About Damien

Damien McCusker, Manager of Arpi's residential service division, has been working in the HVAC industry for 18 years and has hands-on experience in new home installations, furnace and air conditioner replacements, sales and residential service. He spends most of his spare time sharing his passion for soccer with his kids and enjoys watching them at soccer practice and games.

You are here

Two HVAC Sizing Methods Your Contractor Should Employ


Two HVAC Sizing Methods Your Contractor Should EmployMost people don’t realize that HVAC sizing methods have a big impact on the energy efficiency and longevity of furnaces, air conditioners and heat pumps. Both the size of the equipment and the ductwork need careful evaluation before you decide on the system for your home.

The heating and cooling load of your home includes these factors:

  • Cubic area you need to condition;
  • Insulation levels;
  • Windows, their efficiency and solar orientation;
  • Air infiltration rates;
  • Orientation of your home to the sun;
  • Floor plan of the home;
  • Number of household members and their ages;
  • Preferred temperatures; and
  • Landscaping factors.

These factors drive the size of the system you need and lead the HVAC contractor to the size of system for your home using formulas developed by the Canadian Standards Association (CSA) called CAN/CSA-F280-M90. The exercise gives you an opportunity to see how improving the energy efficiency of your home could change the size of the system you need.

The next step is to determine the ductwork design and capacity using the software and the results of the analysis for system sizing. If your floor plan design includes rooms that are appreciably different from each other, the size of the ductwork will vary throughout the home.

Both of these HVAC sizing methods assure you that the equipment in your home matches the conditioning load. Systems that are too large raise your energy bills and cause premature problems. Heating and cooling systems that are too small won’t be able to satisfy the conditioning requirements during weather extremes.

An air conditioner or heat pump that’s too big won’t remove as much humidity in the summer and will start and stop more often. Frequent starts drive up your electricity bill and increase the work load on the parts. In the winter, a heating system that’s oversized will heat the air too quickly and the solid objects in your home won’t retain as much heat forcing the system to restart more quickly.

If you would like more information on HVAC sizing methods, contact Arpi’s Industries, Ltd. We’ve provided HVAC services in the Calgary area since 1963.

Our goal is to help educate our customers in Calgary, Alberta about energy and home comfort issues (specific to HVAC systems). For more information about equipment sizing methods and other HVAC topics, download our free Home Comfort Resource guide.

Image courtesy of Shutterstock

Blog Categories: