text:
Air conditioning
From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Process of altering the properties of air to more favourable conditions
This article is about cooling of air. For Heating, ventilation and air conditioning, see HVAC. For air conditioning systems in vehicles, see Automobile air conditioning. For the Curved Air album, see Air Conditioning (album).
"A/C" redirects here. For other uses, see AC.
Air conditioning units outside a building
Air conditioning (often referred to as AC, A/C, air, or air con)[1] is the process of removing heat and moisture from the interior of an occupied space, to improve the comfort of occupants. Air conditioning can be used in both domestic and commercial environments. This process is most commonly used to achieve a more comfortable interior environment, typically for humans and animals; however, air conditioning is also used to cool/dehumidify rooms filled with heat-producing electronic devices, such as computer servers, power amplifiers, and even to display and store some delicate products, such as artwork.
Air conditioners often use a fan to distribute the conditioned air to an occupied space such as a building or a car to improve thermal comfort and indoor air quality. Electric refrigerant-based AC units range from small units that can cool a small bedroom, which can be carried by a single adult, to massive units installed on the roof of office towers that can cool an entire building. The cooling is typically achieved through a refrigeration cycle, but sometimes evaporation or free cooling is used. Air conditioning systems can also be made based on desiccants (chemicals which remove moisture from the air) and subterraneous pipes that can distribute the heated refrigerant to the ground for cooling.[2]
In the most general sense, air conditioning can refer to any form of technology that modifies the condition of air (heating, (de-)humidification, cooling, cleaning, ventilation, or air movement). In common usage, though, "air conditioning" refers to systems which cool air. In construction, a complete system of heating, ventilation, and air conditioning is referred to as HVAC.[3]
Contents
1 History
1.1 Evaporative cooling
1.2 Development of mechanical cooling
1.3 Electrical air conditioning
1.4 Refrigerant development
2 Operating principles
2.1 Refrigeration cycle
2.1.1 Heat pump unit
2.2 Evaporative cooling
2.3 Free cooling
3 Humidity control
3.1 Dehumidification and cooling
3.2 Dehumidification Program
3.3 Dehumidifier
4 Energy transfer
4.1 Seasonal energy efficiency ratio
5 Installation types
5.1 Window unit and packaged terminal
5.2 Split systems
5.2.1 Mini-split (ductless) system
5.2.2 Central (ducted) air conditioning
5.2.3 Multi-split system
5.3 Portable units
5.3.1 Portable split system
5.3.2 Portable hose system
5.3.3 Portable evaporative system
6 Uses
6.1 Comfort applications
6.1.1 Domestic usage
6.2 Process applications
7 Health effects
8 Environmental impacts
8.1 Power consumption and efficiency
8.2 Lower-energy alternatives
8.3 Automobile power consumption
8.4 Refrigerants
9 See also
10 References
11 External links
History[edit]
Evaporative cooling[edit]
Since prehistoric times, snow and ice were used for cooling. The business of harvesting ice during winter and storing for use in summer became popular towards the late 17th century.[4] This practice was replaced by mechanical ice-making machines.
The basic concept behind air conditioning is said to have been applied in ancient Egypt, where reeds were hung in windows and were moistened with trickling water. The evaporation of water cooled the air blowing through the window. This process also made the air more humid, which can be beneficial in a dry desert climate. In ancient Rome, water from aqueducts was circulated through the walls of certain houses to cool them. Other techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season.[5]
The 2nd-century Chinese mechanical engineer and inventor Ding Huan of the Han Dynasty invented a rotary fan for air conditioning, with seven wheels 3 m (10 ft) in diameter and manually powered by prisoners of the time.[6] In 747, Emperor Xuanzong (r. 712–762) of the Tang Dynasty (618–907) had the Cool Hall (Liang Dian 涼殿) built in the imperial palace, which the Tang Yulin describes as having water-powered fan wheels for air conditioning as well as rising jet streams of water from fountains. During the subsequent Song Dynasty (960–1279), written sources mentioned the air conditioning rotary fan as even more widely used.[7]
In the 17th century, the Dutch inventor Cornelis Drebbel demonstrated "Turning Summer into Winter" as an early form of modern air conditioning for James I of England by adding salt to water.[8]
Development of mechanical cooling[edit]
Three-quarters scale model of Gorrie's ice machine John Gorrie State Museum, Florida
Modern air conditioning emerged from advances in chemistry during the 19th century, and the first large-scale electrical air conditioning was invented and used in 1902 by American inventor Willis Carrier. The introduction of residential air conditioning in the 1920s helped enable the great migration to the Sun Belt in the United States.[citation needed]
In 1758, Benjamin Franklin and John Hadley, a chemistry professor at Cambridge University, conducted an experiment to explore the principle of evaporation as a means to rapidly cool an object. Franklin and Hadley confirmed that evaporation of highly volatile liquids (such as alcohol and ether) could be used to drive down the temperature of an object past the freezing point of water. They conducted their experiment with the bulb of a mercury thermometer as their object and with a bellows used to speed up the evaporation. They lowered the temperature of the thermometer bulb down to −14 °C (7 °F) while the ambient temperature was 18 °C (64 °F). Franklin noted that, soon after they passed the freezing point of water 0 °C (32 °F), a thin film of ice formed on the surface of the thermometer's bulb and that the ice mass was about 6 mm (1⁄4 in) thick when they stopped the experiment upon reaching −14 °C (7 °F). Franklin concluded: "From this experiment one may see the possibility of freezing a man to death on a warm summer's day."[9]
In 1820, English scientist and inventor Michael Faraday discovered that compressing and liquefying ammonia could chill air when the liquefied ammonia was allowed to evaporate. In 1842, Florida physician John Gorrie used compressor technology to create ice, which he used to cool air for his patients in his hospital in Apalachicola, Florida. He hoped to eventually use his ice-making machine to regulate the temperature of buildings. He even envisioned centralized air conditioning that could cool entire cities. Though his prototype leaked and performed irregularly, Gorrie was granted a patent in 1851 for his ice-making machine. Though his process improved the artificial production of ice, his hopes for its success vanished soon afterwards when his chief financial backer died and Gorrie did not get the money he needed to develop the machine. According to his biographer, Vivian M. Sherlock, he blamed the "Ice King", Frederic Tudor, for his failure, suspecting that Tudor had launched a smear campaign against his invention. Dr. Gorrie died impoverished in 1855, and the dream of commonplace air conditioning went away for 50 years.[citation needed]
James Harrison's first mechanical ice-making machine began operation in 1851 on the banks of the Barwon River at Rocky Point in Geelong, Australia. His first commercial ice-making machine followed in 1853, and his patent for an ether vapor compression refrigeration system was granted in 1855. This novel system used a compressor to force the refrigeration gas to pass through a condenser, where it cooled down and liquefied. The liquefied gas then circulated through the refrigeration coils and vaporized again, cooling down the surrounding system. The machine produced 3,000 kilograms (6,600 lb) of ice per day.[citation needed]
Though Harrison had commercial success establishing a second ice company back in Sydney in 1860, he later entered the debate over how to compete against the American advantage of ice-refrigerated beef sales to the United Kingdom. He wrote: "Fresh meat frozen and packed as if for a voyage, so that the refrigerating process may be continued for any required period", and in 1873 prepared the sailing ship Norfolk for an experimental beef shipment to the United Kingdom. His choice of a cold room system instead of installing a refrigeration system upon the ship itself proved disastrous when the ice was consumed faster than expected.[citation needed]
Electrical air conditioning[edit]
Willis Carrier
In 1902, the first modern electrical air conditioning unit was invented by Willis Carrier in Buffalo, New York[citation needed]. After graduating from Cornell University, Carrier found a job at the Buffalo Forge Company. While there, he began experimenting with air conditioning as a way to solve an application problem for the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, New York. The first air conditioner, designed and built in Buffalo by Carrier, began working on 17 July 1902.[citation needed]
Designed to improve manufacturing process control in a printing plant, Carrier's invention controlled not only temperature but also humidity. Carrier used his knowledge of the heating of objects with steam and reversed the process. Instead of sending air through hot coils, he sent it through cold coils (filled with cold water). The air was cooled, and thereby the amount of moisture in the air could be controlled, which in turn made the humidity in the room controllable. The controlled temperature and humidity helped maintain consistent paper dimensions and ink alignment. Later, Carrier's technology was applied to increase productivity in the workplace, and The Carrier Air Conditioning Company of America was formed to meet rising demand. Over time, air conditioning came to be used to improve comfort in homes and automobiles as well. Residential sales expanded dramatically in the 1950s.[citation needed]
In 1906, Stuart W. Cramer of Charlotte was exploring ways to add moisture to the air in his textile mill. Cramer coined the term "air conditioning", using it in a patent claim he filed that year as an analogue to "water conditioning", then a well-known process for making textiles easier to process. He combined moisture with ventilation to "condition" and change the air in the factories, controlling the humidity so necessary in textile plants. Willis Carrier adopted the term and incorporated it into the name of his company.[10]
Shortly thereafter, the first private home to have air conditioning was built in Minneapolis in 1914, owned by Charles Gates.[11] Realizing that air conditioning would one day be a standard feature of private homes, particularly in regions with warmer climate, David St. Pierre DuBose (1898-1994) designed a network of ductwork and vents for his home Meadowmont, all disguised behind intricate and attractive Georgian-style open moldings.[when?] This building is believed to be one of the first private homes in the United States equipped for central air conditioning.[12]
In 1945, Robert Sherman of Lynn, Massachusetts invented a portable, in-window air conditioner that cooled, heated, humidified, dehumidified, and filtered the air.[13]
Refrigerant development[edit]
Main article: Refrigerant
A modern R-134a hermetic refrigeration compressor
