16
FIREPLACE PREPARATION
FOR FACTORY BUILT FIREPLACES
Free Opening Area of Chimney Damper For Venting Combustion Products From
Decorative Appliances For Installation In Solid-Fuel Burning Fireplaces
Appliance Input Rate
(kBTU/hr)
30
40
50
Chimney
Height* (ft)
Minimum Opening** (sq. in.)
10
16.6
22.1
28.3
15
12.6
17.3
21.2
20
10.8
14.5
18.1
25
9.6
12.6
15.9
30
9.1
11.3
14.5
35
8.0
10.8
13.2
40
7.5
10.2
12.6
*
Height is from hearth to top of chimney and the minimum height is 10 feet.
** Chart shows minimum opening (sq. in.) for the given height and input rate.
FOR MASONRY BUILT FIREPLACES
Free Opening Area Of Chimney Damper For Venting Combustion Products
From Decorative Appliances For Installation In Solid-Fuel Burning
Fireplaces
Appliance Input Rate
(kBTU/hr)
30
40
50
Chimney
Height* (ft)
Minimum Opening** (sq. in.)
6
25.7
33.8
41.7
8
23.7
31.2
38.7
10
21.7
28.7
35.2
15
19.9
26.1
32.0
20
18.5
23.7
28.8
30
16.9
21.6
26.5
* Height is from hearth to top of chimney and the minimum height is 6 feet.
** Chart shows minimum opening (sq. in.) for a given height and input rate.
