View A Video on Air Conditioners - A Quick Introduction
Air conditioners are devices that remove heat from the air through use of a compressor, a condenser, an expansion valve, a thermostat and a series of motorized fans. Some units may be connected to air ducts or air handling equipment. Components of these units are usually made from metal, commonly stainless steel or aluminum.
Air conditioners are widely used in residential, commercial and industrial settings and air conditioner manufacturers design a variety of models to accommodate many different environments and needs. Air conditioning systems all have the same internal components. After the air is cooled, it needs to be released into the space. Air handling equipment circulates conditioned air by either blowing it directly into a space or into air ducts. Air handlers are used with furnaces as well as air conditioning systems. Air conditioning units are usually placed in buildings where fans or natural breezes are inadequate because of temperature, air disturbance or pollution. Air conditioning systems often use air filters to maintain air quality and avoid spreading germs, pollutants or other unwanted irritants. Variations in size, power and air delivery help consumers choose the right kind of unit for their needs. Examples include cabinet air conditioners, ductless air conditioner, central air conditioners and split air conditioner, to name just a few. The size and power of the unit is the most important specification. Portable air conditioners are easily moved from one area of a facility to another but can only provide limited cooling. They are also known as spot coolers and are frequently positioned in places where the main air conditioning system does not reach or where additional cooling is needed.
Next in size are cabinet air conditioners, which are contained in a boxlike enclosure. The cabinet enclosure helps protect the internal components from dust, water, liquid spray, accidental contact and other possible interferences. The unit is generally attached to a system of air ducts or air handling equipment that delivers the cool air throughout a building. In some cases, however, ductwork cannot be installed in a safe or cost effective way. Ductless air conditioners blow the air into a space directly from the unit. Ductless air conditioners are able to cool larger areas than portable or window mounted air conditioners because multiple evaporators can be connected to a single compressor. Central air conditioners are powerful enough to cool an entire building. For residential buildings, the unit is usually placed beside a structure; for industrial or commercial systems the units may be on top of the roof. Split air conditioners separate the hot condensing unit from the cool air handling unit. The hot components are kept outside in order to maximize the efficiency of the air conditioning. There may be one large condensing unit or a number of small ones to cool various areas of the building differently. Split air conditioners are ineffective for multi-level structures; large buildings require more power. Commercial air conditioners are used to cool commercial buildings such as offices and retail stores. They generally use central air conditioning systems to keep the entire building at one consistent, comfortable temperature. Similarly, industrial air conditioners are used for cooling in a variety of industrial applications such as manufacturing, shipping and warehouse facilities.
Air conditioners have a thermostat that deforms in accordance with the current air temperature. When it reaches a predetermined temperature a sensor causes the unit to turn on until the thermostat measures the air temperature at a lower level. A/C units, as they are frequently abbreviated, use a chemical called a refrigerant that can change quickly from a gas to a liquid. Freon is the most commonly used refrigerant. This chemical is contained inside coils within the body of the main unit. The compressor causes the refrigerant to change from a cool gas to a hot gas under pressure. As the gas runs through the coils, it condenses into a liquid as the heat dissipates. It is forced through the small opening of the expansion valve which helps it evaporate back into a cold low-pressure gas. This gas runs through the coils to absorb heat from the air, cooling the space.
Air conditioners have fairly basic mechanics and technology. Despite their simplicity, these devices are still considered new developments in the field of cooling products. Electric fans were developed during the Industrial Revolution in the late 19th century. Changes in materials and blades gave rise to the ceiling fan and personal fans for upper class households. From the 1920s to 1950s, steel fans became more affordable and were widely manufactured. Central air conditioning came about in the 1960s and began to replace the use of fans in offices and businesses. Today, air conditioners are widespread throughout many buildings; most new homes and schools built within the last twenty years have central air conditioning. Materials and design techniques continue to advance the efficiency and power of air conditioners. Enclosures and ducts are becoming better insulated, which helps keep the cool air in the system without escape. Compressors, condensers and motors are being developed by innovative manufacturers who strive for more power with less energy, noise or vibration. Older systems may drip water as they work to remove heat from the air, which is undesirable in many environments and models are being worked with to minimize that possibility. Steel remains the most widely used material because of its strength, durability and thermal properties.
Air Conditioner Types
produce cooling units used in homes, offices, commercial and industrial buildings.
- Air conditioning systems consist of all the components needed to effectively circulate cooled and conditioned air throughout a space.
- Air conditioning units are the parts of a system that perform the actual process.
- An air handler distributes the air from a furnace or air conditioner through ducts and vents within a facility.
- A cabinet air conditioner is held in a protective enclosure.
- Central air conditioners provide cooling for an entire building. are strong enough to handle large spaces. consist of
quiet, compact, indoor air distribution units and an efficient outdoor
compressor linked by refrigerant lines.
- Industrial air conditioners are used to provide cooling in industrial environments.
- are often used in temporary environments, such as construction or other
- Split air conditioners are divided into two parts; one contains hot equipment and is placed outside while the other cool component is located within the facility.
- Spot cooling is performed by portable or mobile air conditioners for precise temperature control of electronics, machinery or a room.
Air Conditioner Terms
A shell-shaped device that is incorporated into an HVAC (heating, ventilation,
air conditioning) system within the suction line in order to protect the
compressor from liquids.
driven by a compressor.
- Drying air
or gas by holding moisture vapor on a desiccant surface without mixing
with its molecular structure.
- The indoor
unit of an air conditioning system that provides conditioned air into
a space. An air handler consists of a heat exchange coil, filters and
A unit of measurement of heat or energy. One BTU is the amount of heat
needed to raise or reduce the temperature of one pound of water by one
- The maximum amount
of heat energy that can be removed from or added to a medium by an HVAC
- Also referred to
as the "heart" of a refrigerating or a/c system, a compressor
is a pump that uses pressure to move refrigerant through pipes between
an outdoor condensing unit and an indoor evaporating unit.
- The process
of changing air into liquid.
- A substance
suitable for absorbing and adsorbing moisture.
The utilization of a central utility system to heat or cool large residential
and industrial areas.
- A device used
to distribute air.
- A device used
for the removal of solid and liquid particles.
with an evaporator that does not have a fan to circulate the air.
- A device capable of transferring heat from one place or medium
- Mass of
water vapor present per unit volume of air, usually measured as grains/ft3,
lbs/ft3 or grams/ft3.
total pressure at the inlet flange of the compressor.
- The required rate
of heat removal.
A device that separates condensate from an air stream.
- A heat
exchanger that lowers the temperature of the inlet air with the help
of the outgoing cold air. In the process, the outgoing air is reheated
by the incoming air.
- The medium
of heat transfer in a refrigeration system that picks up heat by evaporating
at a low temperature and rejects heat by condensing at a high temperature.
- A regenerative
pressure exerted on a liquid and vapor surface.