Letters Air-Sealing Diagnostics I just finished reading Bruce Torrey's article on sealing leaky attics (2/08), and have a question. In our area, insulation quality is historically abysmal. Are the diagnostic tools Bruce uses — the blower door and infrared camera — entirely necessary for attic sealing? Or in houses where the insulation quality is known to be poor, could builders use some generally prescriptive measures initially, then use these tools for a more nuanced assessment of the problem at a later date? Jesse Smith Yardley, Pa. Bruce Torrey responds: Infrared scans completed on thousands of buildings demonstrate one consistent fact:
