De-rating for High Altitude
For u.s. installations, the clarity Direct vent is approved for elevations up to 2000 feet using the factory-installed burner
injectors. at elevations above 2000 feet, u.s. codes require a decrease in the input rating by changing the burner injectors
to a smaller size. The chart below lists by part numbers the appropriate injectors for both LP and natural gas at various
altitudes.
For canadian installations, the clarity Direct vent is approved for elevations up to 1375 meters (4500 feet). When installing
the clarity Direct vent at altitudes above 1375 meters (4500 feet), consult the local gas distributor or the authority having
jurisdiction for proper rating methods.
note: the difference in altitude derating requirements for the u.s. and canada is simply a result of differences in testing
standards between the two countries.
if the installer must convert the unit to adjust for varying altitudes, an information sticker like the one to the right must be
filled out and affixed to the appliance at the time of conversion.
NATURAL GAS
Front
Harman
Center Harman
Rear
Harman
Nominal Btu
Altitude
Injector Part No.
Injector Part No.
Injector Part No.
Input Rate
0-2000'
47
3-40-64347
56
3-40-57356
39
3-40-64739
40,000
2000-3000'
48
male
56
3-40-57356
40
male
38,400
3000-4000'
49
male
56
3-40-57356
41
male
36,900
4000-5000'
49
male
57
male
42
male
35,400
5000-6000'
50
male
57
male
42
male
34,000
6000-7000'
50
male
57
male
43
male
32,600
7000-8000'
51
male
58
male
43
male
31,300
8000-9000'
51
male
58
male
44
male
30,100
PROPANE
Front
Harman
Center Harman
Rear
Harman
Nominal Btu
Altitude
Injector Part No.
Injector Part No.
Injector Part No.
Input Rate
0-2000'
56
3-40-57356
71
3-40-57271
53
3-40-57753
40,000
2000-3000'
56
3-40-57356
71
3-40-57271
54
male
36,900
3000-4000'
56
3-40-57356
71
3-40-57271
54
male
36,900
4000-5000'
57
male
71
3-40-57271
54
male
35,400
5000-6000'
57
male
71
3-40-57271
55
male
32,600
6000-7000'
57
male
71
3-40-57271
55
male
32,600
7000-8000'
58
male
71
3-40-57271
56
3-40-57356
30,100
8000-9000'
58
male
71
3-40-57271
56
3-40-57356
30,100
THE CONVERSION SHALL BE CARRIED OUT
BY A MANUFACTURER'S AUTHORIzED REP-
RESENTATIVE IN ACCORDANCE WITH THE
REQUIREMENTS OF THE MANUFACTURER,
PROVINCIAL OR TERRITORIAL AUTHORITIES
HAVING jURISDICTION AND IN ACCORDANCE
WITH THE REQUIREMENTS OF THE CURRENT
EDITION OF CAN/CGA-B141.1 OR CAN/CGA-
B141.2 INSTALLATION CODES.
APPENDIX B
* When ordering injectors that have no Harman
part number, specify MALE or FEMALE and the
appropriate 2 digit injector number.
this appliance has been converted for use at an altitude of __________ft.
Orifice Sizes: Front ________ Center_________ Rear ________
input (Btu/hr) _________________
Manifold Pressure __________________
Fuel type _______________________
converted By _________________________________
Date of conversion _______________________________
