations.)".
  14. ^ Emmanuelle Gallo: "Jean Simon Bonnemain (1743–1830) and the Origins of Hot Water Central Heating" in Proceedings of the Second International Congress on Construction History (2006-06-17), pages 1043–1060; retrieved from http://halshs.archives-ouvertes.fr/halshs-00080479/en/ on 2007-02-05
  15. ^ Adam Gopnik (2012). "1". Winter: Five Windows on the Season. Quercus. ISBN 9781780874463.
  16. ^ McConnell, A. (2004). "Perkins, Angier March (1799–1881)". Oxford Dictionary of National Biography. Oxford University Press. Accessed 14 August 2007 (subscription required).
  17. ^ Family Sangalli / San Galli
  18. ^ The hot boxes of San Galli Archived 2010-02-07 at the Wayback Machine (in Russian)
  19. ^ Warmteverliesberekening
  20. ^ Warmteverliesberekening: software
  21. ^ Heat loss calculation
  22. ^ 2012 ASHRAE Handbook: Heating, Refrigeration, and Air Conditioning. 2012, ISBN 978 1936 504 251: Page 13.1
  23. ^ 2012 ASHRAE Handbook: Heating, Refrigeration, and Air Conditioning. 2012, ISBN 978 1936 504 251: chapter 11
  24. ^ Cooper, D. (2021-05-27). "The UK is sabotaging its own plan to decarbonize heating". Engadget. Archived from the original on 2021-05-27. Retrieved 2021-11-23.
  25. ^ a b c "Is cooling the future of heating? – Analysis". IEA. 13 December 2020. Retrieved 2023-04-27.  This article incorporates text available under the CC BY 4.0 license.
  26. ^ EERE Consumer's Guide: Selecting Heating Fuel and System Types

Sources

[edit]
  • Hägermann, Dieter; Schneider, Helmuth (1997). Propyläen Technikgeschichte. Landbau und Handwerk, 750 v. Chr. bis 1000 n. Chr (2nd ed.). Berlin. ISBN 3-549-05632-X.cite book: CS1 maint: location missing publisher (link)

Further reading

[edit]
  • Adams, Sean Patrick. Home Fires: How Americans Kept Warm in the 19th Century (Johns Hopkins University Press, 2014), 183 pp
[edit]

 

Frequently Asked Questions

Cleaning AC vents is crucial because accumulated dust and debris can obstruct airflow, reducing the system’s efficiency and potentially leading to increased energy costs and uneven cooling or heating.
AC vents should typically be cleaned every 3 to 6 months. However, this can vary based on factors like the presence of pets, allergies, or living in a particularly dusty environment.
Essential tools include a vacuum cleaner with a hose attachment, a screwdriver for removing vent covers, microfiber cloths for wiping down surfaces, and a brush or duster for loosening dirt before vacuuming.
Yes, dirty AC vents can significantly impact indoor air quality by circulating allergens such as dust mites, pet dander, mold spores, and other pollutants throughout your home.
Common signs include visible dust accumulation on vent covers, unexplained increases in energy bills due to reduced efficiency, musty odors when the system runs, or experiencing more allergy symptoms indoors.