The first air conditioners and refrigerators employed toxic or flammable gases, such as ammonia, methyl chloride, or propane, that could result in fatal accidents when they leaked. Thomas Midgley, Jr. created the first non-flammable, non-toxic chlorofluorocarbon gas, Freon, in 1928. The name is a trademark name owned by DuPont for any chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), or hydrofluorocarbon (HFC) refrigerant. The refrigerant names include a number indicating the molecular composition (e.g., R-11, R-12, R-22, R-134A). The blend most used in direct-expansion home and building comfort cooling is an HCFC known as chlorodifluoromethane (R-22).
Dichlorodifluoromethane (R-12) was the most common blend used in automobiles in the U.S. until 1994, when most designs changed to R-134A due to the ozone-depleting potential of R-12. R-11 and R-12 are no longer manufactured in the U.S. for this type of application, so the only source for air-conditioning repair purposes is the cleaned and purified gas recovered from other air conditioner systems. Several non-ozone-depleting refrigerants have been developed as alternatives, including R-410A. It was first commercially used by Carrier Corp. under the brand name Puron.[citation needed]
Modern refrigerants have been developed to be more environmentally safe than many of the early chlorofluorocarbon-based refrigerants used in the early- and mid-twentieth century. These include HCFCs (R-22, as used in most U.S. homes before 2011) and HFCs (R-134a, used in most cars) have replaced most CFC use. HCFCs, in turn, are supposed to have been in the process of being phased out under the Montreal Protocol and replaced by HFCs such as R-410A, which lack chlorine.[14] HFCs, however, contribute to climate change problems. Moreover, policy and political influence by corporate executives resisted change.[15][16] Corporations insisted that no alternatives to HFCs existed. The environmental organization Greenpeace provided funding to a former East German refrigerator company to research an alternative ozone- and climate-safe refrigerant in 1992. The company developed a hydrocarbon mix of isopentane and isobutane, but as a condition of the contract with Greenpeace could not patent the technology, which led to its widespread adoption by other firms.[17][18][19] Their activist marketing first in Germany led to companies like Whirlpool, Bosch, and later LG and others to incorporate the technology throughout Europe, then Asia, although the corporate executives resisted in Latin America, so that it arrived in Argentina produced by a domestic firm in 2003, and then finally with giant Bosch's production in Brazil by 2004.[20][21]
In 1995, Germany made CFC refrigerators illegal.[22] DuPont and other companies blocked the refrigerant in the U.S. with the U.S. EPA, disparaging the approach as "that German technology".[21][23] Nevertheless, in 2004, Greenpeace worked with multinational corporations like Coca-Cola and Unilever, and later Pepsico and others, to create a corporate coalition called Refrigerants Naturally!.[22][24] Then, four years later, Ben & Jerry's of Unilever and General Electric began to take steps to support production and use in the U.S.[25] In 2011 the EPA decided in favor of the ozone- and climate-safe refrigerant for U.S. manufacture.[17][26][27]
Operating principles[edit]
This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2016) (Learn how and when to remove this template message)
Refrigeration cycle[edit]
Main article: Heat pump and refrigeration cycle
A simple stylized diagram of the refrigeration cycle: 1) condensing coil, 2) expansion valve, 3) evaporator coil, 4) compressor
Capillary expansion valve connection to evaporator inlet. Notice frost formation
In the refrigeration cycle, heat is transported from a colder location to a hotter area. As heat would naturally flow in the opposite direction, work is required to achieve this. A refrigerator is an example of such a system, as it transports the heat out of the interior and into its environment. The refrigerant is used as the medium which absorbs and removes heat from the space to be cooled and subsequently ejects that heat elsewhere.
Circulating refrigerant vapor enters the compressor, where its pressure and temperature are increased. The hot, compressed refrigerant vapor is now at a temperature and pressure at which it can be condensed and is routed through a condenser. Here it is cooled by air flowing across the condenser coils and condensed into a liquid. Thus, the circulating refrigerant removes heat from the system and the heat is carried away by the air. The removal of this heat can be greatly augmented by pouring water over the condenser coils, making it much cooler when it hits the expansion valve.
The condensed, pressurized, and still usually somewhat hot liquid refrigerant is next routed through an expansion valve (often nothing more than a pinhole in the system's copper tubing) where it undergoes an abrupt reduction in pressure. That pressure reduction results in flash evaporation of a part of the liquid refrigerant, greatly lowering its temperature. The cold refrigerant is then routed through the evaporator. A fan blows the interior warm air (which is to be cooled) across the evaporator, causing the liquid part of the cold refrigerant mixture to evaporate as well, further lowering the temperature. The warm air is therefore cooled and is pumped by an exhaust fan/ blower into the room. To complete the refrigeration cycle, the refrigerant vapor is routed back into the compressor. In order for the process to have any efficiency, the cooling/evaporative portion of the system must be separated by some kind of physical barrier from the heating/condensing portion, and each portion must have its own fan to circulate its own "kind" of air (either the hot air or the cool air).
Modern air conditioning systems are not designed to draw air into the room from the outside, they only recirculate the increasingly cool air on the inside. Because this inside air always has some amount of moisture suspended in it, the cooling portion of the process always causes ambient warm water vapor to condense on the cooling coils and to drip from them down onto a catch tray at the bottom of the unit from which it must then be routed outside, usually through a drain hole. As this moisture has no dissolved minerals in it, it will not cause mineral buildup on the coils. This will happen even if the ambient humidity level is low. If ice begins to form on the evaporative fins, it will reduce circulation efficiency and cause the development of more ice, etc. A clean and strong circulatory fan can help prevent this, as will raising the target cool temperature of the unit's thermostat to a point that the compressor is allowed to turn off occasionally. A failing thermistor may also cause this problem. Refrigerators without a defrost cycle may have this same issue. Dust can also cause the fins to begin blocking air flow with the same undesirable result: ice.
By running an air conditioner's compressor in the opposite direction, the overall effect can be completely reversed and the indoor area will become heated instead of cooled (see heat pump). The engineering of physical and thermodynamic properties of gas–vapor mixtures is called psychrometrics.
Heat pump unit[edit]
Main article: Heat pump
An example of an externally fitted AC unit which uses a heat pump system
A heat pump is an air conditioner in which the refrigeration cycle can be reversed, producing heating instead of cooling in the indoor environment. They are also commonly referred to as a "reverse cycle air conditioner". The heat pump is significantly more energy efficient than electric resistance heating. Some homeowners elect to have a heat pump system installed as a feature of a central air conditioner. When the heat pump is in heating mode, the indoor evaporator coil switches roles and becomes the condenser coil, producing heat. The outdoor condenser unit also switches roles to serve as the evaporator, and discharges cold air (colder than the ambient outdoor air).
Air-source heat pumps are more popular in milder winter climates where the temperature is frequently in the range of 4–13 °C (40–55 °F), because heat pumps become inefficient in more extreme cold. This is because ice forms on the outdoor unit's heat exchanger coil, which blocks air flow over the coil. To compensate for this, the heat pump system must temporarily switch back into the regular air conditioning mode to switch the outdoor evaporator coil back to being the condenser coil, so that it can heat up and defrost. A heat pump system will therefore have a form of electric resistance heating in the indoor air path that is activated only in this mode in order to compensate for the temporary indoor air cooling, which would otherwise be uncomfortable in the winter.
The icing problem becomes much more severe with lower outdoor temperatures, so heat pumps are commonly installed in tandem with a more conventional form of heating, such as a natural gas or oil furnace, which is used instead of the heat pump during harsher winter temperatures. In this case, the heat pump is used efficiently during the milder temperatures, and the system is switched to the conventional heat source when the outdoor temperature is lower.
Absorption heat pumps are a kind of air-source heat pump, but they do not depend on electricity to power them. Instead, gas, solar power, or heated water is used as a main power source. An absorption pump dissolves ammonia gas in water, which gives off heat. Next, the water and ammonia mixture is depressurized to induce boiling, and the ammonia is boiled off, which absorbs heat from the outdoor air.[citation needed]
Some more expensive fixed window air conditioning units have a true heat pump function. However, a window unit may only have an electric resistance heater.
Evaporative cooling[edit]
Main article: Evaporative cooler
An evaporative cooler
In very dry climates, evaporative coolers, sometimes referred to as swamp coolers or desert coolers, are popular for improving coolness during hot weather. An evaporative cooler is a device that draws outside air through a wet pad, such as a large sponge soaked with water. The sensible heat of the incoming air, as measured by a dry bulb thermometer, is reduced. The temperature of the incoming air is reduced, but it is also more humid, so the total heat (sensible heat plus latent heat) is unchanged. Some of the sensible heat of the entering air is converted to latent heat by the evaporation of water in the wet cooler pads. If the entering air is dry enough, the results can be quite substantial.
Evaporative coolers tend to feel as if they are not working during times of high humidity, when there is not much dry air with which the coolers can work to make the air as cool as possible for dwelling occupants. Unlike other types of air conditioners, evaporative coolers rely on the outside air to be channeled through cooler pads that cool the air before it reaches the inside of a house through its air duct system; this cooled outside air must be allowed to push the warmer air within the house out through an exhaust opening such as an open door or window.[28] These coolers cost less and are mechanically simple to understand and maintain.
Free cooling[edit]
Main article: Free cooling
Air conditioning can also be provided by a process called free cooling which uses pumps to circulate a coolant (typically water or a glycol mix) from a cold source, which in turn acts as a heat sink for the energy that is removed from the cooled space. Common storage media are deep aquifers or a natural underground rock mass accessed via a cluster of small-diameter boreholes, equipped with heat exchanger. Some systems with small storage capacity are hybrid systems, 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 because the temperature of the storage gradually increases during the cooling season, thereby declining its effectiveness.
