Practice Test Geeks(HERS) Certified Home Energy Rating System Rater Practice Test
← All HERS Flashcard Decks

Blower Door & Duct Testing Flashcards

6 cards from real HERS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Blower Door & Duct Testing flashcards as text

  1. A HERS Rater is performing a blower door test on a 2,500 sq ft house with 8-foot ceilings. The final reading on the manometer is 1,800 CFM50. What is the approximate Air Changes per Hour at 50 Pascals (ACH50)?

    Answer: 5.40 ACH50

    To calculate ACH50, use the formula: (CFM50 * 60) / Conditioned Volume. First, find the volume: 2,500 sq ft * 8 ft = 20,000 cubic feet. Then, apply the formula: (1,800 CFM50 * 60) / 20,000 cu ft = 108,000 / 20,000 = 5.4 ACH50.

  2. According to ANSI/RESNET/ICC 380, what is the standard pressure difference that must be induced across the building envelope for a single-point blower door test?

    Answer: 50 Pascals

    The ANSI/RESNET/ICC 380 standard specifies that blower door tests for measuring building envelope airtightness are conducted at a pressure difference of 50 Pascals (Pa) with respect to the outdoors.

  3. When performing a duct leakage to outside test, what is the primary function of the blower door?

    Answer: To pressurize or depressurize the house to the same pressure as the duct system (typically 25 Pa).

    In a duct leakage to outside test, the blower door is used to pressurize (or depressurize) the house to the same pressure as the duct system, which is typically 25 Pa. This equal pressure neutralizes any leakage between the ducts and the conditioned space, so the duct tester only measures air leaking to the outside of the conditioned envelope.

  4. A HERS Rater is preparing a home for a blower door test according to RESNET standards. Which of the following should be done to prepare the house?

    Answer: Close and latch exterior windows and doors, but do not apply extra sealing.

    Per ANSI/RESNET/ICC 380, exterior windows and doors should be closed and latched as they would be normally, without extra sealing beyond the standard weatherstripping. Interior doors must be opened, HVAC systems turned off, and dampers must be closed but not sealed.

  5. Which of the following scenarios describes a 'Total Duct Leakage' test?

    Answer: A test that measures all the air leaking from the duct system, regardless of whether it leaks into conditioned or unconditioned space.

    A 'Total Duct Leakage' test measures all the air escaping from the duct system, including leaks to the inside of the conditioned space and leaks to the outside (e.g., attics, crawlspaces). This is distinct from a 'Leakage to Outside' test, which isolates only the leaks to unconditioned areas.

  6. When performing a duct leakage test in accordance with ANSI/RESNET/ICC 380, the duct system is typically pressurized or depressurized to what pressure differential relative to the surrounding space?

    Answer: 25 Pa

    The standard test pressure for both total duct leakage and leakage to the outdoors, as specified by RESNET standards, is 25 Pascals (0.10 inches water column).