NHIE Insulation and Ventilation 2 — Questions and Answers
Question 1: Which insulation material is manufactured primarily from recycled paper products treated with fire and pest retardants?
- Fiberglass
- Cellulose (Correct answer)
- Mineral wool
- Expanded polystyrene (EPS)
Correct answer: Cellulose
Cellulose insulation is made primarily from recycled newsprint and cardboard, treated with borate compounds for fire and pest resistance.
Question 2: What is 'thermal bridging' in building construction?
- Heat transfer through the insulation material itself
- Heat transfer through a structural element that bypasses the insulation layer (Correct answer)
- Reflection of radiant heat within an attic cavity
- Transfer of cold air through supply ductwork
Correct answer: Heat transfer through a structural element that bypasses the insulation layer
Thermal bridging occurs when a conductive material such as a wood stud or metal joist creates a path for heat to bypass the insulation installed between framing members.
Question 3: What fire hazard exists when insulation is placed directly over non-IC rated recessed light fixtures?
- Off-gassing from insulation chemicals near the fixture
- Electromagnetic interference disrupting the circuit
- Heat buildup around the fixture that can ignite surrounding materials (Correct answer)
- Increased moisture accumulation inside the fixture housing
Correct answer: Heat buildup around the fixture that can ignite surrounding materials
Non-IC (insulation contact) rated fixtures must maintain clearance from insulation; covering them traps heat that can reach ignition temperatures of surrounding materials.
Question 4: In cold climates, where should a vapor retarder be positioned relative to insulation in an exterior wall?
- On the cold exterior side of the insulation
- On the warm interior side of the insulation (Correct answer)
- In the center of the insulation layer
- Vapor retarders should be omitted in cold climates
Correct answer: On the warm interior side of the insulation
In cold climates, the vapor retarder belongs on the warm interior side to stop moisture-laden indoor air from reaching the cold sheathing where it would condense.
Question 5: What is the minimum clearance typically required between non-IC rated recessed light fixtures and attic insulation?
- 1 inch
- 2 inches
- 3 inches (Correct answer)
- 6 inches
Correct answer: 3 inches
Most building codes require a minimum 3-inch clearance between non-IC rated recessed fixtures and insulation to allow heat dissipation and prevent fire hazard.
Question 6: Which attic ventilation component uses a motor-driven fan to actively exhaust hot air?
- Ridge vent
- Soffit vent
- Power attic ventilator (PAV) (Correct answer)
- Gable end vent
Correct answer: Power attic ventilator (PAV)
Power attic ventilators use electrically powered fans to actively exhaust hot air from the attic, unlike passive vents that rely solely on natural convection.
Question 7: What occurs when warm moist interior air contacts a cold surface and releases moisture?
- Condensation at the dew point (Correct answer)
- Vapor diffusion
- Air infiltration
- Thermal bypass
Correct answer: Condensation at the dew point
Condensation occurs when air is cooled to its dew point temperature, causing water vapor to change phase to liquid water on the cold surface.
NHIE Insulation and Ventilation 2
Which insulation material is manufactured primarily from recycled paper products treated with fire and pest retardants?