• INFORM THE HOUSE OCCUPANTS & OWNERS ABOUT THE TEST BY LETTER OR PHONE:
  • Air leakage is about 1/3 of heat loss of house and it is uncomfortable.
  • Blower door test will find what kind of leaks your house has.
    
  • The test will be like a 20 mph wind on all sides of the house.
    
  • A large fan is sealed into an outside door and air is blown out of the house.
    
  • Leaks can be detected with by feeling with the hand or with a smoke puffer.
    
  • The test is not dangerous and everyone can remain in the house during the test.
    
  • The test will help to determine if how much leak sealing is reasonable.
    
  • The furnace MUST be shut off during test.
    
  • The blower door test is unlikely to damage house, but may change the temperature.
    
  • The test MUST NOT be done with fires in fireplaces, furnaces or stoves.
    
  • Ashes in fireplaces MUST BE REMOVED OR COVERED and dampers closed to avoid ashes in house.
    
  • Ask occupants where they think the worst drafts are.
    
  • Close and seal outside doors and windows as if winter (any storm windows on).
    
  • We will need to go in all rooms, attic & basement to look for leaks.
    

• ARRIVE AT SITE - EXPLAIN TEST AND PREPARE THE HOUSE:
  • Greet occupant and reconfirm permission to do the test.
  • Go over everything in the introductory information.
  • Check to see if they are comfortable with idea of test and answer all questions.
  • Inspect house preparation:
    • Are there any fireplaces or stoves for heating?
    • Are all fires out in stove and fireplaces?
    • Have ashes been removed and are dampers closed?
    • If ashes not removed, cover with newspapers & weight
    • Have all doors and windows been closed & latched with storms on?
    • Are all interior doors open, except closets?
    • Is the basement heated (lived in) an to be included with envelope?
    • Adjust thermostat to keep furnace off even it temperature drops.
  • Ask homeowner for their ideas where the worst/uncomfortable leaks are.
  • Bring in blower door gauges and set them up so they can warm up before the test.

• DEFINE THE HOUSE THERMAL ENVELOPE
  • Ask yourself, "What parts of house are heated above 45F?"
  • Is the basement is part of the thermal envelope? Open the basement door if it is.
  • The walls, ceilings, and floors that enclose the heated volume are the thermal envelope.
  • Measure the outside dimensions of the and compute house volume (cu ft).
  • Optional: Compute surface area of walls, floors and ceilings (sq ft).

• SET UP BLOWER DOOR
  • Install the Door Frame in a house door jamb.
    • Select door on the side of house shielded from wind.
    • Assemble the blower door frame with the cams closed.
    • Expand the door frame to roughly fit the door jamb and tighten knobs.
    • Remove the door frame and attach the nylon cover.
    • Connect exterior house pressure hose to the outside of the nylon door panel.
    • Run the exterior house pressure hose away from the fan flow direction.
    • Install the door frame in the door jamb and open the cams to lock it into the jamb.
    • Check for leaks and reinstall if necessary.
  • Install fan in the depressurization direction (fan blowing out).
    • Insert the fan into the elastic seal around the door cover hole.
    • Check for leaks and adjust the fan seal (if necessary).
  • Set up the gauges on the door jamb.
    • Attach the gauge clamp to the door jamb at viewing height.
    • Attach the gauges to the gauge clamp.
  • Connect the pressure tubing to the gauges and outside.
    • Connect the fan pressure hose between the fan and gauges.
    • Connect interior house pressure hose between the nylon door panel and the house pressure gauge.
    • Make sure that exterior house pressure hose is not exposed to the fan flow.
  • Connect the electrical plugs.
    • Connect the fan speed control plug to the female plug to the fan.
    • Turn off the fan speed control switch.
    • Connect the male fan plug to an extension cord connected to a wall AC power outlet.
  • Carefully zero the pressure gauges.
    • Turn on the fan and run up the power several times so that the gauges move.
    • Adjust the gauges to zero.
    • Tap the gauges gently to make them come to zero.
    • Repeat the last three steps until the gauges come to a consistent zero.

• RECORD WEATHER CONDITIONS
  • Record inside temperature (within 5 degrees F) for use in air density calculations.
  • Record outside temperature (within 5 degrees F) for use in air density calculations.
  • Record wind conditions (calm, gusty, very windy, etc.) for use in evaluating measurement quality

• MEASURE AIR FLOW AND PRESSURE
  • Adjust the fan speed for a house pressure of 50 Pascals (this is the same as 0.20 inches of water).
  • If you can not get up to 50 Pa, use highest pressure you can reach.
  • Check for open windows and doors that have come open.
  • If the flow gauge reading is too low to read, install the Low-flow plate.
  • If using the low-flow plate, move fan pressure hose to low-flow plate pressure tap.
  • Record pressure and flow.
  • When the fan is running slowly, use the low speed switch for more sensitivity and fan cooling.

• ANALYZE DATA
  • There are several ways to analyze data and here is a simple one:
  • Calculate house volume in cubic feet (example: 1500 sq ft * 8 ft = 12000 cu ft)
  • Inside and outside temperature can be used to correct data with computer.
  • Use 50 Pa pressure and flow data (example: 50 Pa and 2000 cfm)
  • Compute 50 Pa Air Changes/Hour (ACH50)
  • Example: ACH50 = 2000 cfm * 60 min/hr /12000 cu ft = 10 ACH50)
  • Use "can't reach" table if house is too leaky to get to 50 Pa
  • Compute natural infiltration by dividing ACH50 by 20 (approximate)
  • Example: 10 ACH50 / 20 = 0.5 ACH natural infiltration
  • Minimum Infiltration: ASHRAE recommends a minimum Infiltration = .35 ACH
  • This suggests a minimum ACH50 = 20 * .35 = 7 ACH50
  • Houses that are leakier than 7 ACH50 should generally be airsealed.

• SEARCH FOR LEAKS
  • Check each room for major leakage by partially closing each interior door and feeling for air flow through the door crack.
  • Use our hand or a smoke puffer to find individual leaks.
  • Remember that leaks in the upper part of the house cause the worst heat loss.

• TAKE DOWN THE BLOWER DOOR
  • Turn off the Fan Speed Control.
  • Disconnect the two Electrical Plugs.
  • Disconnect the two pressure hoses.
  • Remove the fan from door.
  • Release door frame cams.
  • Remove the door frame from the door jamb.
  • Disconnect door frame and store in case.
  • Remove the gauges and gauge clamp from the door jamb.

• FINISH TEST AND RESTORE HOUSE TO ORIGINAL CONDITION
  • Turn on thermostat/furnace and warm up house if necessary.
  • Return all doors and windows to original setting.
  • Pack up all blower door equipment and return to truck.
  • Remove any covers from fireplace or stove ashes.
  • Thank occupants for their cooperation.

For further assistance, call Infiltec toll free at (888) 349-7236.

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