Photo Source:
Summerhill |
- Measures how quickly the air in
the home is replaced by outside air
- Expressed as air changes per
hour (ACH)
- A blower door is used to perform
the test
The lower the air changes the
better. It means that heated indoor air will remain in the home
longer during the winter, and cooler air will remain in the home
longer during the summer. However, moisture and pollutants may also
remain in the home longer so it is important to control the quality
of the indoor air.
How the blower door
works:
- Air from the house is pushed
outside with a fan (depressurization), or outside air is pushed
into the home(pressurization)
- The fan maintains the air
pressure in the home at a certain pressure difference between
inside and outside (50 pascals)
- The volume of the air the fan
has to move to maintain the pressure lets us know how much air is
entering the home through leaks and cracks
- With this information we can
determine how air tight the home is