It’s the height of the summer, and as the temperatures (and perhaps the humidity) outside continue to rise, the comfort of air-conditioning has become a necessity for many. If you’re in the market for a new air-conditioner here’s the latest scoop to help you and your family breathe easy. 

Cooling Type
When purchasing an air-conditioner, consider the size of the area you want to cool and your budget.

Central air-conditioning systems are often the most convenient because they cool the entire house at one time. The system works through the same air ducts your furnace uses to distribute heat but uses a condenser located outside the home, which pumps cold air into your ductwork inside. The air is then returned through different ducts to be cooled again. Central systems do require special installation with the ductwork, and a contractor can determine what size unit you need to effectively cool your home. The size unit considers insulation, the number, type and exposure of windows and doors and how the sun hits your house.

The unit and installation will run a few thousand dollars, depending on the size of the house and unit. If you are installing ductwork with the unit, the cost will be an additional $2,000-$4,000. In order to ensure you’re not losing all that cool air to your attic, the ducts in your attic should be heavily insulated while also being airtight.
 

Due to the complexity of the installation, central air-conditioning systems should be installed by professionals. Once installed, central units require only simple, routine maintenance.  The most important maintenance is to routinely replace or clean the filters. Clogged or dirty filters obstruct air flow and will significantly diminish the system’s efficiency. Discuss annual maintenance suggestions with your installer. Programmable thermostats can also help you save on utility bills. Many manufactures offer central air-conditioning units, including Rheem, Carrier, York, Trane and Lennox on the higher end, and Goodman, American Standard and Amana towards the lower price range.

Room air-conditioners, as the name implies, only cool one (or two small) rooms at a time. These units usually fit into a window. There are also units that can be permanently installed through an exterior wall, also called a built-in air-conditioner, which require custom wiring and installation. Both types of air-conditioners plug into a standard electrical outlet (unless permanently installed). Both types of air-conditioners work the same as a central unit except the cooling is done directly at the unit and isn’t forced through air ducts to different rooms. Instead, a room air-conditioner pulls hot air in from the outside and cools it by passing the air through a condenser and coils where a fan then blows the cooled air out into the room. 

It is important to buy the correct size unit with room air-conditioners. If the unit is too small, it won’t cool and will constantly run trying to cool the room. If the unit is too large, it will cool the air, but inefficiently. Units are measured in BTUs or British thermal units. A 5,000-BTU unit can cool up to 150 square feet. A 20,000 BTU unit can cool up an average of 1,100 square feet.

Before purchasing a room air-conditioner, consider the features you may find handy. Many models come equipped with a thermostat that automatically turns the unit on or off, depending on what temperature it is set at, much like your thermostat works in your house for heat. Others feature a timer that you can program for the unit to turn on before you wake up or arrive home. Be sure to take window measurements and note the type of window before you go out to purchase your air-conditioning unit. A room air-conditioner will cost you just a few hundred dollars. Several manufacturers, including Whirlpool, Frigidaire, GE, LG and Panasonic, offer room air-conditioners starting at $100 up to $400, depending on BTU. 

Energy Efficiency & Air Quality
All new air-conditioners will have an Energy Guide Label. This label will display the SEER (Seasonal Energy Efficiency Ratio) for central air-conditioners, and the EER (Energy Efficiency Ratio) for room air-conditioners. Look for a SEER rating of at least 9.7 going up to almost 17. EER ratings should be at least 9.0 in a mild climate to 10 or more in a hot climate.

When you are using your air-conditioner, you are recycling the same air over and over as it gets cooler. Because of this, indoor air quality becomes an issue, and if not filtered properly your indoor air can easily contain more allergens and pollens than outdoor air. An easy solution is to invest in a true HEPA filter for your air duct or blower that will filter the air before it enters the air ducts and your home. HEPA stands for High Efficiency Particulate Arrested Filter and was a standard that was defined for scientific "clean" rooms and laboratories. True HEPA filters will capture 99.97 percent of all particles that are as small as 0.3 microns. The price will be high, about $80, but is worth it when it comes to your home’s air quality.

Helpful Links
The following links might come in handy when selecting and installing a new air-conditioning unit.

American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE)
1791 Tullie Circle, N.E.
Atlanta, GA 30329
(404) 636-8400
Fax: (404) 321-5478
www.ashrae.org
ASHRAE is organized solely for the purpose of advancing the arts and science of heating, ventilation, air conditioning, and refrigeration for the public's benefit through research, standards writing, continuing education, and publications.

Air Conditioning Contractors of America (ACCA)
1513 16th Street NW
Washington, DC 20036
(202) 483-9370
Fax: (202) 234-4721
www.acca.org
The Air Conditioning Contractors of America is the most active and widely recognized organization representing contractors in the heating, ventilation, air conditioning, and refrigeration (HVACR) industry.

EnergyStar Program
1-888-STAR-YES
e-mail: info@energystar.gov
www.energystar.gov
ENERGY STAR-labeled products, including heating and cooling equipment, use less energy than other products and save you money on utility bills. These products are made by all major manufacturers and are available at stores everywhere.