If you are reading this, it is likely you clicked a link from our email series explaining energy modeling and it's benefits. Specifically, the email "How does Energy modeling save energy?"

In this case, R-50 insulation used more energy than R-25 in a building in Denver, Colorado.

The main issue was that the R-25 building did not need heating or cooling for most hours when the outdoor air temperature was between 50 and 67 degrees. The building with the extra insulation, on the other hand, did not need heating or cooling between 50 and 58 degrees (the sweet spot was half the size when adding the extra insulation).

In this example, R-50 used MORE energy than R-25. Here's why:

The extra insulation did save energy during many hours of the year, especially when the temperature was below 30 degrees fahrenheit.

HOWEVER, the local climate had hundreds of hours where the temperature was between 58 and 67. This meant that the cooling equipment had to run for extra hours BECAUSE of the extra insulation was effectively trapping heat inside the building during those hours.

I thought of a very simple test. I magically moved the building to a cold climate (I live in a cold climate and I know how important insulation is).To “magically” move a building in an energy model, you just need to switch the weather file. I chose the coldest place I could find within my weather files and that was International Falls, Minnesota.

I ran the simulation and showed a substantial savings for the R-50 insulation, as one would expect in a really cold climate.

Once you learn more about building thermodynamics, you quickly learn that insulation is only a small portion of the details that can be altered. Energy modeling allows you to alter thousands of details to determine what choices are the best for your building.