Free cooling systems can have very high efficiencies, and are sometimes combined with seasonal thermal energy storage (STES) so the cold of winter can be used for summer air conditioning. Free cooling and hybrid systems are mature technology.[29]
Humidity control[edit]
This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2016) (Learn how and when to remove this template message)
Since humans perspire to provide natural cooling by the evaporation of perspiration from the skin, drier air (up to a point) improves the comfort provided. The comfort air conditioner is designed to create a 50% to 60% relative humidity in the occupied space.[citation needed]
Dehumidification and cooling[edit]
Refrigeration air conditioning equipment usually reduces the absolute humidity of the air processed by the system. The relatively cold (below the dewpoint) evaporator coil condenses water vapor from the processed air, much like an ice-cold drink will condense water on the outside of a glass. Therefore, water vapor is removed from the cooled air and the relative humidity in the room is lowered. The water is usually sent to a drain or may simply drip onto the ground outdoors. The heat is rejected by the condenser which is located outside of room to be cooled.
Dehumidification Program[edit]
Most modern air-conditioning systems feature a dehumidification cycle during which the compressor runs while the fan is slowed as much as possible[citation needed] to reduce the evaporator temperature and therefore condense more water. When the temperature falls below a threshold, both the fan and compressor are shut off to mitigate further temperature drops;[clarification needed] this prevents moisture on the evaporator from being blown back into the room.[citation needed] When the temperature rises again[clarification needed], the compressor restarts and the fan returns to low speed.
Occasionally, to thaw any ice produced, the fan runs with the compressor shut down; this function is less effective when ambient temperatures are low.[citation needed]
Inverter air conditioners use the inside coil temperature sensor to keep the evaporator as cold as possible. When the evaporator is too cold,[clarification needed] the compressor is slowed or stopped with the indoor fan running.[citation needed]
Dehumidifier[edit]
Main article: Dehumidifier
Typical portable dehumidifier
A specialized air conditioner that is used only for dehumidifying is called a dehumidifier. It also uses a refrigeration cycle, but differs from a standard air conditioner in that both the evaporator and the condenser are placed in the same air path. A standard air conditioner transfers heat energy out of the room because its condenser coil releases heat outside. However, since all components of the dehumidifier are in the same room, no heat energy is removed. Instead, the electric power consumed by the dehumidifier remains in the room as heat, so the room is actually heated, just as by an electric heater that draws the same amount of power.
In addition, if water is condensed in the room, the amount of heat previously needed to evaporate that water also is re-released in the room (the latent heat of vaporization). The dehumidification process is the inverse of adding water to the room with an evaporative cooler, and instead releases heat. Therefore, an in-room dehumidifier always will warm the room and reduce the relative humidity indirectly, as well as reducing the humidity directly by condensing and removing water.
Inside the unit, the air passes over the evaporator coil first, and is cooled and dehumidified. The now dehumidified, cold air then passes over the condenser coil where it is warmed up again. Then the air is released back into the room. The unit produces warm, dehumidified air and can usually be placed freely in the environment (room) that is to be conditioned.
Dehumidifiers are commonly used in cold, damp climates to prevent mold growth indoors, especially in basements. They are also used to protect sensitive equipment from the adverse effects of excessive humidity in tropical countries.
Energy transfer[edit]
In a thermodynamically closed system, any power dissipated into the system that is being maintained at a set temperature (which is a standard mode of operation for modern air conditioners) requires that the rate of energy removal by the air conditioner increase. This increase has the effect that, for each unit of energy input into the system (say to power a light bulb in the closed system), the air conditioner removes that energy.[30] To do so, the air conditioner must increase its power consumption by the inverse of its "efficiency" (coefficient of performance) times the amount of power dissipated into the system. As an example, assume that inside the closed system a 100 W heating element is activated, and the air conditioner has a coefficient of performance of 200%. The air conditioner's power consumption will increase by 50 W to compensate for this, thus making the 100 W heating element cost a total of 150 W of power.
It is typical for air conditioners to operate at "efficiencies" of significantly greater than 100%.[31] However, it may be noted that the input electrical energy is of higher thermodynamic quality (lower entropy) than the output thermal energy (heat energy).
Air conditioner equipment power in the U.S. is often described in terms of "tons of refrigeration", with each approximately equal to the cooling power of one short ton (2000 pounds or 907 kilograms) of ice melting in a 24-hour period. The value is defined as 12,000 BTU per hour, or 3517 watts.[32] Residential central air systems are usually from 1 to 5 tons (3.5 to 18 kW) in capacity.
Seasonal energy efficiency ratio[edit]
Main article: Seasonal energy efficiency ratio
For residential homes, some countries set minimum requirements for energy efficiency. In the United States, the efficiency of air conditioners is often (but not always) rated by the seasonal energy efficiency ratio (SEER). The higher the SEER rating, the more energy efficient is the air conditioner. The SEER rating is the BTU of cooling output during its normal annual usage divided by the total electric energy input in watt hours (W·h) during the same period.[33]
SEER = BTU ÷ (W·h)
this can also be rewritten as:
SEER = (BTU / h) ÷ W, where "W" is the average electrical power in Watts, and (BTU/h) is the rated cooling power.
For example, a 5000 BTU/h air-conditioning unit, with a SEER of 10, would consume 5000/10 = 500 Watts of power on average.
The electrical energy consumed per year can be calculated as the average power multiplied by the annual operating time:
500 W × 1000 h = 500,000 W·h = 500 kWh
Assuming 1000 hours of operation during a typical cooling season (i.e., 8 hours per day for 125 days per year).
Another method that yields the same result, is to calculate the total annual cooling output:
5000 BTU/h × 1000 h = 5,000,000 BTU
Then, for a SEER of 10, the annual electrical energy usage would be:
5,000,000 BTU ÷ 10 = 500,000 W·h = 500 kWh
SEER is related to the coefficient of performance (COP) commonly used in thermodynamics and also to the Energy Efficiency Ratio (EER). The EER is the efficiency rating for the equipment at a particular pair of external and internal temperatures, while SEER is calculated over a whole range of external temperatures (i.e., the temperature distribution for the geographical location of the SEER test). SEER is unusual in that it is composed of an Imperial unit divided by an SI unit. The COP is a ratio with the same metric units of energy (joules) in both the numerator and denominator. They cancel out, leaving a dimensionless quantity. Formulas for the approximate conversion between SEER and EER or COP are available.[34]
(1) SEER = EER ÷ 0.9
(2) SEER = COP × 3.792
(3) EER = COP × 3.413
From equation (2) above, a SEER of 13 is equivalent to a COP of 3.43, which means that 3.43 units of heat energy are pumped per unit of work energy.
The United States now requires that residential systems manufactured in 2006 have a minimum SEER rating of 13 (although window-box systems are exempt from this law, so their SEER is still around 10).
Installation types[edit]
Window unit and packaged terminal[edit]
How a window air conditioner works
Air conditioning window unit
Parts of a window unit
Window unit air conditioners are installed in an open window. The interior air is cooled as a fan blows it over the evaporator. On the exterior the heat drawn from the interior is dissipated into the environment as a second fan blows outside air over the condenser. A large house or building may have several such units, allowing each room to be cooled separately.
In 1971, General Electric introduced a popular portable in-window air conditioner designed for convenience and portability.[35]
Packaged terminal air conditioner (PTAC) systems are also known as wall-split air conditioning systems.[36] They are ductless systems. PTACs, which are frequently used in hotels, have two separate units (terminal packages), the evaporative unit on the interior and the condensing unit on the exterior, with an opening passing through the wall and connecting them. This minimizes the interior system footprint and allows each room to be adjusted independently. PTAC systems may be adapted to provide heating in cold weather, either directly by using an electric strip, gas, or other heater, or by reversing the refrigerant flow to heat the interior and draw heat from the exterior air, converting the air conditioner into a heat pump. While room air conditioning provides maximum flexibility, when used to cool many rooms at a time it is generally more expensive than central air conditioning.
The first practical semi-portable air conditioning unit was invented by engineers at Chrysler Motors and offered for sale starting in 1935.[37]
Split systems[edit]
Split-system air conditioners come in two forms: mini-split and central systems. In both types, the inside-environment (evaporative) heat exchanger is separated by some distance from the outside-environment (condensing unit) heat exchanger.
Mini-split (ductless) system[edit]
Outside part of a ductless split-type air conditioner
Indoor part of a ductless split-type air conditioner
A mini-split system typically supplies air conditioned and heated air to a single or a few rooms of a building.[38] Multi-zone systems are a common application of ductless systems and allow up to 8 rooms (zones) to be conditioned from a single outdoor unit. Multi-zone systems typically offer a variety of indoor unit styles including wall-mounted, ceiling-mounted, ceiling recessed, and horizontal ducted. Mini-split systems typically produce 9,000 to 36,000 Btu (9,500–38,000 kJ) per hour of cooling. Multi-zone systems provide extended cooling and heating capacity up to 60,000 Btu's.
Advantages of the ductless system include smaller size and flexibility for zoning or heating and cooling individual rooms. The inside wall space required is significantly reduced. Also, the compressor and heat exchanger can be located farther away from the inside space, rather than merely on the other side of the same unit as in a PTAC or window air conditioner. Flexible exterior hoses lead from the outside unit to the interior one(s); these are often enclosed with metal to look like common drainpipes from the roof. In addition, ductless systems offer higher efficiency, reaching above 30 SEER.[39]
