Understanding Your Home Air Conditioning Unit

Know when to buy, upgrade and overhaul a home air conditioner, including AC basics, selection, and sizing the system.


| June/July 1993



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Don't sweat and suffer all summer long. Let your air conditioner keep you cool and comfortable.


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Approximately 57 million U.S. households (roughly 60%) have air conditioners, with an energy consumption equivalent to the output of seven large coal power plants, and at a cost to homeowners of $9.8 billion. That amount of electric energy results in the release of about 100 million tons of carbon dioxide per year, or a little under two tons per year on average for every home with air-conditioning. Furthermore, air conditioner use in the United States has increased more than 20% since 1984. Seventy-five percent of new homes are being outfitted with central air-conditioning systems, reports Air Conditioning, Heating, and Refrigeration News, including over half the homes in the Northeast. A switch to high-efficiency air conditioners and measures to reduce cooling loads in homes can reduce this energy use by 20-50%

Air-Conditioning Basics  

Air-conditioning, or cooling, is more complicated than heating. Instead of using energy to create heat, air conditioners use energy to take heat away. The most common air-conditioning system uses a compressor cycle (similar to the one used by your refrigerator) to transfer heat from your house to the outdoors.

How is this done? A compressor is filled with a special fluid called a refrigerant (usually HCFC 22, one of the environmentally notorious chlorofluorocarbons). One of the chemical's properties is that it can change back and forth between liquid and gas. As it changes, it absorbs or releases heat. Thus, it is used to "carry" heat from one place to another, such as from the inside of a refrigerator to the outside, or-using an air conditioner from the inside of a house to the outside. Simple, right? Well, no. And the process gets quite a bit more complicated with all the controls and valves involved.

But its effect is quite remarkable. An air conditioner takes heat from a cooler place and dumps it in a warmer place, seemingly working against the laws of physics. What drives the process, of course, is electricity-quite a lot of it, in fact.

Types of Air Conditioners  

There are three common types of air conditioners: separate room air conditioners, central air conditioners, and electric heat pumps. Both central and room units work the same way, with the compressor located outside. Room air conditioners are sized to cool just that one room, so a number of them may be required for a whole house. Central air conditioners are designed to cool the entire house. The large compressor unit is located outside, and the inside coils cool air that is distributed throughout the house via ducts.

Often, the same duct system is used for forced, warm air heating systems and central air conditioners. Heat pumps are like central air conditioners, except that the cycle can be reversed and used for heating during the winter months. In addition to these common types of air conditioners, there are several other types used very successfully in certain parts of the country. Evaporative coolers are practical in very dry areas, such as the Southwest.

alastairarchie
5/16/2014 10:59:19 PM

Too much concentration on negative sides of the use of technology would cost nothing but harm to the way of thinking of public. Americans already doing great jobs by http://creightonlaircey.net/air-conditioner-repair-augusta/ and reviving them for longevity of their life-span. It's saving a great on energy consumption.


martha
5/8/2014 11:14:03 PM

Air Conditioners are the one off the most usable home appliances. Understanding about these machines means that you can http://airconditioner-notcooling.com/ without hiring an Ac technician. These are the most important parts of an air conditioner. Compressor Compressor takes suck the hot air and blow it out using the outer fan. While the condensation converts hot air in the cold this process can be reverse to. Outer In the split units an outer is connected through the copper pipe. While in the window ac it attach with the same panel. Filters Filters are used to clean the air . thermostat For the temperature. Now a days digital thermostats are commonly in.






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