Determining Confined Or Unconfined Space - Napoleon GVF40P Installation And Operating Instructions Manual

8
2.2

DETERMINING CONFINED OR UNCONFINED SPACE

To determine the volume of the room where the appliance 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 connected by grilles or openings
such as kitchen pass-throughs, etc., the volume of those rooms may be added to the total.
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
appliance, etc. Do not include direct vent gas appliances which draw their input and output air from and to the
outdoors.
IF THE AREA IN WHICH THE APPLIANCE MAY BE OPERATED IS SMALLER THAN THAT DEFINED AS
AN UNCONFINED SPACE OR IF THE BUILDING IS OF UNUSUALLY TIGHT CONSTRUCTION, PROVIDE
ADEQUATE COMBUSTION AND VENTILATION AIR BY ONE OF THE METHODS DESCRIBED IN THE
NATIONAL FUEL GAS CODE ANSI Z223.1, SECTION 5.3 OR THE APPLICABLE LOCAL CODE.
Unusually tight construction is defi ned as construction where:
A) Walls and ceilings exposed to the outside atmosphere have a continuous water vapour retarder with a
rating of 1 perm (6 x 10-11 kg per pa-sec-m2) or less with openings gasketed or sealed, and
B) Weather stripping has been added on openable windows and doors, and
C) Caulking or sealants are applied to areas such as joints around window and door frames, between sole
plates and fl oors, between wall-ceiling joints, between wall panels, at penetrations for plumbing, electrical,
and gas lines, and at other openings.
An unvented room appliance is recommended for use as a secondary heat source rather than as a primary
source. Gas combustion produces water vapour which could occur at the rate of approximately one ounce of
water for every 1,000 BTU/hr of gas input. During the cold weather season, indoor humidity levels tend to be
low. Consequently, this water vapour can enhance the living space. However if a problem should occur:
A) Ensure suffi cient combustion and circulation air
B) Use a dehumidifi er
C) Do not use the unvented room appliance as a primary heat source
Without suffi cient fresh air for proper operation, poor fuel combustion can result. Carbon Monoxide is a result
of poor combustion.
If additional fresh air is required, use one of the methods described in the National Fuel Gas Code, ANSI
Z223.1, Section 5.3 or the applicable local code.
Room Volume = Length x Width x Height
Max BTU/hr = Room Volume x 1000 / 50
W415-0810 / 06.11.09
ROOM 1
HEIGHT
LENGTH
WARNING
!
ROOM 2
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: 10x10x8 = 800 cubic feet
The volume of Room 2: 10x15x8 = 1200 cubic feet
FIGURE 2.2
19.1