Furnace clearances

Heating · Furnace Cabinets · printed page 123 (PDF page 124)

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Book index entries

Combustible Clearances – for Furnaces Furnace Clearances

Text in the illustration

the top of the supply plenum typically requires a 1 inch clearance to combustible ceiling or framing
return
air flow
vent connector
supply
required rear and side clearances are usually minimal while front clearances are greater due to access requirements

Generated explanation

The illustration shows a cutaway of an upflow furnace with a blower at the bottom, heating components above, a return duct on the left, and a supply plenum extending upward into a horizontal duct. Blue and red arrows indicate downward return airflow and upward and horizontal supply airflow, respectively. A vent connector rises from the furnace and turns to the left. Dimension arrows identify the clearance between the supply plenum and the combustible ceiling framing, with an annotation stating that 1 inch is typically required. Another annotation explains that rear and side furnace clearances are usually minimal, while greater front clearance is required for access.

Components

furnace cabinet blower burner assembly heat exchanger return air duct supply plenum supply air duct vent connector ceiling framing floor slab

Materials

sheet metal wood framing concrete