The primary disadvantage of ductless air conditioners is their cost. Such systems cost about US$1,500 to US$2,000 per ton (12,000 BTU per hour) of cooling capacity. This is about 30% more than central systems (not including ductwork) and may cost more than twice as much as window units of similar capacity."[40]
An additional possible disadvantage is that the cost of installing mini splits can be higher than some systems. However, lower operating costs and rebates or other financial incentives—offered in some areas—can help offset the initial expense.[41]
Central (ducted) air conditioning[edit]
Central (ducted) air conditioning offers whole-house or large-commercial-space cooling, and often offers moderate multi-zone temperature control capability by the addition of air-louver-control boxes.
In central air conditioning, the inside heat-exchanger is typically placed inside the central furnace/AC unit of the forced air heating system which is then used in the summer to distribute chilled air throughout a residence or commercial building.
The heat-exchanger cools the air that is being forced through it by the furnace blower. As the warm air comes in contact with this cool surface the water in the air condenses. By pulling the water molecules from the air. According to the psychometric chart[42] as relative humidity decreases in order to feel cool you will have to lower the temperature even more. A common way to counteract this effect is by installing a whole-home humidifier.[43] Similarly, installing a high efficient system this need to turn the temperature down wont have such and influence on your energy costs.
Multi-split system[edit]
Multi-split system[44] - is a conventional split system, which is divided into two parts (evaporator and condenser) and allows cooling or heating of several rooms with one external unit. In the outdoor unit of this air conditioner there is a more powerful compressor, ports for connecting several traces and automation with locking valves for regulating the volume of refrigerant supplied to the indoor units located in the room.
Difference between split system and multi-split system:
Other common types of air conditioning system are multi-split systems, the difference between separate split system and multi-split system in several indoor units. All of them are connected to the main external unit, but the principle of their operation is similar to a simple split-system.
Its unique feature is the presence of one main external unit that connected to several indoor units. Such systems might be the right solution for maintaining the microclimate in several offices, shops, large living spaces. Just few of outdoor units do not worsen the aesthetic appearance of the building.The main external unit can be connected to several different indoor types: floor, ceiling, cassette, etc.
Multi-split system Installation:
Before selecting the installation location of air conditioner, several main factors need to be considered. First of all, the direction of air flow from the indoor units should not fall on the place of rest or work area. Secondly, there should not be any obstacles on the way of the airflow that might prevent it from covering the space of the premises as much as possible. The outdoor unit must also be located in an open space, otherwise the heat from the house will not be effectively discharged outside and the productivity of the entire system will drop sharply. It is highly advisable to install the air conditioner units in easily accessible places, for further maintenance during operation.
The main problem when installing a multi-split system is the laying of long refrigerant lines for connecting the external unit to the internal ones. While installing a separate split system, workers try to locate both units opposite to each other, where the length of the line is minimal. Installing a multi-split system creates more difficulties, since some of indoor units can be located far from the outside. The first models of multi-split systems had one common control system that did not allow you to set the air conditioning individually for each room. However, now the market has a wide selection of multi-split systems, in which the functional characteristics of indoor units operate separately from each other.
The selection of indoor units has one restriction - their total power should not exceed the capacity of the outdoor unit. In practice, however, it’s very common to see a multi-split system with a total capacity of indoor units greater than the outdoor capacity by at least 20%. But, it is wrong to expect better performance when all indoor units are turned on at the same time, since the total capacity of the whole system is limited by the capacity of the outdoor unit. Simply put, the outdoor unit will distribute all its power to all operating indoor units in such a way that some of the rooms may not have a very comfortable temperature level. However, the calculation of the total power is not simple, since it takes into account not only the nominal power of the units, but also the cooling capacity, heating, dehumidification, humidification, venting, etc.
Portable units[edit]
A portable air conditioner can be easily transported inside a home or office. They are currently available with capacities of about 5,000–60,000 BTU/h (1,500–18,000 W) and with or without electric-resistance heaters. Portable air conditioners are either evaporative or refrigerative.
The compressor-based refrigerant systems are air-cooled, meaning they use air to exchange heat, in the same way as a car radiator or typical household air conditioner does. Such a system dehumidifies the air as it cools it. It collects water condensed from the cooled air and produces hot air which must be vented outside the cooled area; doing so transfers heat from the air in the cooled area to the outside air.
Portable split system[edit]
A portable system has an indoor unit on wheels connected to an outdoor unit via flexible pipes, similar to a permanently fixed installed unit.
Portable hose system[edit]
Hose systems, which can be monoblock or air-to-air, are vented to the outside via air ducts. The monoblock type collects the water in a bucket or tray and stops when full. The air-to-air type re-evaporates the water and discharges it through the ducted hose and can run continuously.
A single-hose unit uses air from within the room to cool its condenser, and then vents it outside. This air is replaced by hot air from outside or other rooms (due to the negative pressure inside the room), thus reducing the unit's overall efficiency.[45]
Modern units might have a coefficient of performance of approximately 3 (i.e., 1 kW of electricity will produce 3 kW of cooling). A dual-hose unit draws air to cool its condenser from outside instead of from inside the room, and thus is more effective than most single-hose units. These units create no negative pressure in the room.
Portable evaporative system[edit]
Evaporative coolers, sometimes called "swamp coolers", do not have a compressor or condenser. Liquid water is evaporated on the cooling fins, releasing the vapor into the cooled area. Evaporating water absorbs a significant amount of heat, the latent heat of vaporisation, cooling the air. Humans and animals use the same mechanism to cool themselves by sweating.
Evaporative coolers have the advantage of needing no hoses to vent heat outside the cooled area, making them truly portable. They are also very cheap to install and use less energy than refrigerative air conditioners.
Uses[edit]
Air-conditioning engineers broadly divide air conditioning applications into comfort and process applications.
Comfort applications[edit]
An array of air conditioners outside a commercial office building
Comfort applications aim to provide a building indoor environment that remains relatively constant despite changes in external weather conditions or in internal heat loads.
Air conditioning makes deep plan buildings feasible, for otherwise they would have to be built narrower or with light wells so that inner spaces received sufficient outdoor air via natural ventilation. Air conditioning also allows buildings to be taller, since wind speed increases significantly with altitude making natural ventilation impractical for very tall buildings.[citation needed] Comfort applications are quite different for various building types and may be categorized as:
Commercial buildings, which are built for commerce, including offices, malls, shopping centers, restaurants, etc.
High-rise residential buildings, such as tall dormitories and apartment blocks
Industrial spaces where thermal comfort of workers is desired
Cars, aircraft, boats, which transport passenger or fresh goods
Institutional buildings, which includes government buildings, hospitals, schools, etc.
Low-rise residential buildings, including single-family houses, duplexes, and small apartment buildings
Sports stadiums, such as the University of Phoenix Stadium[46] and in Qatar for the 2022 FIFA World Cup.[47]
Women have, on average, a significantly lower resting metabolic rate than men.[48] Using inaccurate metabolic rate guidelines for air conditioning sizing can result in oversized and less efficient equipment,[48] and setting system operating setpoints too cold can result in reduced worker productivity.[49]
In addition to buildings, air conditioning can be used for many types of transportation, including automobiles, buses and other land vehicles, trains, ships, aircraft, and spacecraft.
Domestic usage[edit]
Typical residential central air conditioners in North America
Air conditioning is common in the US, with 88% of new single-family homes constructed in 2011 including air conditioning, ranging from 99% in the South to 62% in the West.[50] In Canada, air conditioning use varies by province. In 2013, 55% of Canadian households reported having an air conditioner, with high use in Manitoba (80%), Ontario (78%), Saskatchewan (67%), and Quebec (54%) and lower use in Prince Edward Island (23%), British Columbia (21%), and Newfoundland and Labrador (9%).[51] In Europe, home air conditioning is generally less common. Southern European countries such as Greece have seen a wide proliferation of home air-conditioning units in recent years.[52] In another southern European country, Malta, it is estimated that around 55% of households have an air conditioner installed.[53] In India AC sales have dropped by 40%[clarification needed] due to higher costs and stricter energy efficiency regulations.[54]
Process applications[edit]
Process applications aim to provide a suitable environment for a process being carried out, regardless of internal heat and humidity loads and external weather conditions. It is the needs of the process that determine conditions, not human preference. Process applications include these:
Chemical and biological laboratories
Cleanrooms for the production of integrated circuits, pharmaceuticals, and the like, in which very high levels of air cleanliness and control of temperature and humidity are required for the success of the process.
Environmental control of data centers
Facilities for breeding laboratory animals. Since many animals normally reproduce only in spring, holding them in rooms in which conditions mirror those of spring all year can cause them to reproduce year-round.
Food cooking and processing areas
Hospital operating theatres, in which air is filtered to high levels to reduce infection risk and the humidity controlled to limit patient dehydration. Although temperatures are often in the comfort range, some specialist procedures, such as open heart surgery, require low temperatures (about 18 °C, 64 °F) and others, such as neonatal, relatively high temperatures (about 28 °C, 82 °F).
