How
Blower Doors Work
A blower door is a powerful fan that mounts into the frame
of an exterior door. The fan pulls air out of the house, lowering the
air pressure inside. The higher outside air pressure then flows in through
all unsealed cracks and openings. The auditors may use a smoke pencil
to detect air leaks. These tests determine the air infiltration rate of
a building.
Blower doors consist of a frame and flexible panel that
you can place in a doorway, a variable-speed fan, a pressure gauge to
measure the pressure differences inside and outside the home, and an airflow
manometer and hoses for measuring airflow.
Infrared scanning allows energy auditors to check the effectiveness
of insulation in a building's construction.
Preparing
for a Thermographic Inspection
To prepare for an interior thermal scan, the homeowner should
take steps to ensure an accurate result. This may include moving furniture
away from exterior walls and removing drapes. The most accurate thermographic
images usually occur when there is a large temperature difference (at
least 20°F [14°C]) between inside and outside air temperatures.
In northern states, thermographic scans are generally done in the winter.
In southern states, however, scans are usually conducted during warm weather
with the air conditioner on. |