An efficient system and well-sealed ducts are critical in keeping a home cool. See how a well-planned HVAC system can optimize comfort.
Central, or whole-home, air-conditioning (AC) was once a luxury. These days, it's standard equipment on many homes. A good AC system will not only cool a home, but help control humidity as well. It's important for homeowners to understand their AC system components, how they work, and how to make sure contractors install the correctly sized system. "An ounce of prevention is definitely worth a pound of cure when it comes to AC systems," says Dave Moody, an AC industry pro with Service Experts, "Regular maintenance can make the system more efficient and make it last longer, keeping you comfortable for less."
AC System Components
Your AC is part of the heating, ventilating, and air-conditioning system (HVAC). It is either paired with a furnace or it is part of the cooling cycle of a heat pump unit. As a matter of fact, a heat pump is simply an air-conditioner that cools in the summer but then runs in reverse in the winter, heating the home. Still, both furnace-paired and heat pump systems will have similar components. Some components are installed inside the home while others are placed outside the home.
The key ingredient in any AC system is refrigerant (more commonly known by its trade name, Freon) which is compressed by a compressor into a high pressure gas where it's released into a closed loop of copper tubing. Refrigerant has the unique ability to absorb and release heat energy rapidly. The condenser coil and compressor are typically mounted on a pad outside the home. The evaporator and blower (also called air handler) unit are located inside the home, usually in a basement, attic, or closet. The blower, which serves both the AC and the furnace, is attached to ducts which function as pathways to move air throughout the house. The system is controlled by the thermostat.
How It Works
When the thermostat signals that the home warmer than the set temperature, the AC system turns on. Outside, the compressor begins to compress the refrigerant into a high pressure gas. The compressor pumps the high pressure gas through a radiator-like condenser coil of copper (or sometimes aluminum) tubing and aluminum fins where a large fan transfers heat from the gas to the outdoors. This is all accomplished in the outdoor component of your air-conditioning equipment.
Next, the cooled, compressed refrigerant, now a liquid, is pumped into the house via the copper tubing, arriving at the evaporator coil (also radiator-like). There, under less pressure, it vaporizes from liquid to gas once again. A natural property of this change is that the refrigerant absorbs heat rapidly from the air being blown across the evaporator by the blower. The cooled air is circulated through the home via the ducts.
At the same time, humidity in the air condenses on the cold evaporator surface into liquid water, eventually dripping into a drain pan and down a drain. This way, the air is simultaneously cooled and dried, making the home more comfortable for the occupants.
The refrigerant gas then heads back outside to the compressor, where the cycle starts over again. Once the temperature in the home reaches the thermostat set-point, the system automatically turns off.