Industrial environments
Mining
Nuclear power facilities
Physical testing facilities
Plants and farm growing areas
Textile manufacturing
In both comfort and process applications, the objective may be to not only control temperature, but also humidity, air quality, and air movement from space to space.
Health effects[edit]
In hot weather, air conditioning can prevent heat stroke, dehydration from excessive sweating and other problems related to hyperthermia. Heat waves are the most lethal type of weather phenomenon in developed countries. Air conditioning (including filtration, humidification, cooling and disinfection) can be used to provide a clean, safe, hypoallergenic atmosphere in hospital operating rooms and other environments where proper atmosphere is critical to patient safety and well-being. It is sometimes recommended for home use by people with allergies.
Poorly maintained water cooling towers can promote the growth and spread of microorganisms,[55] such as Legionella pneumophila, the infectious agent responsible for Legionnaires' disease, or thermophilic actinomycetes. As long as the cooling tower is kept clean (usually by means of a chlorine treatment), these health hazards can be avoided or reduced. Excessive air conditioning can have a negative effect on skin, causing it to dry out, and can also cause dehydration.[citation needed]
Environmental impacts[edit]
Power consumption and efficiency[edit]
Innovation in air conditioning technologies continues, with much recent emphasis placed on energy efficiency. Production of the electricity used to operate air conditioners has an environmental impact, including the release of greenhouse gases.
Cylinder unloaders are a method of load control used mainly in commercial air conditioning systems. On a semi-hermetic (or open) compressor, the heads can be fitted with unloaders which remove a portion of the load from the compressor so that it can run better when full cooling is not needed. Unloaders can be electrical or mechanical.
According to a 2015 government survey, 87% of the homes in the United States use air conditioning and 65% of those homes have central air conditioning. Most of the homes with central air conditioning have programmable thermostats, but approximately two-thirds of the homes with central air do not use this feature to make their homes more energy efficient.[56]
Lower-energy alternatives[edit]
Alternatives to continual air conditioning can be used with less energy, lower cost, and with less environmental impact. These include:[57]
In large commercial buildings, making windows able to be opened by occupants when the air outside is cool enough to be comfortable
Setting thermostats to around 82 °F (28 °C) and allowing workers to wear more climate-appropriate clothing, such as polo shirts and Bermuda shorts. This approach has worked for the Cool Biz campaign in Japan.
Passive cooling techniques, such as:
Natural ventilation under and through buildings
Operating windows to induce a stack effect breeze
Letting in cool air at night and closing windows during the day
Operating shades to reduce solar gain
Building slightly underground, to take advantage of unpowered conduction and geothermal mass
Placement of trees, architectural shades, windows (and using window coatings) to reduce solar gain
Thermal insulation placed to prevent heat from entering
Light-colored building materials reflect away more incoming infrared radiation
Using a fan if the air is below body temperature
Swamp coolers in hot but dry weather
Using a geothermal heat pump or ground-coupled heat exchanger
Using naturally cooler basement rooms more
Taking a siesta during the hottest part of the day
Sleeping outside on a porch or roof
Automobile power consumption[edit]
In an automobile, the A/C system will use around 4 horsepower (3 kW) of the engine's power, thus increasing fuel consumption of the vehicle.[58]
Refrigerants[edit]
The selection of the working fluids (refrigerants) has a significant impact not only on the performance of the air conditioners but on the environment as well. Most refrigerants used for air conditioning contribute to global warming, and many also deplete the ozone layer.[59] CFCs, HCFCs, and HFCs are potent greenhouse gases when leaked to the atmosphere.
The use of CFC as a refrigerant was once common, including the refrigerants R-11 and R-12 (sold under the brand name Freon-12). Freon refrigerants were commonly used during the 20th century in air conditioners due to their superior stability and safety properties. When they are released accidentally or deliberately, these chlorine-bearing refrigerants eventually reach the upper atmosphere.[60] Once the refrigerant reaches the stratosphere, UV radiation from the Sun homolytically cleaves the chlorine-carbon bond, yielding a chlorine radical. These chlorine radicals catalyze the breakdown of ozone into diatomic oxygen, depleting the ozone layer that shields the Earth's surface from strong UV radiation. Each chlorine radical remains active as a catalyst until it binds with another radical, forming a stable molecule and quenching the chain reaction.
Prior to 1994, most automotive air conditioning systems used R-12 as a refrigerant. It was replaced with R-134a refrigerant, which has no ozone depletion potential. Old R-12 systems can be retrofitted to R-134a by a complete flush and filter/dryer replacement to remove the mineral oil, which is not compatible with R-134a.
R22 (also known as HCFC-22) has a global warming potential about 1,800 times higher than CO2.[61] It was phased out for use in new equipment by 2010, and is to be completely discontinued by 2020. Although these gasses can be recycled when air conditioning units are disposed of, uncontrolled dumping and leaking can release gas directly into the atmosphere.
In the UK, the Ozone Regulations[62] came into force in 2000 and banned the use of ozone depleting HCFC refrigerants such as R22 in new systems. The Regulation banned the use of R22 as a "top-up" fluid for maintenance between 2010 (for virgin fluid) and 2015 (for recycled fluid). This means that equipment that uses R22 can still operate, as long as it does not leak. Although R22 is now banned, units that use the refrigerant can still be serviced and maintained.
The manufacture and use of CFCs has been banned or severely restricted due to concerns about ozone depletion (see also Montreal Protocol).[63][64] In light of these environmental concerns, beginning on November 14, 1994, the U.S. Environmental Protection Agency has restricted the sale, possession and use of refrigerant to only licensed technicians, per rules under sections 608 and 609 of the Clean Air Act.[65]
As an alternative to conventional refrigerants, other gases, such as CO2 (R-744), have been proposed.[66] R-744 is being adopted as a refrigerant in Europe and Japan. It is an effective refrigerant with a global warming potential of 1, but it must use higher compression to produce an equivalent cooling effect.[citation needed]
In 1992, a non-governmental organization, Greenpeace, was spurred by corporate executive policies and requested that a European lab find substitute refrigerants. This led to two alternatives, one a blend of propane (R290) and isobutane (R600a), and one of pure isobutane.[18][22] Industry resisted change in Europe until 1993, and in the U.S. until 2011, despite some supportive steps in 2004 and 2008 (see Refrigerant Development above).[27][67]
See also[edit]
Air conditioner inverter
Cassette air conditioner
Crankcase heater
Energy label
Ground-coupled heat exchanger
Heat pump
Hydronics
Ice storage air conditioning
List of home appliances
Louver
Refrigerant
Trombe wall
Seawater air conditioning
Working fluids
References[edit]
Jump up ^ "air con Definition in the Cambridge English Dictionary". dictionary.cambridge.org. Retrieved 1 March 2018.
Jump up ^ Darling, David. "Earth cooling tube". daviddarling.info. Retrieved 1 March 2018.
Jump up ^ McDowall, Robert (2006). Fundamentals of HVAC Systems. Elsevier. p. 3. ISBN 9780080552330.
Jump up ^ Nagengast, Bernard (February 1999). "A History of Comfort Cooling Using Ice" (PDF). ASHRAE Journal: 49. Retrieved 22 July 2013.
Jump up ^ Bahadori MN (February 1978). "Passive Cooling Systems in Iranian Architecture". Scientific American. 238 (2): 144–154. doi:10.1038/scientificamerican0278-144.
Jump up ^ Needham, Joseph (1991). Science and Civilisation in China, Volume 4: Physics and Physical Technology, Part 2, Mechanical Engineering. Cambridge University Press. pp. 99, 151, 233. ISBN 978-0-521-05803-2.
Jump up ^ Needham, Joseph (1991). Science and Civilisation in China, Volume 4: Physics and Physical Technology, Part 2, Mechanical Engineering. Cambridge University Press. pp. 134, 151. ISBN 978-0-521-05803-2.
Jump up ^ Laszlo, Pierre (2001). Salt: Grain of Life. Comumbia University Press. ISBN 9780231121989.
Jump up ^ Franklin, Benjamin (June 17, 1758). "Letter to John Lining". Retrieved 6 August 2014.
Jump up ^ [1], Carrier, Willis H., "Apparatus for treating air."
Jump up ^ "A Brief History of Air Conditioning". Popular Mechanics. Retrieved 2015-01-01.
Jump up ^ "Early University Benefactors" (PDF). Rizzoconferencecenter.com. Retrieved 2012-11-08.
Jump up ^ "Unsung Engineering Heros: Robert Sherman". Navlog.org. Retrieved 2015-06-10.
Jump up ^ "Air Conditioners & Dehumidifiers". Sylvane.
Jump up ^ Mate, John "Making a Difference: A Case Study of the Greenpeace Ozone Campaign" RECIEL 10:2 2001.
Jump up ^ Benedick, Richard Elliot Ozone Diplomacy Cambridge, MA: Harvard University 1991.
^ Jump up to: a b "Happy birthday, Greenfreeze!". Greenpeace. Retrieved 8 June 2015.
^ Jump up to: a b "Ozone Secretariat". United Nations Environment Programme. Archived from the original on 12 April 2015. Retrieved 8 June 2015.
Jump up ^ "Öko-Coup aus Ostdeutschland". Der Spiegel (in German). September 13, 2013. Retrieved 4 September 2015.
Jump up ^ "La Historia del "Greenfreeze"". Ilustrados.com. Retrieved 2015-06-10.
^ Jump up to: a b "Discurso de Frank Guggenheim no lançamento do Greenfreeze | Brasil". Greenpeace.org. Retrieved 2015-06-10.
^ Jump up to: a b c "Greenfreeze: a Revolution in Domestic Refrigeration". www.ecomall.com. Retrieved 8 June 2015.
Jump up ^ "Der Greenfreeze - endlich in den USA angekommen" (in German). Greenpeace.de. 2011-12-28. Retrieved 2015-06-10.
Jump up ^ "PepsiCo Brings First Climate-Friendly Vending Machines to the U.S." phx.corporate-ir.net. Retrieved 8 June 2015.
Jump up ^ "Climate-Friendly Greenfreezers Come to the United States". WNBC. Retrieved 8 June 2015.
Jump up ^ "GreenFreeze". Greenpeace.
^ Jump up to: a b "Significant New Alternatives Program: Substitutes in Household Refrigerators and Freezers". Epa.gov. Retrieved June 4, 2018.
Jump up ^ Shane Smith (2000). Greenhouse gardener's companion: growing food and flowers in your greenhouse or sunspace (2nd ed.). Fulcrum Publishing. p. 62. ISBN 978-1-55591-450-9.
Jump up ^ Snijders, Aart (2008). "ATES Technology Development and Major Applications in Europe" (PDF). Conservation for the Living Community Workshop (Toronto and Region Conservation Authority. IFTech International. Retrieved 1 March 2018.
Jump up ^ Kreider, Jan F., ed. (2001). Handbook of heating, ventilation, and air conditioning. CRC Press. ISBN 0-8493-9584-4.
Jump up ^ Winnick, J (1996). Chemical engineering thermodynamics. John Wiley and Sons. ISBN 0-471-05590-5.
Jump up ^ "NIST Guide to the SI". National Institute of Standards and Technology. Archived from the original on 28 May 2007. Retrieved 2007-05-18.
Jump up ^ "Energy Glossary – S". Energy Glossary. Energy Information Administration. Retrieved 2006-07-02.
