by Jessica Gezon
Keeping cool is an essential part of life during the hot summer months, and the right air conditioner will not only make you more comfortable; it can save you money. Knowing how air conditioners work can help you choose the right unit for your abode; size, circulation, power and filters all factor into your decision.
Refrigeration: Air conditioners work in essentially the same way a refrigerator works: High-pressure Freon is cooled, and the change in state from gas to liquid creates a severe change in temperature. As the warm air from your home (or office or car, the principle is the same) passes over the cooled tubes, the heat is absorbed by the Freon, leaving cold air to be blown back into your home and the warm air expelled (generally out a window or ventilation tube).
Humidity: Humans use perspiration to lower their body temperature, so in general, drier air provides a more comfortable experience than humid air. Just as a cold drink will collect condensation on the outside of a cup, the evaporator coil condenses water vapor and disperses dry air so your body can cool itself. There are dehumidifiers available; they provide the dry air without the cooling factor of an air conditioning unit due to the placement of a heat exchanger between the exhaust and intake areas.
Filters: Many of today's air conditioners have built-in filters. Since the air is being circulated anyway, it's an easy step to pass the air through a filter. Filters are especially important if air will be circulating from outside into your home. Passing the air through a filter can catch pollen, dirt, smoke and other allergens before they invade your home.
Swamp coolers: Swamp coolers, also known as evaporative coolers, operate on the same basic principle as other conditioners, pumping cool air into the room of your choice, but the way they cool the air is different and leads to some limitations. Swamp coolers work by passing air through a damp pad. Once the air is cooled, it's blown into the house. Because the air is cooled by passing through water, the resulting air is damp; this means that swamp coolers work well only in hot, dry climates and that the air produced is somewhat humid.
Central air: Central air is the layman's term for housewide air conditioning. Instead of cooling a single room, the unit has a large enough compressor to process enough air for a whole house. The air conditioner will be housed outside so hot air can be expelled away from the home. A system of internal ducts delivers the air.
Window units: Window units work exactly the same way as central air units, but on a smaller scale. As the name indicates, they sit in a window and expel hot air directly outside. They're designed to cool only a single room rather than an entire home.