6
UVLC Series
4.
Compare the maximum BTU/hour rating the space
can support with the total BTU/hour used by the appli-
ances.
Example: 76,800 BTU/hour the space can support
80,000 BTU/hour used by appliances
In this example, the maximum BTU/hour that the space
can support is less than the total used by the appli-
ances. The space is considered to be
Confined Space.
Additional air must be provided to meet the require-
ments on the vent-free gas log set.
The installation and the provisions for combustion and
ventilation air must conform with the National Fuel Gas
Code, ANSI Z223.1/NFPA 54, or the CSA-B149.1 Instal-
lation Code (Series).
A confined space may be ventilated in two ways:
A.
Open up or provide at least two ventilating grilles to
an adjoining unconfined space. (Fig. 2)
Each of the two grilles must provide an opening of at
least 50 square inches, with all opening dimensions be-
ing at least 3”. One grille must be within 12” of the ceil-
ing; the other within 12” of the floor. (If the total exceeds
100,000 BTU/hour, additional grilles will be needed.)
B.
Vent the room directly to the outdoors. (Provide one
square inch of opening for each 4,000 BTU/hr.)
For further information on ventilation guidelines and siz-
ing specifications, follow the National Fuel Gas Code/
NFPA 54/ANSI Z223.1/NFPA 54, Section 5.3.
If the total BTU/hour used by the appliances is less than
the maximum BTU/hr the space can support, the room
meets the
Unconfined Space
criteria and no further
ventilation is needed.
WARNING:
Before installing the gas log set in a solid-
fuel burning fireplace, the chimney flue and firebox must
be cleaned of soot, creosote, and loose paint by a quali-
fied chimney cleaner.
WARNING
This heater shall not be installed in a confined
space or unusually tight construction unless
provisions are made for adequate combustion
and ventilation air.
WARNING
If the area in which the heater 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/
NFPA 54, 1992, Section 5.3, or applicable codes.
VO370-2
Ventilation
options
3/26/99 djt
Fig. 2
Ventilation options for confined spaces.
OPTION 1 -
Vents to Ad-
joining Rooms
OPTION 2 -
Remove Door
to Adjoining
Room
OPTION 3 -
Vents to Ad-
joining Rooms
12”
12”
VO370-2
Example:
Gas Range
55,000 BTU/hour
Vent-Free LogSet
+25,000 BTU/hour
Total
80,000 BTU/hour
