Retrotec Blower Door - Manual (Page 33)

Page 33 of 87
©Retrotec Inc. 2015
Install the panel in a doorway where the door can be closed with the door fan panel in place, then measure the
leakage. This is the Test Panel Leakage + Door Leakage.
Now, tape over the door so it does not leak at all and re-measure the leakage. This is the Test Panel Leakage.
Subtract 2 from 1. This is the Door Leakage.
Subtract #2 and add #3 to your test result.
Modular Panels:
1000 CFM at 50 Pa, no attention needs to be paid to the door panel leakage. If the flow rate is under that you might
want to measure the panel tightness compared to the door tightness and subtract any excess from the readings. Or,
if the panel is tighter than the door, you will have to add it.
Example; 500 CFM at 50 Pa for the enclosure. Door is closed over top of the panel with the red tube in the gap and
leakage measured at 50 Pa of 140 CFM. The door is then taped shut to measure panel leakage which is 80 CFM at 50
Pa. The Door thus leaks 140-80=60 CFM. Correction to test result is then: 500-80+60= 480 CFM.
Aluminum Frame and Cloth:
220 CFM at 50 Pa, no attention needs to be paid to the door panel leakage.
Aluminum Frame with upgraded snap together corners and Cloth:
70 CFM at 50 Pa, no attention needs to be paid to the door panel leakage. If the flow rate is under that you should
measure the panel tightness compared to the door tightness and subtract any excess from the readings. Or, if the
panel is tighter than the door, you will have to add it which is more common and shown in the following example:
Example: 50 CFM at 50 Pa for the enclosure. Door is closed over top of the panel with the red tube in the gap and
leakage measured at 50 Pa of 8 CFM. The door is then taped shut to measure panel leakage which is 3 CFM at 50 Pa.
The Door then leaks 8-3= 5 CFM. Correction to test result is thus: 50-3+5= 52 CFM.
These tests are rarely done but testers should learn how leaky their panels are in advance of any test they may do.
Retrotec has performed this test in nuclear power plants where every part of the test needed to be documented
including panel leaks. Learning how much your panels leak will be a useful tool to determine how they might be
affecting your results. For example, when Modular Panels are used to measure flows well in excess of 2000 CFM,
the panel leakage is irrelevant, but in tight rooms it could make the difference between pass or fail. One has to
determine then if the door leakage may be a major part of the total and cannot just be deducted. Similarly, if you
are using the new tight Aluminum Frame with square snap together corners, your readings might be low.