Central air conditioner systems offer an excellent method of keeping one’s entire home cool. Most of these systems include an outdoor unit that disperses the heat removed from the home as well as an indoor air handler to move air through the cooling coils ducts and disperse it into the home.
Physics teaches that compressing a gas to a liquid releases heat while allowing a liquid to expand to a gas absorbs heat or creates cooling. The refrigerant is a liquid with a very low boiling point. It is converted from a gas to a liquid and back to a gas in a in a closed system to provide cooling. Most air conditioning systems use this principle to provide cooling for homes. In addition passing air through cooling coils causes moisture to condense lowering the humidity and increasing comfort levels for occupants of the home.
The external unit of the central air conditioning system is the location of the compressor. In addition the unit includes a large powerful fan and heat exchanger coils. These coils serve to disperse the heat removed from the home. Large commercial systems sometimes use cooling towers with water to provide cooling through evaporation. With geothermal systems refrigerant passes through lines buried in the earth to disperse heat from the home in the earth at a level that remains constant all year long.
Inside the home the air handler includes a squirrel cage blower and cooling coils. The blower creates a vacuum in the air return vents to remove air from inside the house and places positive pressure on the ducts to move the treated air throughout the various rooms. Return air passes through a filter to remove particulate matter. The blower forces the warmer room air through the cooling coils. The refrigerant absorbs heat so the air exits the cooling coils with a temperature drop.
The ducts are the distribution system used in most central systems. The number of registers or duct openings in each room is determined by the size of the room being cooled. Mini-split systems are a popular option in providing central cooling for older homes without ductwork already in place. Instead of pumping cooled air through ducts refrigerant is piped to several smaller air handlers to provide cooling different areas of the home using one centralized exterior compressor unit.
In tropical areas humidity is often just as great a problem as is the heat. High humidity interferes with the human body’s natural cooling system. Air conditioning is an effective way of reducing humidity. As air temperatures drop moisture condenses. In the air conditioning unit the coldest spot is on the cooling coils. Systems are designed to allow water to collect on the coils and drip to a tray where it drains away. In a room where the humidity is lowered by air conditioning your body perspires and the perspiration evaporates to keep you at a constant internal core temperature. During the annual maintenance of the system the technician ensures the drain allows free flow of the collected water.
Regardless of the type of AC system installed in a home it is essential that owners schedule regular maintenance of the system. New high efficiency systems loose 5-10% efficiency each year they are not serviced. The losses do not just end with consuming more energy. A system is more likely to fail if it is not maintained on a regular basis.
The principles of physics that allow central air conditioning to transfer heat from inside the home to the outside in order to produce cooling may seem magical but they work very well. The system uses mechanical parts both inside and outside the home to produce cooling. The duct system transports the treated air. Maintain the unit regularly for greater energy efficiency.