Monessen Hearth MJ27NR User Manual
Page 8
8
86D0024
FP2000
log clearances
W
H
The following formula can be used to determine the maximum heater rating per the definition of
unconfined space:
BTU
/
hr
=
(L1 + L2) Ft x (W) Ft x (H) Ft.
x 1000
BTU
/
hr
50
Consider two connecting rooms with an open area between, with the following dimensions:
L
1
= 15
1
/
2
Ft., L
2
= 12 Ft., W = 12 Ft., H = 8 Ft.
BTU
/
hr
=
(15
1
/
2
+ 12) x (12) x (8)
x 1000 = 52800
BTU
/
hr
50
If there were a door between the two rooms the calculation would be based only on the room
with the heater.
BTU
/
hr
=
(15
1
/
2)
x (12) x (8)
x 1000 = 29760
BTU
/
hr
50
GENERAL INSTALLATION INFORMATION
Figure 1 - Example of a Large Room with 1/2 Wall Divider
Counter
Fireplace
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, Section 5.3 or applicable local codes.
W
ARNING