Vermont Castings Radiance RUVS40 Homeowner's Installation And Operating Manual page 7

3. Add the BTU/Hr ratings of all fuel-burning appli-
ances installed in the same space, including the
following:
Gas Water Heater
Gas Fireplace Logs
Vented Gas Heater*
* Do not include Direct Vent appliances as these
utilize outside air for combustion and vent to the
outdoors.
Example:
Gas Range
Unvented Heater +33,000 BTU/Hr
Total
4. Compare the maximum BTU/Hr rating the space can
support with the total BTU/Hr used by the appliances.
Example:
76,800 BTU/Hr - max. the space can support
88,000 BTU/Hr - total used by appliances
In this example, the maximum BTU/Hr that the
space can support is less than the total used by the
appliances, the space is considered to be Confined
space . Additional air must be provided to meet the
requirements of the Unvented heater.
A confined space may be ventilated in two ways:
A) Open up or provide at least two ventilating grilles
to an adjoining unconfined space. Use any of the
options illustrated in Figure 4.
Fig. 4 Vent options to provide additional air.
Gas Furnace
Unvented Gas Heater
Other Gas Appliances*
55,000 BTU/Hr
88,000 BTU/Hr
Option 2 -
Remove
Door
between
Adjoining
Rooms
Option 1
Vents to
Adjoining
Room
Vermont Castings Radiance
Each of the two grilles must provide an opening of
at least 50 square inches, with all opening dimensions
being at least 3". One grille must be located within 12"
of the ceiling; the other within 12" of the floor. (If the
total exceeds 100,000 BTU/Hr, additional grilles will be
required.)
B) Vent the room directly to the outdoors. (Provide
one square inch of opening for each 4,000 BTU/hr.
If the total BTU/Hr used by the appliances is less
than the maximum BTU/Hr the space is able to sup-
port, the room meets the Unconfined space criteria and
no further ventilation is required.
For further information on ventilation guidelines
and sizing specifications follow the National Fuel Gas
Code NFPA 54/ANSI Z223.1 Section 5.3.
WARNING
THIS HEATER SHALL NOT BE INSTALLED IN A
CONFINED SPACE UNLESS PROVISIONS ARE
PROVIDED FOR ADEQUATE COMBUSTION AND
VENTILATION AIR.
IF THE AREA IN WHICH THE HEATER MAY BE
OPERATED IS SMALLER THAN THAT DEFINED
AS AN UNCONFINED SPACE, PROVIDE
ADEQUATE COMBUSTION AND VENTILATION AIR
BY ONE OF THE METHODS DESCRIBED IN THE
NATIONAL FUEL GAS CODE, ANSI Z223.1, 1992,
SECTION 5.3.
12"
Option 3 -
Vents to Adjoining
Room
12"
ST184
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