G. Negative Pressure
Negative pressure results from the imbalance of air avail- able for the fi replace to operate properly. Causes for this imbalance include:
•Exhaust fans (kitchen, bath, etc.).
•Range hoods.
•Combustion air requirements for furnaces, water heaters and other combustion appliances.
•Clothes dryers.
•Location of
•Imbalances of the HVAC air handling system.
•Upper level air leaks: recessed lighting, attic hatch opening, duct leaks.
WARNING
Asphyxiation Risk
This appliance produces carbon monoxide (CO).
•The free opening areas (in square inches) of the chimney damper as shown in the following tables must be met.
•User must make sure damper is locked open.
•The installer is responsible to ensure proper ventilation of fl ue gases before appliance is used.
Fire needs to draft properly for safe operation.
Table 1 for Factory Built Fireplaces
Free Opening Area (in square inches) of Chimney Damper for
Venting combustion Products from Decorative Appliances for
Installation in Solid Fuel Burning Fireplaces.
Chimney Ht. | 24 in. Log Set | 30 in. Log Set |
(Feet)* | Natural Gas | Natural Gas |
10 | not approved | not approved |
|
|
|
15 | 38.5 | 45.4 |
20 | 31.2 | 37.4 |
|
|
|
25 | 27.3 | 31.2 |
30 | 24.6 | 28.3 |
|
|
|
35 | 22.1 | 25.5 |
40 | 20.4 | 23.8 |
Table 2 for Masonary Built Fireplaces
Free Opening Area (in square inches) of Chimney Damper for
Venting combustion Products from Decorative Appliances for
Installation in Solid Fuel Burning Fireplaces.
Chimney Ht. | 24 in. Log Set | 30 in. Log Set |
(Feet)* | Natural Gas | Natural Gas |
6 | 64 | 71.4 |
|
|
|
8 | 59.7 | 66.9 |
|
|
|
10 | 54.3 | 60.2 |
15 | 48.8 | 54.1 |
|
|
|
20 | 44.4 | 49.1 |
30 | 40.3 | 44.5 |
*Height is measured from the hearth to the top of the chimney. Minimum height is 6 ft.
Table 3 for Minimum Fireplace Dimensions
Log Set | Front |
|
| Rear | Natural |
Size | Opening | Depth | Height | Width | BTU |
24 | 32 in. | 15 in. | 18 in. | 21 in. | 73,000 |
|
|
|
|
|
|
30 | 38 in. | 15 in. | 18 in. | 27 in. | 80,000 |
Hearth & Home Technologies • Grand Oak Match Light Gas Log Sets • | 5 |