Jump up ^ SEER conversion formulas from Pacific Gas and Electric. Web.archive.org (2007-12-02). Retrieved on 2012-01-09.
Jump up ^ Staff, Writer (2016-01-13). "Timeline: Bright ideas". The Boston Globe. Retrieved 2017-04-17.
Jump up ^ "PTAC Buying Guide". Sylvane.
Jump up ^ Hearst Magazines (June 1935). Popular Mechanics. Hearst Magazines. pp. 885–. ISSN 0032-4558. Retrieved 9 January 2012.
Jump up ^ "Mitsubishi Contractors Guide" (PDF). Mitsubishipro.com. p. 16. Archived from the original (PDF) on 2015-02-26. Retrieved 2015-06-10.
Jump up ^ "Mitsubishi Electric US, Inc. Cooling & Heating | HVAC". Mitsubishipro.com. 2010-02-17. Archived from the original on 2015-06-03. Retrieved 2015-06-10.
Jump up ^ "Ductless Mini-Split Air Conditioners". US Department of Energy. 2012-08-09. Retrieved 2013-06-14.
Jump up ^ "Ductless, mini-Split Heat Pumps". US Department of Energy. Retrieved 2013-06-19.
Jump up ^ http://web.uconn.edu/poultry/NE-127/Images/psc_01.gif
Jump up ^ https://www.thespruce.com/home-humidifier-types-4072878
Jump up ^ Trott, A. R.; Welch, T (2000). Refrigeration and Air-Conditioning. Great Britain: Reed Educational and Professional Publishing Ltd. p. 312. ISBN 0 7506 4219 X.
Jump up ^ "In the two hose design the exchanged air does not come from the interior of the room or house, but enters through the second hose". Experts123.com. Retrieved 2015-06-10.
Jump up ^ "Qatar promises air-conditioned World Cup". CNN. 2010-12-03.
Jump up ^ "BBC World Service - News - Qatar 2022: How to build comfortable stadiums in a hot climate". Bbc.co.uk. 2010-12-03. Retrieved 2012-11-08.
^ Jump up to: a b Kingma, Boris; van Marken Lichtenbelt, Wouter (3 August 2015). "Energy consumption in buildings and female thermal demand". Nature Climate Change. doi:10.1038/NCLIMATE2741.
Jump up ^ Lang, Susan (October 19, 2004). "Study links warm offices to fewer typing errors and higher productivity". Cornell Chronicle. Retrieved 25 September 2015.
Jump up ^ US Census Bureau (MCD): Cheryl Cornish, Stephen Cooper, Salima Jenkins. "Characteristics of New Housing". census.gov. CS1 maint: Uses authors parameter (link)
Jump up ^ "Statistics Canada - Households and the Environment Survey, 2013". The Daily - Households and the Environment Survey, 2013. Statistics Canada. 2015-03-10. Retrieved 2015-05-11.
Jump up ^ "Χρυσές" δουλειές για τις εταιρείες κλιματιστικών έφερε το κύμα καύσωνα (in Greek). Athens: Lambrakis Press. 2007-07-25. Retrieved 2008-06-30.
Jump up ^ "STĦARRIĠ DWAR ID-DĦUL U L-INFIQ TAL-FAMILJA 2008 /HOUSEHOLD BUDGETARY SURVEY 2008" (PDF). National Statistics Office, Maltz. Retrieved 2011-07-14.
Jump up ^ "High prices see air-conditioners' sales plunging 40% this summer". Timesofindia.indiatimes.com. Retrieved 30 May 2012.
Jump up ^ "Negative Health Effects of Central AC". livestrong.com. Archived from the original on 28 January 2013. Retrieved 21 February 2013.
Jump up ^ "One in eight U.S. homes uses a programmed thermostat with a central air conditioning unit". U.S. Energy Information Administration. U.S. Department of Energy. 2017-07-19. Retrieved 2017-07-20.
Jump up ^ Leon Neyfakh (21 July 2013). "How to live without air conditioning". The Boston Globe.
Jump up ^ "Impact of Vehicle Air-Conditioning on Fuel Economy" (PDF). National Renewable Energy Laboratory. Retrieved 6 February 2012.
Jump up ^ "Refrigerant Management Program Refrigerants Regulated". Californial Environmental Protection Agency. Archived from the original on 4 October 2013. Retrieved 22 April 2014.
Jump up ^ "CHEMICALS IN THE ENVIRONMENT: FREON 113 (CAS NO. 76-13-1) : prepared by OFFICE OF POLLUTION PREVENTION AND TOXICS, U.S. ENVIRONMENTAL PROTECTION AGENCY" (TXT). Epa.gov. August 1994. Retrieved 2015-06-10.
Jump up ^ "Chapter.2_FINAL.indd" (PDF). Retrieved 2010-08-09.
Jump up ^ "2010 to 2015 government policy: environmental quality". GOV.UK. 2015-05-08. Retrieved 2015-06-10.
Jump up ^ Sciencedaily.com Archived April 6, 2012, at the Wayback Machine.
Jump up ^ Schlossberg, Tatiana (August 9, 2016). "How Bad Is Your Air-Conditioner for the Planet?". NYT. Retrieved August 17, 2016.
Jump up ^ "Complying With The Section 608 Refrigerant Recycling Rule | Ozone Layer Protection - Regulatory Programs | US EPA". Epa.gov. Retrieved 2015-06-10.
Jump up ^ "The current status in Air Conditioning – papers & presentations". R744.com. Archived from the original on 2008-05-14. Retrieved 2010-08-09.
Jump up ^ "Greenfreeze F-Gas Victory! Greener Refrigerators Finally Legal in the U.S." Greenpeace.org. Archived from the original on 2015-06-12. Retrieved 2015-06-10.
External links[edit]
Media related to Air conditioners at Wikimedia Commons
Air Handling Units CFD Simulation on YouTube
U.S. Patent 808,897 Carrier's original patent
U.S. Patent 1,172,429
U.S. Patent 2,363,294
hide
v
t
e
Heating, ventilation and air conditioning
Fundamental concepts
Air changes per hour
Bake-out
Building envelope
Convection
Dilution
Domestic energy consumption
Enthalpy
Fluid dynamics
Gas compressor
Heat pump and refrigeration cycle
Heat transfer
Humidity
Infiltration
Latent heat
Noise control
Outgassing
Particulates
Psychrometrics
Sensible heat
Stack effect
Thermal comfort
Thermal destratification
Thermal mass
Thermodynamics
Vapour pressure of water
Technology
Absorption refrigerator
Air barrier
Air conditioning
Antifreeze
Automobile air conditioning
Autonomous building
Building insulation materials
Central heating
Central solar heating
Chilled beam
Chilled water
Constant air volume (CAV)
Coolant
Dedicated outdoor air system (DOAS)
Deep water source cooling
Demand-controlled ventilation (DCV)
Displacement ventilation
District cooling
District heating
Electric heating
Energy recovery ventilation (ERV)
Firestop
Forced-air
Forced-air gas
Free cooling
Heat recovery ventilation (HRV)
Hybrid heat
Hydronics
HVAC
Ice storage air conditioning
Kitchen ventilation
Mixed-mode ventilation
Microgeneration
Natural ventilation
Passive cooling
Passive house
Radiant heating and cooling system
Radiant cooling
Radiant heating
Radon mitigation
Refrigeration
Renewable heat
Room air distribution
Solar air heat
Solar combisystem
Solar cooling
Solar heating
Thermal insulation
Underfloor air distribution
Underfloor heating
Vapor barrier
Vapor-compression refrigeration (VCRS)
Variable air volume (VAV)
Variable refrigerant flow (VRF)
Ventilation
Components
Air conditioner inverter
Air door
Air filter
Air handler
Air ionizer
Air-mixing plenum
Air purifier
Air source heat pumps
Automatic balancing valve
Back boiler
Barrier pipe
Blast damper
Boiler
Centrifugal fan
Chiller
Condensate pump
Condenser
Condensing boiler
Convection heater
Cooling tower
Damper
Dehumidifier
Duct
Economizer
Electrostatic precipitator
Evaporative cooler
Evaporator
Exhaust hood
Expansion tank
Fan coil unit
Fan heater
Fire damper
Fireplace
Fireplace insert
Freeze stat
Flue
Freon
Fume hood
Furnace
Furnace room
Gas compressor
Gas heater
Gasoline heater
Geothermal heat pump
Grease duct
Grille
Ground-coupled heat exchanger
Heat exchanger
Heat pipe
Heat pump
Heating film
Heating system
High efficiency glandless circulating pump
High-efficiency particulate air (HEPA)
High pressure cut off switch
Humidifier
Infrared heater
Inverter compressor
Kerosene heater
Louver
Mechanical fan
Mechanical room
Oil heater
Packaged terminal air conditioner
Plenum space
Pressurisation ductwork
Process duct work
Radiator
Radiator reflector
Recuperator
Refrigerant
Register
Reversing valve
Run-around coil
Scroll compressor
Solar chimney
Solar-assisted heat pump
Space heater
Smoke exhaust ductwork
Thermal expansion valve
Thermal wheel
Thermosiphon
Thermostatic radiator valve
Trickle vent
Trombe wall
Turning vanes
Ultra-low particulate air (ULPA)
Whole-house fan
Windcatcher
Wood-burning stove
Measurement
and control
Air flow meter
Aquastat
BACnet
Blower door
Building automation
Carbon dioxide sensor
Clean Air Delivery Rate (CADR)
Gas sensor
Home energy monitor
Humidistat
HVAC control system
Intelligent buildings
LonWorks
Minimum efficiency reporting value (MERV)
OpenTherm
Programmable communicating thermostat
Programmable thermostat
Psychrometrics
Room temperature
Smart thermostat
Thermostat
Thermostatic radiator valve
Professions, trades,
and services
Architectural acoustics
Architectural engineering
Architectural technologist
Building services engineering
Building information modeling (BIM)
Deep energy retrofit
Duct leakage testing
Environmental engineering
Hydronic balancing
Kitchen exhaust cleaning
Mechanical engineering
Mechanical, electrical, and plumbing
Mold growth, assessment, and remediation
Refrigerant reclamation
Testing, adjusting, balancing
Industry organizations
ACCA
AMCA
ASHRAE
ASTM International
BRE
BSRIA
CIBSE
LEED
SMACNA
Health and safety
Indoor air quality (IAQ)
Passive smoking
Sick building syndrome (SBS)
Volatile organic compound (VOC)
See also
ASHRAE Handbook
Building science
Fireproofing
Glossary of HVAC terms
Template:Home automation
Template:Solar energy
Retrieved from "https://en.wikipedia.org/w/index.php?title=Air_conditioning&oldid=856424662"
Categories:
1902 introductions
American inventions
Ancient Egyptian technology
Ancient Roman technology
Automation
Chinese inventions
Cooling technology
Dutch inventions
Gas technologies
Home appliances
Hidden categories:
CS1: Julian–Gregorian uncertainty
CS1 German-language sources (de)
CS1 maint: Uses authors parameter
CS1 uses Greek-language script (el)
CS1 Greek-language sources (el)
Webarchive template wayback links
Articles with short description
Articles containing Chinese-language text
All articles with unsourced statements
Articles with unsourced statements from July 2014
Articles with unsourced statements from April 2018
All articles with vague or ambiguous time
Vague or ambiguous time from September 2015
Articles needing additional references from December 2016
All articles needing additional references
Articles with unsourced statements from June 2016
Articles with unsourced statements from October 2017
Wikipedia articles needing clarification from October 2017
Articles with unsourced statements from July 2018
Articles with unsourced statements from August 2011
Wikipedia articles needing clarification from May 2013
Articles with unsourced statements from April 2017
Articles with unsourced statements from June 2013
Navigation menu
Personal tools
Not logged in
Talk
Contributions
Create account
Log in
Namespaces
Article
Talk
Variants
Views
Read
Edit
View history
More
Search
Navigation
Main page
Contents
Featured content
Current events
Random article
Donate to Wikipedia
Wikipedia store
Interaction
Help
About Wikipedia
Community portal
Recent changes
Contact page
Tools
What links here
Related changes
Upload file
Special pages
Permanent link
Page information
Wikidata item
Cite this page
Print/export
Create a book
Download as PDF
Printable version
In other projects
Wikimedia Commons
Languages
العربية
Asturianu
Azərbaycanca
বাংলা
Български
Català
Čeština
Dansk
Deutsch
Eesti
Ελληνικά
Español
Esperanto
Euskara
فارسی
Français
Gaeilge
한국어
Հայերեն
हिन्दी
Hrvatski
Bahasa Indonesia
Iñupiak
Italiano
עברית
ಕನ್ನಡ
Қазақша
Кыргызча
Latviešu
Lietuvių
Magyar
മലയാളം
Bahasa Melayu
Mìng-dĕ̤ng-ngṳ̄
မြန်မာဘာသာ
Nederlands
日本語
Norsk
ਪੰਜਾਬੀ
ភាសាខ្មែរ
Polski
Português
Română
Русский
Sardu
Scots
සිංහල
Slovenčina
Slovenščina
Српски / srpski
Srpskohrvatski / српскохрватски
Suomi
Svenska
Tagalog
தமிழ்
ไทย
Tsetsêhestâhese
Türkçe
Українська
اردو
Tiếng Việt
Winaray
ייִדיש
粵語
中文
56 more
Edit links
This page was last edited on 25 August 2018, at 02:58 (UTC).
Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
Privacy policy
About Wikipedia
Disclaimers
Contact Wikipedia
Developers
Cookie statement
Mobile view
Enable previews

