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Blower Door testing
Using diagnostic tools and interpretting the results can often be counter
intuitive.
Using a blower door is basic, and easy to understand.
The home is put into "winter time"
conditions, all windows exterior doors shut. The furnace
is turned off, the fireplace made safe. A collapsible door is
installed in one of the exterior doors to the home, with a fan in the
temporary door.
Now the fan is set to push air out of
the home. (Depressurize)
Since the home has no windows or doors open, the pressure in
the house drops slightly.
We slowly increase the speed of the fan untill we depressurize the
home to a specific number, -50 pascals.
Once we are able to hold and maintain
the -50 pascals we know that the amount of air
being pushed out by the fan, is coming into the home through
infiltration. At this point we can take a reading from one of our
instruments that tells us exactly how much air the fan is pushing !
In this image, the house is at -54.3 pascals and the fan is pushing
2,964 cubic feet every minute !
While the blower door is operating, we
would try to find the largest infiltration areas and determine just
how much air is being introduced to the home.
This can be done by zonal diagnostics,
using a second manomitor to see if a room is more connected to the
home then outside. We can use a smoke pencil, thermal imaging, even our hands.
In a typical home we would find that the
high hats, say all 20, are leaking considerably.
We might also find that the pull down stairs, plumbing and wiring
chases (in interior walls) add considerably to that number.
If your home feels drafty, or any
problems listed in our "Common issues"
page,
call us and stop wasting valuable energy !
rec-hers@optonline.net
Residential Energy Conservation
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3771 Nesconset Hwy |
Suite 101A |
S. Setauket NY 11720
631-751-7911
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