Replies

1. Expert Member
   Akos | Jun 17, 2019 10:32am | #1

   I've used this one before. Takes a bit to figure out and setup up.

   https://www.nrcan.gc.ca/homes/learn-about-professional-opportunities/tools-industry-professionals/20596

2. 
   Jon_R | Jun 17, 2019 10:40am | #2

   +1 on using some software to calculate payback on any energy saving feature. Possibly BEopt.

3. Expert Member
   Dana Dorsett | Jun 17, 2019 11:44am | #3

   >"I am building a home and realizing there are a lot of windows. "

   The time to start this type of analysis is while designing the house, not while it's being built. Being selective about location & size, solar gains & U-factors of the windows can make or break it.

   But it's silly to take the position " I was considering exterior insulation but have been reading here that it may not be worthwhile if a big percentage of heat loss is out the windows. " By that kind of thinking you might as well live in a tent. The amount of heat loss per square foot for the walls is the same, independent of how much glass is installed. If it's "...worthwhile..." on a house that has very little glazed area it's also "...worthwhile..." for a house with more glazed area. The total amount of exterior insulation and it's cost scales with the total area being insulated.

4. 
   Peter Yost | Jun 18, 2019 10:33am | #4

   BEopt is a great free, online energy modeling program. But it is a significant time investment to learn.

   One tool that can help with the impact of glazing performance is the Efficient Windows Collaborative window selection tool: https://www.efficientwindows.org/new_selection1.php.

   Peter

1. 
   ethan_TFGStudio | Oct 30, 2023 02:15pm | #5

   BEOpt works well but you can no longer create ERI data to prove energy code compliance.