70D0004
6
TPB Series Log Set
ADEQUATE COMBUSTION and VENTILATION AIR
ADEQUATE COMBUSTION AND VENTILATION AIR
This heater shall not be installed in a confined space or unusually tight construction unless provisions are
provided for adequate combustion and ventilation air.
The National Fuel Gas Code, (ANSI Z223.1/NFPA 54)
, defines a confined space as a space whose volume
is less than 50 cubic feet per 1,000 BTU per hour (4.8 m
3
per kw) of the aggregate input rating of all appli-
ances installed in that space. An unconfined space is defined as a space whose volume is not less than 50
cubic feet per 1,000 BTU per hour (4.8 m
3
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 unconfined space.
UNUSUALLY TIGHT CONSTRUCTION IS DEFINED AS CONSTRUCTION WHERE…
a) walls and ceilings exposed to the outside atmosphere have a continuous water vapor retarder with a rating
of 1 perm (6 x 10
11
kg per pa-sec-m
) or less with openings gasketed or sealed;
b) weather striping 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 floors, between wall-ceiling joints, between wall panels, at penetrations for plumbing, elec-
trical, and gas lines, and at other openings.
The following formula can be used to determine the maximum heater rating per the definition
of unconfined space:
(L
1
+ L
) Ft x (W) Ft x (H) Ft
50
Consider two connecting rooms with an open area between, with the following dimensions:
L
1
= 15
Z\x
Ft., L
= 1 Ft., W = 1 Ft., H = 8 Ft.
(15
Z\x
+ 1) x (1) x (8)
50
If there were a door between the two rooms the calculation would be based only on the room
with the heater.
(15
Z\x
) x (1) x (8)
50
x 1000
x 1000 = 5800 BTU/hr
x 1000 = 9,760 BTU/hr
BTU/hr =
BTU/hr =
BTU/hr =
FP2000
log clearances
W
H
Figure 1 -
Example of a Large Room with 1/2 Wall Divider
Counter
Fireplace
W
ARNING
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, Air for
Combustion and Ventilation or applicable
local codes.