The Drift on Cooling Systems!

Cooling your home involves air being circulated over a surface which has been maintained at a lower temperature. This surface may be in the space to be cooled or at some remote location with the air being ducted to and from the space. Usually water or a refrigerant is the cooling medium. There are three basic cooling technologies you may choose to use in your dream home. They are air conditioning, heat pumps and evaporative cooling.

Air conditioning

An air conditioner is basically a refrigerator without the insulated box. It uses the evaporation of a refrigerant, like Freon, to provide cooling. The mechanics of the Freon evaporation cycle are the same in a refrigerator as in an air conditioner. Depending on your needs, you may choose either a room air conditioner or a central air conditioning system.

• Room Air Conditioner - These units cool individual rooms as opposed to an entire house, providing cooling only where it is needed. While individually they are less energy efficient than a central air system, overall they may be less expensive to operate because they only cool where it is needed. The EPA requires that new room air conditioners have an EER (Energy Efficiency Ratio) of 8.5 or greater. If you live in a mild climate, it is recommended you select a unit with an EER of at least 9.0. If you live in a hot climate, a unit with an EER of over 10 is recommended.
• Central Air Conditioner - A Central Air system circulates cool air through a system of supply and return ducts. Supply ducts and registers carry cooled air from your air conditioner throughout your home. The air then flows back to the central unit through return ducts and registers. The minimum EPA standards for a central air conditioner are a SEER (Seasonal Energy Efficiency Ratio) of 12. However, there are many excellent systems available with SEERs of nearly 17. The higher the SEER, the greater your energy savings will be.

Heat Pumps

Heat pumps can work to either heat your home or cool it. When they are in the cool mode, heat pumps move heat from your cool house into the warm outdoors. Because they move heat rather than generate heat, heat pumps can provide up to 4 times the amount of energy they consume. There are two types of heat pumps - air source and geothermal heat pumps.

• Air Source Heat Pump - In the cooling mode, the heat pump takes heat from inside your home and dumps it outside.
• Geothermal Heat Pumps - These heat pumps use the constant temperature of the earth as the exchange medium instead of the outside air temperature. While many parts of the country experience seasonal temperature extremes-from scorching heat in the summer to sub-zero cold in the winter-a few feet below the earth's surface the ground remains at a relatively constant temperature. Depending on latitude, ground temperatures range from 45°F (7°C) to 75°F (21°C). Like a cave, this ground temperature is warmer than the air above it during the winter and cooler than the air in the summer. The Geothermal Heat Pump takes advantage of this by exchanging heat with the earth through a ground cold heat exchanger. Even though the installation price of a geothermal system can be several times that of an air-source system of the same capacity, the additional costs are returned to you in energy savings in 5-10 years. System life is estimated at 25 years for the inside components and 50+ years for the ground loop.

Evaporative Cooling

An evaporative cooler (also known as a swamp cooler) produces effective cooling by combining a natural process - water evaporation - with a simple, reliable air-moving system. Fresh outside air is pulled through moist pads where it is cooled by evaporation and circulated through your home by a large blower. As this happens, the temperature of the outside air can be lowered as much as 30 degrees. Evaporative coolers work well when the outside air is dry and desert-like. As the humidity increases, however, the ability for them to cool the air effectively decreases. Since water is continually lost through evaporation, a swamp cooler can use between 3 to 15 gallons of water a day. For evaporative cooling to work properly, the cooled outside air must be allowed to escape. By choosing which doors or windows in your home you leave open, you can help direct the flow of cooled air to areas where it is needed. The type of cooling system right for your dream home is based on many factors - budget, your area's weather and the size of your home. Talk with your architect or designer on what is the right system for you and your family.