I have one of those $250 gizmos that let you use your smart phone as an IR camera. Here are a few things I’ve learned:
Best time for an outdoor scan is 5AM. The house has had plenty of time to lose any heat from the sun. Even with a 50-degree ambient, there’s plenty of contrast for the camera to see. At 5AM, there’s less chance of your confusing visible light with the IR scan.
Outdoor scans need to be complimented by indoor scans. It’s best to do indoor scans just before the furnace kicks on. Maybe get a piece of chalk (or can of spray paint) and mark bad areas as you scan
Example: While outdoor scans seemed to say my roof was well insulated, the indoor scans identified some places where attic insulation was missing. Likewise, I can ‘see’ where the walls have missing insulation.
Some surprises for me:
1) The carport wall is simply pouring heat into the carport. I guess the builder didn’t think insulation was needed there.
Some of the carport difference might simply be caused by less air circulation. Makes me wonder if a row of shrubbery is ‘energy efficient’ 🙂
2) Fans to keep air moving in the house have a huge effect on heat distribution.
3) Some places I had thought I had sealed / insulated still need work. For some reason, the hinge side of doors is a big heat loser.
Not every question has been answered. My ‘outside’ scan seemed to show a lot of heat escaping through the crawl space, yet the indoor scans didn’t show any obvious weak spots. (BTW, airflow through the crawl space is restricted, but not completely closed off.) Perhaps the footings are drawing their heat from the ground itself.
4) The new, double-pane ‘energy-star’ windows still bleed heat. Makes me shudder at what the old windows lost. I think I’ll suppliment the windows with plastic film (‘poor mans’ storm windows’) and heavy drapes.
