certain rooms just feel cooler than they should, like the heat is slipping out through some secret escape hatch or something, I checked for drafts around the doors and windows, added weatherstripping, even did the old candlestick test along the baseboards but still, there are spots where you I feel the chill creeping in. I dont know if it could be the attic insulation. How can I do a proper deep dive into tracking down heat loss? do I use thermal cameras, blower door tests, or just the good old fashioned detective work? or maybe I should just bring in the pros but that's billing for me