6
AIR FOR COMBUSTION AND VENTILATION
Determining
AIR FOR COMBUSTION AND VENTILATION
Continued
3.Add the Btu/Hr of all fuel burning appliances in the space.
| _____________ Btu/Hr | |
Gas water heater* |
| _____________ Btu/Hr |
Gas furnace |
| _____________ Btu/Hr |
Vented gas heater |
| _____________ Btu/Hr |
Gas fireplace logs |
| _____________ Btu/Hr |
Other gas appliances* + | _____________ Btu/Hr | |
Total | = | _____________ Btu/Hr |
*Do not include
VENTILATION AIR
Ventilation Air From Inside Building
This fresh air would come from an adjoining unconfined space. When ventilating to an adjoining unconfined space, you must provide two permanent openings: one within 12" of the ceiling and one within 12" of the floor on the wall connecting the two spaces (see options 1 and 2, Figure 4). You can also remove door into adjoining room (see option 3, Figure 4). Follow the National Fuel Gas Code, ANSI Z223.1/NFPA 54, Section 5.3, Air for Combustion and Ventilation for required size of ventilation grills or ducts.
Example: |
|
|
Gas water heater |
| 30,000 |
| _____________ Btu/Hr | |
+ | 10,000 | |
_____________ Btu/Hr | ||
Total | = | 40,000 |
_____________ Btu/Hr |
4.Compare the maximum Btu/Hr the space can support with the actual amount of Btu/Hr used.
__________________ Btu/Hr (maximum the space can support)
Ventilation
Grills
Into Adjoining
12"
Ventilation Grills Into Adjoining Room,
Room,
Or
Option 2
__________________ Btu/Hr (actual amount of Btu/Hr used)
Option 1
Remove
Example: 35,840 Btu/Hr (maximum the space can support) 40,000 Btu/Hr (actual amount of Btu/Hr used)
The space in the above example is a confined space because the actual Btu/ Hr used is more than the maximum Btu/Hr the space can support. You must provide additional fresh air. Your options are as follows:
A.Rework worksheet, adding the space of an adjoining room. If the extra space provides an unconfined space, remove door to adjoining room or add ventilation grills between rooms. See Ventilation Air From Inside Building.
B.Vent room directly to the outdoors. See Ventilation Air From Out- doors, page 7.
C.Install a lower Btu/Hr fireplace, if lower Btu/Hr size makes room unconfined.
If the actual Btu/Hr used is less than the maximum Btu/Hr the space can support, the space is an unconfined space. You will need no additional fresh air ventilation.
WARNING: If the area in which the fireplace may be operated is smaller than that defined as an uncon- fined space or if the building is of unusually tight construction, provide adequate combustion and ven- tilation air by one of the methods described in the National Fuel Gas Code, ANSI Z223.1/NFPA 54 Sec- tion 5.3 or applicable local codes.
Door into Adjoining Room, Option 
3
12"
Figure 4 - Ventilation Air from Inside Building
For
.
.com