key: html

type: local

value: div

attrs: id class

values: mw-page-base noprint

values: mw-head-base noprint

value: a

attrs: id class lang

values: firstHeading firstHeading en

values: siteSub noprint

attrs: class href

values: mw-jump-link #mw-head

values: mw-jump-link #p-search

attrs: class style

values: shortdescription nomobile noexcerpt noprint searchaux

attrs: href title

values:
note
hatnote navigation-not-searchable

attrs: href class title

values:
/wiki/AC_(disambiguation)
mw-redirect mw-disambig
AC (disambiguation)

value: img

attrs: alt src width height class srcset data-file-width data-file-height

attrs: href class

value: b

values:
/wiki/Computer_server
mw-redirect
Computer server

values:
/wiki/Power_amplifier
mw-redirect
Power amplifier

values:
/wiki/Refrigeration_cycle
mw-redirect
Refrigeration cycle

values: checkbox button toctogglecheckbox toctogglecheckbox display:none

values:
/wiki/Aqueduct_(watercourse)
mw-redirect
Aqueduct (watercourse)

values:
/wiki/Han_Dynasty
mw-redirect
Han Dynasty

values:
/wiki/Fan_(mechanical)
mw-redirect
Fan (mechanical)

values:
/wiki/Tang_Dynasty
mw-redirect
Tang Dynasty

values:
/wiki/Song_Dynasty
mw-redirect
Song Dynasty

values:
/wiki/James_I_of_England
mw-redirect
James I of England

values: Edit section: Development of mechanical cooling

values:
/wiki/John_Gorrie_State_Museum
mw-redirect
John Gorrie State Museum

values: This claim needs references to reliable sources. (July 2014)

values:
noprint Inline-Template Template-Fact
white-space:nowrap;

values:
/wiki/Cambridge_University
mw-redirect
Cambridge University

values: Edit section: Electrical air conditioning

values: This claim needs references to reliable sources. (April 2018)

values:
/wiki/Brooklyn,_New_York
mw-redirect
Brooklyn, New York

values: David St. Pierre DuBose (page does not exist)

values: The time period mentioned near this tag is ambiguous. (September 2015)

values: Wikipedia:Manual of Style/Dates and numbers

values:
/wiki/Central_air_conditioning
mw-redirect
Central air conditioning

values: Robert Sherman (engineer) (page does not exist)

values:
/wiki/Gas_compressor
mw-redirect
Gas compressor

values:
/wiki/Methyl_chloride
mw-redirect
Methyl chloride

values:
/wiki/Thomas_Midgley,_Jr.
mw-redirect
Thomas Midgley, Jr.

attrs: alt src width height srcset data-file-width data-file-height

values: Help:Introduction to referencing with Wiki Markup/1

values: plainlinks metadata ambox ambox-content ambox-Refimprove

values:
/wiki/Condensing_coil
mw-redirect
Condensing coil

values:
/wiki/Evaporator_coil
mw-redirect
Evaporator coil

values:
/wiki/Gas_compressor#Temperature
mw-redirect
Gas compressor

values:
/wiki/Electric_resistance_heating
mw-redirect
Electric resistance heating

values: This claim needs references to reliable sources. (June 2016)

values:
/wiki/Sponge_(tool)
mw-redirect
Sponge (tool)

values: plainlinks metadata ambox ambox-content ambox-Unreferenced

values: This claim needs references to reliable sources. (October 2017)

values: Edit section: Dehumidification and cooling

values: The text near this tag may need clarification or removal of jargon. (October 2017)

values:
noprint Inline-Template
margin-left:0.1em; white-space:nowrap;

values: This claim needs references to reliable sources. (July 2018)

values:
/wiki/Electric_heater
mw-redirect
Electric heater

values:
/wiki/Tropical_countries
mw-redirect
Tropical countries

values: Edit section: Seasonal energy efficiency ratio

values:
/wiki/Energy_Efficiency_Ratio
mw-redirect
Energy Efficiency Ratio

values: Edit section: Window unit and packaged terminal

values:
/wiki/Chrysler_Motors
mw-redirect
Chrysler Motors

values: Edit section: Mini-split (ductless) system

values: Edit section: Central (ducted) air conditioning

values:
/wiki/Duct_(HVAC)
mw-redirect
Duct (HVAC)

values: Edit section: Portable evaporative system

values: This claim needs references to reliable sources. (August 2011)

values:
/wiki/Metabolic_rate
mw-redirect
Metabolic rate

values:
/wiki/Single-family_homes
mw-redirect
Single-family homes

values: The text near this tag may need clarification or removal of jargon. (May 2013)

values:
/wiki/Integrated_circuits
mw-redirect
Integrated circuits

values:
/wiki/Data_centers
mw-redirect
Data centers

values:
/wiki/Laboratory_animal
mw-redirect
Laboratory animal

values:
/wiki/Operating_theatre
mw-redirect
Operating theatre

values: This claim needs references to reliable sources. (April 2017)

values: Edit section: Power consumption and efficiency

values:
/wiki/Infrared_radiation
mw-redirect
Infrared radiation

values:
/wiki/Swamp_cooler
mw-redirect
Swamp cooler

values: Edit section: Automobile power consumption

values:
/wiki/Greenhouse_gases
mw-redirect
Greenhouse gases

values:
/wiki/Earth%27s_atmosphere
mw-redirect
Earth's atmosphere

values: This claim needs references to reliable sources. (June 2013)

