In article ,
Anthony Matonak wrote:

You might be able to do almost as well using a non-contact thermometer.
Go out on a cold night and scan the likely places, like around windows
and doors. It's slower but works on the same principle.

I've done that from the inside, spotting cold spots that needed more
insulation. It works and is cheap

Free men own guns - www(dot)geocities(dot)com/CapitolHill/5357/