Heating and Ventilation Equipment and Appliances
Installation fundamentals
Heating appliances must be listed for the application, installed per the manufacturer's instructions, supported, and protected from physical damage. Clearances to combustibles come from the listing label, not from habit; where the label and code differ, the more restrictive requirement governs. Appliances must be accessible for service and replacement, and attic or crawlspace installations need a code-compliant access opening and passageway.
Location and safety
Appliances in garages must be protected from vehicle impact and elevated where required. Solid-fuel and open-flame appliances are restricted in bedrooms and bathrooms, while sealed-combustion, direct-vent, and electric units are generally acceptable. Appliances must not obstruct combustion air, and combustible storage must be kept away from heat-producing equipment. Safety controls, ignition systems, and disconnects must be present and operable.
Ventilation of spaces
Chapter 4 requires local exhaust for kitchens and bathrooms and mechanical ventilation for occupancies based on the ventilation-rate table. Exhaust from bathrooms and kitchens generally may not be recirculated into the space.
Exam traps
- Using a generic clearance instead of the label clearance.
- Forgetting that service access must allow removal of the appliance, not just a hand.
- Overlooking impact protection in garages.
- Assuming a bedroom installation is always prohibited.
Worked example
An electric furnace is installed in a closet. The label requires 6 inches at the front for service and zero at the sides. The closet must have a full access opening, and the appliance must be removable without cutting structural members.