18-CD34D1-5-EN 9
INSTALLER’S GUIDE
0
TABLE 2
MINIMUM AREA IN SQUARE FEET FOR
UNCONFINED SPACE INSTALLATIONS
FURNACE MAXIMUM
BTUH / INPUT RAT-
ING
WITH 8 FOOT CEILING
MINIMUM AREA IN SQUARE
FEET OF UNCONFINED SPACE
40,000
60,000
80,000
100,000
120,000
140,000
250
375
500
625
750
875
TABLE 3
MINIMUM FREE AREA IN SQUARE INCHES
EACH OPENING (FURNACE ONLY)
Furnace
Maximum
BTUH/INPUT
Rating
Air From
Inside
Air From Outside
Vertical
Duct
Horizontal
Duct
40,000
60,000
80,000
100,000
120,000
140,000
100
100
100
100
120
140
10
15
20
25
30
35
20
30
40
50
60
70
9
3. The following types of installations will require use
of OUT DOOR AIR for combustion, due to chemical
exposures:
*
Commercial buildings
*
Buildings with indoor pools
*
Furnaces installed in commercial laundry rooms
*
Furnaces installed in hobby or craft rooms
*
Furnaces installed near chemical storage areas.
*
Exposure to the following substances in the
combustion air supply will also require OUTDOOR
AIR for combustion:
* Permanent wave solutions
*
Chlorinated waxes and cleaners
*
Chlorine based swimming pool chemicals
* Water softening chemicals
*
Deicing salts or chemicals
*
Carbon Tetrachloride
* Halogen type refrigerants
*
Cleaning solvents (such as perchloroethylene)
* Printing inks, paint removers, varnish, etc.
* Hydrochloric acid
*
Cements and glues
*
Antistatic fabric softeners for clothes dryers
*
Masonry acid washing materials
