To handle the Peachtree City summer heat and winter chill efficiently, your cooling and heating equipment must be correctly sized. This requires your technician to accurately calculate your home’s heating and cooling loads. A “load” is the amount of heat energy that has to be removed from or added to a space to keep it at a comfortable temperature. There are three types of loads.

Design Load

This refers to the home’s heating and cooling loads during the weather conditions the heating and cooling system was designed for. HVAC technicians calculate these loads by following the Air Conditioning Contractor of America’s (ACCA’s) Manual J. This involves collecting information about the house and running that information through a computer program. Manual J calculations are based on specific weather conditions, so while they’re useful for sizing a system, the actual loads vary depending on the current weather.

Extreme Load

Needless to say, our weather doesn’t stick to the ACCA’s guidelines, so your technician considers other factors. Extreme load is what your home experiences under extreme weather conditions, meaning the hottest summer afternoons and the coldest winter nights your location sees. The temperature extremes in Peachtree City influence the capacity your system should have, but don’t define it. Sizing an air conditioner or furnace based on these extremes would result in an oversized system, which leads to inefficiency and performance problems.

Part Load

This is the load your air conditioner and furnace will deal with most often. Most of the time, the actual temperatures are milder than the design and extreme temperatures. This reduces the demand on the system, but it can cause problems if you have a fixed-capacity system. If you have a 2.5 ton (60,000 BTU) system, but the cooling load that day is only 1.5 tons (18,000 BTU), your air conditioner may run in short blasts, known as short cycling. This causes temperature swings and poor humidity control. Complexities such as these are why professional sizing is so important.

To learn more about calculating heating and cooling loads, contact us at Powers Heating & Air in the Peachtree City area.

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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