Blower Door Test Formula

Simply put a blower door is a diagnostic tool used to measure how much air infiltration air leakage occurs in a house.

Blower door test formula.

What is a blower door test. Blower door tests are becoming part of many state and provincial mandatory building codes the new bc energy step code in british columbia canada is one example. 1 a calibrated variable speed fan capable of inducing a range of airflows sufficient to. 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.

Cubic feet per minute of air leakage at 50 pascals of pressure rough in. And the indicated qn that is the number that the test has to be less than or equal to. Leakage type could be indicated as default leakage simply taking no credit for tighter ducts if not default than it. A blower door is used to measure the tightness of a building and is often discussed in terms of an ach50 number that many will simply refer to as the blower door.

Adjust for temperature using charts not required if delta t less than 30f adjust for elevation using a formula not required if altitude less than 5 000 ft tec quick guide. Blower door sample calculation air infiltration. After installation of the complete air distribution system but before installation of insulation and sheet rock. Once the energy auditor arrives it takes between 10 and 20 minutes to install the blower door inside an existing door frame an additional 10 to 15 minutes to prep the house for the test and.

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. Air leakage testing calculator blower door test cfm 50. 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. Understanding blower door test results.

A blower door test is often an essential part of a home audit we don t know for sure just yet if it will be part of the free home energy audits promised by the canadian liberal government in oct 2019. A blower door is a machine used to measure the airtightness of buildings. Blower door test results can determine the airtightness of the building and can be presented in a number of different formats. Here are some ways to calculate cfm10.

An older blower door manual shows that the formula for equivalent leakage area 0 2939 x cfm10. There are three primary components to a blower door. This photo is of a blower door test we performed at my own house using a retrotec blower door. Also attached is appendix d of the old manual that shows some test results and those results graphed on log log graph paper.