Need A New HVAC System? Do A Load Calculation First

February 7, 2013

When you’re in the process of selecting a new heating or cooling system, the first step should be a load calculation. It helps you learn your home’s strengths and weaknesses with regard to its energy efficiency. When you know where the inefficiencies lie, you can take steps to improve them, which can make a difference in the size of equipment you need.

When HVAC contractors calculate the conditioning load in your home, they use a tool called Manual J. It takes into account these factors:

Cubic footage you need to condition;
Insulation levels in the walls and attic;
Windows, their efficiency and exposure to the sun;
Floor plan of your home;
Air infiltration rates;
Heat-producing appliances under roof;
Preferred temperatures;
Age and number of family members; and
Outdoor landscaping factors.

After the HVAC representative takes you through this calculation, you may be able to lower the load by increasing insulation, improving your windows, sealing air leaks or taking other energy-saving steps. Lowering the load may result in being able to choose a smaller system, which helps you save money initially and over the life of the system. Increasing the insulation and sealing air leaks are inexpensive solutions that will reduce conditioning bills.Choosing an HVAC system without a load calculation using Manual J can result in installing equipment that’s too large. If you go by the size of your existing equipment, you could be making a common mistake. Older homes are not as energy efficient as newer homes, and they often require larger systems. Systems that are too large short-cycle, which means that they run for short periods more frequently. This adds a lot of wear and tear to the equipment, provides uneven heating or cooling, and wastes energy.Your home may not stay as comfortable with a system that runs briefly, especially in the summer because the humidity will be higher. Rooms won’t stay as warm in the winter with systems that are too large because the furnace won’t run long enough to heat the air thoroughly.If you’d like to learn more about a load calculation for your Western Colorado home, please contact us at Climate Control Company. We’ve provided quality HVAC services for western Colorado since 1956.

Our goal is to help educate our customers in Aspen, Vail and the surrounding Western slope communities in Colorado about energy and home comfort issues (specific to HVAC systems). For more information about load calculations and other HVAC topics, please visit our website.

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