5
INSTALLATION
COMBUSTION & VENTILATION |
| DETERMINING CONFINED OR UNCON- |
AIR PROVISIONS |
| FINED SPACE |
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This heater shall not be installed in a confined space or unusually tight construction unless provisions are provided for adequate combustion and ventilation air.
In order to avoid the possibility of exposed insulation or vapour barrier coming in contact with the fireplace body, it is recommended that the walls of the fireplace enclosure be ‘finished’, (i.e. drywall/sheetrock) as would any other outside wall of the home. This will ensure that clearance to combustibles is maintained within the cavity.
The National Fuel Gas Code, ANSI Z223.1 defines a confined space as a space whose volume is less than 50 cubic feet per 1,000 Btu per hour (4.8 m3 per kW) of the aggregate input rating of all appliances installed in that space and an unconfined space as a space whose volume is not less than 50 cubic feet per 1,000 Btu per hour (4.8 m3 per kW) of the aggregate input rating of all appliances installed in that space. Rooms communicating directly with the space in which the appliances are installed, through openings not furnished with doors are considered a part of the unconfi ned space.
To determine the volume of the room where the heater is to be installed, multiply the width x the length x the ceiling height of that room measured in feet. If any adjoining rooms are con- nected by grills or openings such as kitchen
Multiply the room volume by 1000 and divide this amount by 50 to determine the maximum Btu/hr that the space can support with adequate combustion and ventilation air.
Add the Btu/hr of all fuel burning appliances located within the space such as gas furnace, gas water heater, etc. Do not include direct vent gas appliances which draw their input and output air from and to the outdoors.
WARNING: If the area in which the heater may be operated is smaller than that defi ned as an unconfi ned space or if the building is of unusually tight construction, provide adequate combustion and ventilation air by one of the methods de- scribed in the National Fuel Gas Code ANSI Z223.1, Section 5.3 or the applicable local code.
The CVF36 is rated at 30,000BTUs per hour and therefore requires a minimum unconfined space of 1,500 cubic feet.
ROOM 1
HEIGHT
LENGTH
ROOM 2
FIGURE 1
If for example,
the length of the rooms is 10 feet, the width of Room 1 is 10 feet, the width of Room 2 is 15 feet the height of the rooms is 8 feet.
The volume of Room 1: 10 x 10 x 8 = 800 cubic feet. The volume of Room 2: 10 x 15 x 8 = 1200 cubic feet.
Room Volume = Length x Width x Height Max BTU/hr = Room Volume x 1000 ÷ 50
EXAMPLE 1
In this example, because there is no door to the adjoining room, the volume of the adjoining room may be added to the volume of the room with the heater to get a total unconfi ned space.
The total unconfi ned space: 800 + 1200 = 2000 cubic feet.
Maximum BTU/h: 2000 x 1000 = 40,000 BTU/h 50
If there are no more fuel burning appliances within this space then the 30,000 BTU/h input of the fi replace is suitable to be installed. This also assumes that the construction of this space is not unusually tight.
EXAMPLE 2
If in this example a solid door separates Room 1 from Room 2, the volume of Room 2 could not be used. In this case the maximum BTU/h would be:
Maximum BTU/h: 800 x 1000 = 16,000 BTU/h
50
This would be considered a confi ned space since it can not support the 30,000BTU/h input of the heater and it would be necessary to provide adequate combustion and ventilation air to Room 1.