User Manual

10
TABLE II
PERMISSIBLE CLEARNCES WITH
SPECIFIED FORMS OF PROTECTION
(Clearance in Inches)
WHERE THE REQUIRED CLEARANCE WITH NO PROTECTION IS:
36 INCHES 18 INCHES 12 INCHES 6 INCHES
TYPE OF PROTECTION
SEE NOTE
ABOVE SIDES
REAR
ABOVE SIDES
REAR
ABOVE SIDES
REAR
ABOVE SIDES
REAR
¼” asbestos millboard spaced out 1”*
30 18 15 9 9 6 3 2
28 gauge sheet metal on ¼” asbestos
millboard
24 18 12 9 9 6 3 2
28 gauge sheet metal space out 1”*
18 12 9 6 6 4 2 2
28 gauge sheet metal on 1/8” asbestos
millboard spaced out 1”*
18 12 9 6 6 4 2 2
1-½” asbestos cement covering on heating
appliance
18 12 9 6 6 4 2 1
¼” asbestos millboard on 1” rockwool batts
reinforced with wire mesh or equivalent
18 12 6 6 4 4 2 2
22 gauge sheet metal on 1” rockwool batts
reinforced with wire mesh or equivalent
18 12 4 3 2 2 2 2
¼” asbestos cement board or ¼” asbestos
millboard
36 36 36 18 12 12 4 4
¼” cellular asbestos
36 36 36 18 12 12 3 3
*Spacer shall be of non combustible material
LIMIT OF TOXIC VAPORS AND GASES
DURING NORMAL OPERATION OF THE HEATER, THE CONTENT OF TOXIC VAPORS AND
GASES IN THE TEMPERED AIR AT THE POINT OF DISCHARGE INTO THE BUILDING MUST BE
SUCH THAT NO IRRITATING EFFECTS ARE EVIDENT. THE INSTALLATION SHALL NOT BE
CONSIDERED ACCEPTABLE IF THE DISCHARGE OF TOXIC PRODUCTS IS KNOWN TO EXCEED
THE LIMITS SET OUT IN THE FOLLOWING TABLE.
SUBSTANCE PERCENT PPM SUBSTANCE PERCENT PPM
Acetaldehyde .001 10 Formaldehyde .000025 0.25
Carbon Dioxide .250 2500 Nitrogen Dioxide .0001 1
Carbon Monoxide .001 10 Sulfur Dioxide .00005 0.5
NOTE: At 100°F the CO
2
concentration will be in the order of 2500 P.P.M.