values:
/wiki/Air_conditioner_inverter
mw-redirect
Air conditioner inverter

values:
/wiki/Seawater_air_conditioning
mw-redirect
Seawater air conditioning

values:
nofollow
external text
http://navlog.org/patent_1.html

values:
nofollow
external text
http://trca.on.ca/dotAsset/16551.pdf

values:
nofollow
external text
//www.worldcat.org/issn/0032-4558

values:
nofollow
external text
//doi.org/10.1038/NCLIMATE2741

values: Category:CS1 maint: Uses authors parameter

values:
/wiki/Lambrakis_Press
mw-redirect
Lambrakis Press

values:
nofollow
external text
http://www.nso.gov.mt/docs/HBS2008.pdf

values:
nofollow
external text
http://www.epa.gov/chemfact/f_freon.txt

values:
/wiki/Tatiana_Schlossberg
mw-redirect
Tatiana Schlossberg

values: -moz-column-width: 30em; -webkit-column-width: 30em; column-width: 30em; list-style-type: decimal;

values:
nofollow
external text
//www.google.com/patents/US808897

values:
nofollow
external text
//www.google.com/patents/US1172429

values:
nofollow
external text
//www.google.com/patents/US2363294

values:
/wiki/Demand-controlled_ventilation
mw-redirect
Demand-controlled ventilation

values:
/wiki/Solar_cooling
mw-redirect
Solar cooling

values:
/wiki/Solar_heating
mw-redirect
Solar heating

values: High efficiency glandless circulating pump

values:
/wiki/High-efficiency_particulate_air
mw-redirect
High-efficiency particulate air

values:
/wiki/High_pressure_cut_off_switch
mw-redirect
High pressure cut off switch

values:
/wiki/Mechanical_fan
mw-redirect
Mechanical fan

values:
/wiki/Intelligent_buildings
mw-redirect
Intelligent buildings

values: Mold growth, assessment, and remediation

values: Chartered Institution of Building Services Engineers

values: Leadership in Energy and Environmental Design

values: Sheet Metal and Air Conditioning Contractors' National Association

values: nowraplinks collapsible autocollapse navbox-inner mw-collapsible mw-made-collapsible

values: Category:CS1 German-language sources (de)

values: Category:CS1 uses Greek-language script (el)

values: Category:CS1 Greek-language sources (el)

values: Category:Webarchive template wayback links

values: Category:Articles with short description

values: Category:Articles containing Chinese-language text

values: Category:All articles with unsourced statements

values: Category:Articles with unsourced statements from July 2014

values: Category:Articles with unsourced statements from April 2018

values: Category:All articles with vague or ambiguous time

values: Category:Vague or ambiguous time from September 2015

values: Category:Articles needing additional references from December 2016

values: Category:All articles needing additional references

values: Category:Articles with unsourced statements from June 2016

values: Category:Articles with unsourced statements from October 2017

values: Category:Wikipedia articles needing clarification from October 2017

values: Category:Articles with unsourced statements from July 2018

values: Category:Articles with unsourced statements from August 2011

values: Category:Wikipedia articles needing clarification from May 2013

values: Category:Articles with unsourced statements from April 2017

values: Category:Articles with unsourced statements from June 2013

values: Discussion about edits from this IP address [ctrl-alt-n]

values: A list of edits made from this IP address [ctrl-alt-y]

values: You are encouraged to create an account and log in; however, it is not mandatory

values: You're encouraged to log in; however, it's not mandatory. [ctrl-alt-o]

values:
/wiki/Air_conditioning
View the content page [ctrl-alt-c]
c

values: Discussion about the content page [ctrl-alt-t]

values: p-namespaces navigation vectorTabs p-namespaces-label

values:
p-variants
navigation
vectorMenu emptyPortlet
p-variants-label

values: Past revisions of this page [ctrl-alt-h]

values: p-views navigation vectorTabs p-views-label

values:
p-cactions
navigation
vectorMenu emptyPortlet
p-cactions-label

values:
mw-wiki-logo
/wiki/Main_Page
Visit the main page

values:
/wiki/Main_Page
Visit the main page [ctrl-alt-z]
z

values: Featured content – the best of Wikipedia

values: Find background information on current events

values:
/wiki/Special:Random
Load a random article [ctrl-alt-x]
x

values: portal navigation p-navigation p-navigation-label

values: Guidance on how to use and edit Wikipedia

values: About the project, what you can do, where to find things

values: A list of recent changes in the wiki [ctrl-alt-r]

values: portal navigation p-interaction p-interaction-label

values: List of all English Wikipedia pages containing links to this page [ctrl-alt-j]

values: Recent changes in pages linked from this page [ctrl-alt-k]

values:
/wiki/Wikipedia:File_Upload_Wizard
Upload files [ctrl-alt-u]
u

values: Printable version of this page [ctrl-alt-p]

values: تكييف الهواء – Arabic

values:
interlanguage-link interwiki-ast
display: none;

values:
interlanguage-link interwiki-az
display: none;

values: শীতাতপ নিয়ন্ত্রণ ব্যবস্থা – Bangla

values:
interlanguage-link interwiki-bn
display: none;

values: Климатизация – Bulgarian

values:
interlanguage-link interwiki-bg
display: none;

values:
interlanguage-link interwiki-ca
display: none;

values:
interlanguage-link interwiki-cs
display: none;

values:
interlanguage-link interwiki-da
display: none;

values:
interlanguage-link interwiki-de
display: none;

values:
interlanguage-link interwiki-et
display: none;

values: Κλιματισμός – Greek

values:
interlanguage-link interwiki-eo
display: none;

values:
interlanguage-link interwiki-eu
display: none;

values: تهویه مطبوع – Persian

values:
interlanguage-link interwiki-fa
display: none;

values:
interlanguage-link interwiki-fr
display: none;

values:
interlanguage-link interwiki-ga
display: none;

values:
interlanguage-link interwiki-ko
display: none;

values: Օդափոխում – Armenian

values:
interlanguage-link interwiki-hy
display: none;

values: वातानुकूलन – Hindi

values:
interlanguage-link interwiki-hr
display: none;

values:
https://ik.wikipedia.org/wiki/Niglanaaq
Niglanaaq – Inupiaq
ik
ik
interlanguage-link-target

values:
interlanguage-link interwiki-ik
display: none;

values:
interlanguage-link interwiki-it
display: none;

values: מיזוג אוויר – Hebrew

values:
interlanguage-link interwiki-he
display: none;

values: ವಾತಾನುಕೂಲ (ಉಪಕರಣ) – Kannada

values:
interlanguage-link interwiki-kn
display: none;

values: Ауа кондициялау – Kazakh

values:
interlanguage-link interwiki-kk
display: none;

values: Абаны кондициялоо – Kyrgyz

values:
interlanguage-link interwiki-ky
display: none;

values:
interlanguage-link interwiki-lv
display: none;

values:
interlanguage-link interwiki-lt
display: none;

values:
interlanguage-link interwiki-hu
display: none;

values: എയർ കണ്ടീഷണർ – Malayalam

values:
interlanguage-link interwiki-ml
display: none;

values:
interlanguage-link interwiki-cdo
display: none;

values: လေညှိခြင်း – Burmese

values:
interlanguage-link interwiki-my
display: none;

values:
interlanguage-link interwiki-nl
display: none;

values:
interlanguage-link interwiki-ja
display: none;

values:
interlanguage-link interwiki-no
display: none;

values: ਏਅਰ ਕੰਡੀਸ਼ਨਿੰਗ – Punjabi

values:
interlanguage-link interwiki-pa
display: none;

values: ម៉ាស៊ីនត្រជាក់ – Khmer

values:
interlanguage-link interwiki-km
display: none;

values:
interlanguage-link interwiki-pl
display: none;

values:
interlanguage-link interwiki-pt
display: none;

values:
interlanguage-link interwiki-ro
display: none;

values: Кондиционирование воздуха – Russian

values:
interlanguage-link interwiki-sc
display: none;

values:
interlanguage-link interwiki-sco
display: none;

values: වායු සමන – Sinhala

values:
interlanguage-link interwiki-si
display: none;

values:
interlanguage-link interwiki-sk
display: none;

values:
interlanguage-link interwiki-sl
display: none;

values:
interlanguage-link interwiki-sr
display: none;

values:
interlanguage-link interwiki-sh
display: none;

values:
interlanguage-link interwiki-fi
display: none;

values:
interlanguage-link interwiki-sv
display: none;

values:
https://tl.wikipedia.org/wiki/Erkon
Erkon – Tagalog
tl
tl
interlanguage-link-target

values:
interlanguage-link interwiki-tl
display: none;

values: வளிப் பதனம் – Tamil

values:
interlanguage-link interwiki-ta
display: none;

values: เครื่องปรับอากาศ – Thai

values:
interlanguage-link interwiki-th
display: none;

values:
interlanguage-link interwiki-chy
display: none;

values:
https://tr.wikipedia.org/wiki/Klima
Klima – Turkish
tr
tr
interlanguage-link-target

values:
interlanguage-link interwiki-tr
display: none;

values: Кондиціонування повітря – Ukrainian

values:
interlanguage-link interwiki-uk
display: none;

values: ایئر کنڈیشنگ – Urdu

values:
interlanguage-link interwiki-vi
display: none;

values:
https://war.wikipedia.org/wiki/Erkon
Erkon – Waray
war
war
interlanguage-link-target

values:
interlanguage-link interwiki-war
display: none;

values: לופטקילער – Yiddish

values:
interlanguage-link interwiki-yi
display: none;

values:
interlanguage-link interwiki-zh-yue
display: none;

values: All languages (initial selection from common choices by you and others)

values: /static/images/wikimedia-button-1.5x.png 1.5x, /static/images/wikimedia-button-2x.png 2x

values: /static/images/poweredby_mediawiki_132x47.png 1.5x, /static/images/poweredby_mediawiki_176x62.png 2x

values:
suggestions
display: none; font-size: 13px;

values: mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject page-Air_conditioning rootpage-Air_conditioning skin-vector action-view