FAQ Category: Blower Door

The maximum watt draw is 1000 watts.  It is best to oversize a supply source slightly, so 1200 watts will work best.

Yes, there is.  Channel B of the DG-700 is actually measuring a pressure at the flow sensor of the fan and converting the pressure to flow based on the Devise and Configuration settings on the gauge.  Appendix B of the blower door manual has Flow Conversion Charts that allow you to determine what fan pressure the gauge was reading during the test.  Here is an example that will demonstrate the process.  Let’s say you recorded a reading of 3736 CFM and had the DG-700 configuration set to Open.  On your way home you are thinking that the home should have been much tighter and you realize that you actually had Ring A installed on the blower door fan.  Here is the process to find the correct reading:

• Follow down the Open Fan column until you reach 3736 CFM
• Follow across to the Fan Pressure column and you will see that you were measuring a fan pressure of 60 Pascals during the test
• Follow across to the Ring A column and see that 1400 CFM is the correct reading

The formula is (CFM50 X 60) ÷ the volume of the house.

So if your blower door CFM50 reading is 1000 CFM and house is 30’ x 40’ x 8’ tall, the ACH = (1000 x 60) ÷ (30 x 40 x 8) = 6.25 ACH

Yes. Here are the options for washing your blower door panel.

1. If the coating on the back of the panel is not flaking off and is not damaged, then it can put it in the washing machine, cold water cycle, on a gentle cycle and with a little bit of gentle detergent.
2. If the coating on the back of the panel is flaking off or is damaged at all, then it’ll need to be hand washed in cold water with a little bit of gentle detergent.

In either case the panel should never be put in the dryer. It should always be air dried.

Will using a transformer in this situation compromise the durability or accuracy of the Model 3 blower door?

Assuming that the transformer will provide a “clean” power source (no large voltage spikes), and will provide 110V 60 Hz power (not 50 Hz), there should be no durability issues. Calibration is not affected by this issue.