Air conditioning is by far the most popular cooling system in the United States. In fact, over two-thirds of all homes use air conditioners and air conditioning accounts for 5% of the country’s total energy use. So just how does this cooling system work?
Your home’s air conditioner actually works in a similar way to your refrigerator. Energy – usually electricity – is used to replace warm air with cooler air. In the case of an air conditioner, your home is equipped with an evaporator, a cold indoor coil, and a condenser, a hot outdoor coil. The evaporator cools the air that is sent into the house while the condenser collects the warm air and pushes it outside. Typically the evaporator and condenser are made up of serpentine tubing, usually made out of copper, which is surrounded by aluminum fins.
In order to transfer the heat between the evaporator and the condenser, effectively pulling the heat out of your indoor air, your air conditioner uses a pump known as a compressor. The compressor forces the refrigerated air through the entire circuit of tubing and coils before pumping it outside.
While air conditioning is an extremely effective way to cool down your home, concerns have been raised over its cost (with an annual cost of more than $11 billion to homeowners in the United States) and potential harm to the environment. For most of the 20th century, air conditioners used chemicals called as chlorofluorocarbons (CFCs) as their refrigerant. Since CFC’s are harmful to the ozone layer, their production was stopped in 1995 and a new refrigerant, halogenated chlorofluorocarbons (HCFCs), was used. HCFCs are now being slowly replaced with an even more ozone-safe refrigerant, hydrofluorocarbons (HFCs). Air conditioning manufacturers have also given special attention to energy use, with modern models using up to 20-50% less energy than their predecessors. With these upgrades, the technology of air conditioners continues to improve as its popularity continues to increase.