Abstract: A test door has wheels mounted thereon so that one person can easily roll the door to a doorway of a house to be installed. The test door has a fan permanently mounted thereon. The test door has panels or flaps, which slide against the doorway to seal the doorway against leaks. The door has mounted thereon a speed control device, and a tachometer to determine the speed of the fan. The door also has mounted thereon a differential pressure gauge so that the pressure difference from the inside to outside of the door can be measured. Therefore, to determine the amount of leakage of air from a house, the door is rolled to the doorway and quickly placed in the doorway by sliding the flaps out until they seal the doorway. Then by starting the fan, a determination is made as to the amount of air loss for different fan speeds and differential pressures.