BPI Health, Safety & Energy Efficiency 5 — Questions and Answers
Question 1: What is the minimum whole-house mechanical ventilation rate for a 1,500 sq ft home with 3 occupants per ASHRAE 62.2-2016?
- 30 CFM
- 45 CFM
- 52.5 CFM (Correct answer)
- 75 CFM
Correct answer: 52.5 CFM
ASHRAE 62.2 formula: 0.01 × floor area + 7.5 × (occupants + 1) = 0.01×1500 + 7.5×4 = 15 + 30 + 7.5 = 52.5 CFM.
Question 2: Which combustion appliance configuration provides the highest level of safety against backdrafting?
- Atmospherically vented Category I appliance
- Power-vented appliance with induced draft fan
- Sealed combustion (direct vent) appliance (Correct answer)
- Natural draft appliance with a B-vent flue
Correct answer: Sealed combustion (direct vent) appliance
Sealed combustion appliances draw combustion air directly from outdoors and vent directly outside, completely isolating combustion from indoor air.
Question 3: What is the primary purpose of performing a duct leakage test in the context of health and safety?
- To quantify energy waste from duct losses
- To identify leaks that may draw combustion gases or attic pollutants into the living space (Correct answer)
- To verify duct sizing meets ACCA Manual D requirements
- To ensure balanced airflow to all rooms
Correct answer: To identify leaks that may draw combustion gases or attic pollutants into the living space
Duct leaks in unconditioned spaces can draw in soil gases, attic pollutants, or combustion byproducts and distribute them throughout the home.
Question 4: A home has a central exhaust-only ventilation system. What is a key disadvantage of this approach from an IAQ perspective?
- It uses more energy than supply-only systems
- It cannot control where make-up air enters, potentially drawing from unconditioned or contaminated spaces (Correct answer)
- It always over-ventilates the home
- It requires a more complex control system than balanced ventilation
Correct answer: It cannot control where make-up air enters, potentially drawing from unconditioned or contaminated spaces
Exhaust-only systems depressurize the home, and make-up air infiltrates through random leakage points that may introduce pollutants from crawl spaces or garages.
Question 5: Which test protocol should an analyst use to evaluate a gas appliance flue for CO at the point of highest measurement accuracy?
- Measure ambient CO in the center of the room
- Insert a combustion analyzer probe into the flue breach above the draft diverter (Correct answer)
- Test at the burner opening with a handheld CO meter
- Measure CO at the exterior termination of the flue
Correct answer: Insert a combustion analyzer probe into the flue breach above the draft diverter
Inserting the probe above the draft diverter or at the flue breach provides an undiluted sample of combustion gases for accurate CO measurement.
Question 6: What indoor relative humidity range minimizes both mold growth and respiratory irritation for most occupants?
- 20–30%
- 30–50% (Correct answer)
- 50–70%
- 70–80%
Correct answer: 30–50%
Maintaining indoor RH between 30% and 50% inhibits mold growth while preventing the dry air that irritates mucous membranes.
Question 7: A BPI auditor notices that a newly installed bathroom exhaust fan vents into the attic rather than to the exterior. What is the primary concern?
- Increased attic temperature in summer
- Moisture accumulation in the attic leading to mold and structural damage (Correct answer)
- Reduced bathroom ventilation effectiveness
- Noise transmission through the attic floor
Correct answer: Moisture accumulation in the attic leading to mold and structural damage
Exhausting humid bathroom air into the attic deposits moisture that can condense on cold surfaces, promoting mold growth and wood rot.
BPI Health, Safety & Energy Efficiency 5
What is the minimum whole-house mechanical ventilation rate for a 1,500 sq ft home with 3 occupants per ASHRAE 62.2-2016?