Cfm50 is the airflow measured in cubic feet per minute from the blower door fan needed to create a change in building pressure of 50 pascals.
What is a good blower door test result.
Blower door test results can determine the airtightness of the building and can be presented in a number of different formats.
Understanding blower door test results.
Once he is done with his walk through your auditor will begin the test.
A blower door is a machine used to measure the airtightness of buildings.
1 a calibrated variable speed fan capable of inducing a range of airflows sufficient to.
If your home is 2000 square feet a blower door number of 2000 cfm50 is decent.
It s a linear scale so 2000 is twice as bad as 1000.
During this test a calibrated fan is installed in an otherwise sealed door or window while all the other openings to the exterior are closed.
Simply put a blower door is a diagnostic tool used to measure how much air infiltration air leakage occurs in a house.
It can also be used to measure airflow between building zones to test ductwork airtightness and to help physically locate air leakage sites in the building envelope.
This tells you how often the air in your house would be entirely replaced if the fan ran nonstop.
Last year we built an energy star home for a customer and we used a blower door test to evaluate the houses air infiltration performance.
Better consistency and reproducibility occur at higher pressures.
Here are some things to know.
A good rule of thumb is that your home should have a blower door number less than or equal to its square footage.
In the report you ll see a reading for the ach an acronym that stands for air changes per hour.
He will systematically move about your home setting up the house for the test.
The following will help you conduct your.
Air flow at 50 pascals is the preferred value for blower door testing the amount of airflow measured in cubic feet per minute cfm for a.
Higher numbers are worse.
Blower door test results are standardized for an air pressure difference of 50 pa.
The auditor will set up his blower door in an outer door facing outward to depressurize your home in most cases.
There are three primary components to a blower door.
What does the blower door number mean.
Blower door tests are performed by trained and certified energy auditors but a homeowner can conduct a mini test to help pinpoint leaky areas of the home.
The test requires a few parameters be set to yield accurate results.
You ll receive a report at the end of the test that will let you see how airtight your home is.
What is a good blower door test result.