How Air Conditioners Work The first modern air conditioning system was developed in 1902 by a young electrical engineer named Willis Haviland Carrier. It was designed to solve a humidity problem at the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, N.Y. Paper stock at the plant would sometimes absorb moisture from the warm summer air, making it difficult to apply the layered inking techniques of the time. Carrier treated the air inside the building by blowing it across chilled pipes. The air cooled as it passed across the cold pipes, and since cool air can't carry as much moisture as warm air, the process reduced the humidity in the plant and stabilized the moisture content of the paper. Reducing the humidity also had the side benefit of lowering the air temperature -- and a new technology was born. Carrier realized he'd developed something with far-reaching potential, and it wasn't long before air-conditioning systems started popping up in theaters and stores, making the long, hot summer months much more comfortable [source: Time].

The actual process air conditioners use to reduce the ambient air temperature in a room is based on a very simple scientific principle. The rest is achieved with the application of a few clever mechanical techniques. Actually, an air conditioner is very similar to another appliance in your home -- the refrigerator. Air conditioners don't have the exterior housing a refrigerator relies on to insulate its cold box. Instead, the walls in your home keep cold air in and hot air out. Let's move on to the next page where we'll discover what happens to all that hot air when you use your air conditioner. While most people associate air conditioning with cold, the science behind making your home cooler actually deals with the transfer of heat. When that heat is lost, or removed, the remaining cold air cools your home.  In order to understand this system better, let’s look at the major components. Your central air conditioning system has two key components: the indoor unit, and the outdoor unit.

They work in tandem to keep your home comfortable year-round. The indoor unit is typically located in a closet or basement, and is near where your furnace filter is located. price of a new central air conditioning unitThe unit consists of a coil box that contains what is called an evaporator.  alternative to ac unitThe evaporator allows for the refrigerant – a cooling fluid inside the coil piping sometimes known by a brand name such as Freon™ – to evaporate and absorb heat. fix ac unitOnce the heat is absorbed from inside your home, it leaves nothing but cool air to be sent back into your home. Just as water absorbs heat from your stove in order to boil (or evaporate) refrigerant absorbs heat from your house. This means that both water and refrigerant turn from liquid to vapor as they absorb heat.

The outdoor unit is usually located in the rear or side of your house and it is where the heat from inside your home is dispersed. It contains the compressor, condenser coil and a fan. The heat absorbed from your home’s air is transferred to the refrigerant and then pumped to the outdoor unit. As this heat is absorbed and moved by the refrigerant to the outdoor coil, it passes through the compressor. The compressor in your air conditioning system has the primary job of moving the refrigerant throughout the system. This is important as we can then keep reusing the refrigerant to cool our house. The refrigerant is compressed to a higher pressure, and moved through the outdoor coil known as the condenser. As the refrigerant passes through the condenser, a fan delivers ambient air across the condenser coil causing it to cool. As the process completes, the heat from inside your house is dispersed to the air outside your house. The refrigerant is then pumped back indoors and the whole process repeats.

Did you know that making your home cooler was actually less about increasing cold air and more about removing existing heat? Simple Ways to Extend the Life of Your AC and Heating System An  can change the temperature, humidity or general quality of the air. More specifically, an air conditioner makes your home cooler, by drawing heat energy out of the house and transferring that heat to the outdoors, then replacing the air inside your home with cooler air. The air conditioner in a central heating and cooling system provides cool air through ductwork inside your home, by providing a process that draws out the warm air inside, removing its heat. system, the compressor condenses and circulates the refrigerant through the outdoor unit, changing it from a gas to a liquid. liquid is then forced through the indoor evaporator coil or coolingThe indoor unit’s fan circulates the inside air to pass across the evaporator fins. The evaporator’s metal fins exchange the

thermal energy with the air around it. There, the refrigerant turns from liquid into vapor, removing any heat from the surrounding air. the heat is removed from the air, the air is cooled and blown back From that point, the condenser or outdoor unit then turns the refrigerant vapor back into a liquid, removing any heat. the fluid leaves the evaporator again, it is a cool, low-pressure gas, eventually returning to the condensor to begin its trip all overThis process continues again and again until your home reaches the cooling temperature you want, as programmed and sensed by yourScience of Summer: How Does Air Conditioning Work? Editor's Note: In this weekly series, LiveScience looks at scientific aspects of the summer season. As August heats up around the country, for many, summer's swelter will mercifully be kept in check by air conditioning. The technology has had a profoundly comforting impact on modern life, and about 87 percent of American homes these days have some form of air conditioning, according to the Energy Information Administration.

