Blower Door Simulator

Test house

Conditioned floor area2,400 ft²

Average ceiling height8.0 ft

Enclosure volume19,200 ft³

Fan in the door6,100 CFM open

Wind

Randomized houses run 1,400 to 4,500 ft² with 8 to 12 ft ceilings. Tightness stays hidden until you record a result.

1 · Prepare the enclosure

Close all exterior windows and doorsLatched, not just pushed to Open all interior doorsClosets, mechanical room, and any attic access inside the boundary Turn off the air handler and every exhaust fan Shut down combustion appliancesNo active burn, nothing drafting Close the fireplace damper, confirm no ash or embers Dryer, range hood, and bath dampers closed but unsealedIntentional openings stay untaped for an ACH50 result

0 of 6 complete.

2 · Set the range ring on the fan

3 · Run the hoses

Hoses:

Blue

Red

Yellow

Green

Blue

Red

Yellow

Green

Outdoors,
in the grass

Fan tap

Channel A ⊕ · blueNot set

Channel A ⊖ · redNot set

Channel B ⊖ · yellowNot set

Channel B ⊕ · greenNot set

10:51▮▮▮ ▮

Serial: 413100 · Calibrated: 2021-06-17 · Firmware: 2.6

—

CFM @ 50.0 Pa

Vol: 19,200 cu ft| Target: 50.0 Pa| Avg: 5 s

Blower door fan

Range: Open

Speed: 0.0%

Range

Averaging

Baseline

Run the hoses, then start the fan.

Fan speed controller0%

4 · Take the reading

Range capacities and the fan curve are modeled approximations for teaching the sequence and the judgment. Confirm ring capacities and flow coefficients against the manual for the fan you actually put in the door.

Test house

1 · Prepare the enclosure

2 · Set the range ring on the fan

3 · Run the hoses

4 · Take the reading

5 · Work out the ACH50

Debrief