Why do a heat load?

A heat load calculation is a great way to tinker with building envelope parameters in order to select HVAC equipment, to improve efficiency, and to help choose cost effective installations. Click here to view my blog explaining heat loads.

The heating and cooling loads are the amount of heat energy that would need to be added or removed to maintain the temperature in an acceptable range.

A high performance house needs to:

  1. be built with an airtightness strategy,
  2. be well insulated,
  3. have adequate shading,
  4. have a ventilation system.

Only once these four items have been addressed will a heat load outcome be close to being accurate.

Here’s a snapshot of our own GOrate Delta heat load calculator.


A big thank you to the guys at Constructon Instruction  for their guidance via training, phone calls and emails.

Thanks Mark LaLiberte for telling me to “…keep it simple. Don’t overcomplicate it. Trust the science and the math.”

Thanks to Justin Wilson for impressing on me the importance of slab edge insulation and warning me about  the computer modelling concept of GIGO (Garbage In = Garbage Out).

Thank you to Gord Cooke for all the techincal data and for generouly providing his own software calculations from Building Knowledge Canada for comparitive purposes.