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Duct Leakage Testing - Problem Set 3.1

Source(s) or Contributor(s)
Pacific Northwest National Laboratory
Question
  1. What is the approval leakage limit according to RESNET-approved testing protocol for total duct leakage testing for a home at rough-in?
    1. < 2 CFM25 per 100 ft2 of conditioned floor area
    2. < 4 CFM25 per 100 ft2 of conditioned floor area
    3. < 2 CFM25 per 50 ft2 of conditioned floor area
    4. < 4 CFM25 per 50 ft2 of conditioned floor area
  2. How should a blower door and duct tester be installed for conducting a duct leakage to the outdoors test?
    1. The blower door should be set up to pressurize the home and the duct tester should be set up to pressurize the duct system.
    2. The blower door should be set up to depressurize the home and the duct tester should be set up to depressurize the duct system.
    3. Either a. or b.
  3. During a test for duct leakage to the outdoors, the first measurement with the duct tester pressure probe in the return duct read a leakage of 40 CFM, and the second measurement with the duct tester pressure probe in a supply duct as far as possible from the return the duct tester is connected to read a leakage of 120 CFM.  What is the average measured duct leakage to the outdoors, and where is the greater source of leakage?
  4. What steps are done differently in a duct leakage to the outdoors test compared to a total duct leakage test?