Before you get too far into the process of selecting a central A/C system, ask your HVAC contractor to conduct a load calculation first. This calculation involves using Manual J software and is the only way you and the contractor will know the exact size for your new cooling system.

Central heating and air systems are sized by tonnage in half ton increments generally from 1.5 to 5 tons.  Basing your decision on the size of your current equipment could be misleading, since the size you need has a direct relationship between your home’s size and energy efficiency. Changes in your homes insulation can change the tonnage you need to satisfy your home comfort.  Energy upgrades like installing double pane windows or insulated siding can reduce the tonnage you need. If you or a previous owner has changed only part of the system in the past, you could be selecting a system that’s too large or too small.  Professionals like Powers Heating and Air can help you make the right decision.

Why It’s So Important

The wrong size adds to your cooling costs, reduces comfort and can shorten the life of the new system. Of the two, it’s worse to select too large a system, since it will run in brief spurts that drive up energy costs and significantly reduce the dehumidification of your home in the South. When a central A/C system first starts, it uses much more energy than anytime during its running cycle.  Longer run time means you save money and feel more comfortable.  Also, frequent starts wear the parts faster, increasing maintenance and repair costs.

What’s Involved

Manual J software is widely used by HVAC contractors and requires inputs about your home that affect its cooling load. The analysis requires a great deal of detail about:

• Factors that affect its energy efficiency, like the number of windows, their orientation and quality, along with insulation and air infiltration levels.
• The layout of your home, its solar orientation and cubic footage.
• Heat-producing activities, like cooking and lighting types.
• Your family’s characteristics and preferred temperatures.

During the process, you may learn that you could reduce the cooling load by adding insulation, sealing air leaks, sealing the ductwork, which can reduce the size system you need; and which saves money initially and over its lifetime.

Powers Heating and Air provides free estimates with a professional comfort advisor who educates you as well as properly sizes the home while he meeting with you.  We have been providing top-notch HVAC services for local homeowners since 1979 in Newnan, Senoia, Sharpsburg, Peachtree City, Tyrone, Fayetteville and the surrounding areas.

Our goal is to help educate our customers in Peachtree City, Georgia and surrounding areas about energy and home comfort issues (specific to HVAC systems).

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