901175-00 NC
6
ihp.us.com
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)
20
30
40
50
60
70
80
90
100
110
120
Chimney
Height* (ft)
Minimum Opening** (sq. in.)
Max.
Input***
10
11.3
16.6
22.1
28.3
35.3
44.2
---
---
---
---
---
77.6
15
8.6
12.6
17.3
21.2
26.4
32.2
38.5
45.4
---
---
---
98.2
20
7.5
10.8
14.5
18.1
22.1
26.4
31.2
37.4
43.0
---
---
114.2
25
6.6
9.6
12.6
15.9
18.1
22.9
27.3
31.2
36.3
43.0
50.3
121.0
30
6.2
9.1
11.3
14.5
17.3
20.4
24.6
28.3
33.2
37.4
44.2
130.1
35
5.7
8.0
10.8
13.2
15.9
18.9
22.1
25.5
30.2
34.2
39.6
141.2
40
5.3
7.5
10.2
12.6
15.2
18.1
20.4
23.8
27.3
31.2
35.3
158.5
* Height is from hearth to top of chimney and the minimum height is 10 feet.
** Chart shows mainimum opening (sq. in.) for the given height and input rate.
*** Column marked ("Max input" corresponds to the maximum allowable input rate (kBTU/hr) for the given height.
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)
20
30
40
50
60
70
80
90
100
110
120
Chimney
Height* (ft)
Minimum Opening** (sq. in.)
6
17.6
25.7
33.8
41.7
49.2
56.6
64.0
71.4
78.8
86.2
93.5
8
16.5
23.7
31.2
38.7
45.5
52.4
59.7
66.9
74.1
81.3
88.6
10
15.1
21.7
28.7
35.2
41.7
48.2
54.3
60.2
66.1
72.0
77.9
15
14.1
19.9
26.1
32.0
37.7
43.2
48.8
54.1
59.4
64.6
69.9
20
12.9
18.5
23.7
28.8
34.3
39.8
44.4
49.1
53.8
58.4
63.0
30
12.2
16.9
21.6
26.5
31.2
35.9
40.3
44.5
48.6
52.7
56.6
* Height is from hearth to top of chimney and the minimum height is 10 feet.
** Chart shows mainimum opening (sq. in.) for the given height and input
INSTALLATION
Continued
