Residential Building Inspector B1Building Planning and Life SafetyHard
A residential building inspector is reviewing plans for a new home that includes a permanently installed unvented room heater. What is the maximum allowable input rating for this unvented room heater?
- A10,000 Btu/h
- B20,000 Btu/h
- C40,000 Btu/h
- D6,000 Btu/h
Show answer & explanationAnswer & explanation
Correct answer: A. 10,000 Btu/h
According to the 2021 IRC, Section G2448.1 (621.1), unvented room heaters are limited to a maximum input rating of 10,000 Btu/h (3 kW) for a single appliance and 10,000 Btu/h total for multiple appliances in a dwelling unit.
Why the other options are wrong
- B. 20,000 Btu/h exceeds the maximum allowable input rating for unvented room heaters.
- C. 40,000 Btu/h significantly exceeds the maximum allowable input rating for unvented room heaters.
- D. 6,000 Btu/h is less than the maximum allowable and not a specific limit.
Unvented Room Heater Input Rating
The maximum heat output capacity of an unvented room heater, regulated to ensure indoor air quality and safety.
- Unvented heaters release combustion products directly into the living space.
- Strict limits are placed on their size and use.
- Specified in IRC Section G2448.1 (621.1).
Memory trick: Unvented heaters, small and few, keep the air clean, just for you.