So how does a typical air conditioning unit work and keep you sane during the heat of summer? The basic concept is that a chemical called a refrigerant loops from inside the home to outside and back again, absorbing and casting out heat in the process. The refrigerant cools and then re-enters the home, starting the cycle anew, explained Glenn Hourahan, senior vice president at the Air Conditioning Contractors of America. Hourahan said that the two refrigerants commonly used in residential air conditioners are R-22 and the newer R-410A, both of which are chemically known as hydrochlorofluorocarbons, or HCFCs. These chemicals go back and forth from a liquid to a gaseous state very easily, and it is these so-called phase transitions that make HCFCs so useful as refrigerants. A common phase transition we've all seen is when liquid water is heated and evaporates into a gas, or water vapor. The same goes for the refrigerant: it absorbs heat in its liquid state, transforming into a gas.

The refrigerant is then forced to return to being a liquid, expelling the heat it absorbed and thus made ready to soak up heat once again. [The Mysterious Physics of 7 Everyday Things] An air conditioning breakdown An air conditioning system essentially has four parts, said Hourahan: an evaporator, a compressor, a condenser and an expansion device. The part inside the home where the refrigerant evaporates is the evaporator, naturally. Fans in the home blow air across the evaporator's coils. "As air from the house moves across the evaporator, refrigerant within the coil picks up the temperature of the air," said Hourahan. "The refrigerant is absorbing heat from the air and turns from a liquid to a vapor. It went from being a cold liquid to a hotter vapor, and at the same time, the air had heat removed from it, so the air went from being warmer to colder." The vaporized refrigerant then passes into the compressor, which is located outside in the air conditioning unit adjacent to a home (or often on the roof of a business), along with the condenser.

As the name implies, the compressor compresses the gas to a state of higher pressure and higher temperature. From there, the hot, pressurized gas flows over the third component, the condenser. Here, the gas is condensed back into its liquid state as heat is radiated away. Outdoor units often have metal fins on them to help dissipate the heat more quickly. The cooled-off liquid is now returned into the home. The expansion device regulates the flow of liquid refrigerant into the evaporator, where just as before it will absorb heat and change phase from a liquid into a low-pressure gas. Removing heat is not all that an air conditioner does as it, ahem, conditions the air. Humidity — the amount of water vapor in the air — is a major factor in how our bodies feel the heat; a more humid environment prevents sweat from evaporating off the skin, which helps to whisk away unwanted bodily warmth. [7 Common Summer Health Woes] So, in order to render the environment inside a home or business more comfortable, air conditioners also dehumidify.

"As the air moves across the evaporator coil, the coil absorbs heat and also wrings out moisture," said Hourahan. "The air now has a cooler temperature and is drier, so when it comes out of the registers [vents], it mixes with room air and makes the room more comfortable." All that water leached out of the air by air conditioners can pool in or drain out of the unit, especially on humid days. The modern air conditioning unit came about with the goal of humidity control. In 1902, engineer Willis Carrier drew up a method to remove irksome humidity from the air at a printing company in Brooklyn, N.Y. "The very first unit by Willis Carrier was not for temperature control, but for humidity control," said Hourahan. "You got cooling as a byproduct." It would take about another six decades before air conditioners really became widespread in America. "In the '30s and '40s, they started going into homes — rich homes," said Hourahan. "It wasn't until the '50s and '60s that air conditioning started going into middle-class homes."