A blower door test determine's a home's airtightness. Here is how it works: 👉A blower door is a essentially a powerful fan mounted into the frame of an exterior doorway in your home. 👉The fan pulls air out of the house, lowering the air pressure inside. 👉The higher outside air pressure then flows in through all your cracks, gaps, wiring penetrations etc You should also use an infrared camera to look at the walls, ceilings, and floors, to find specific locations where insulation is missing and