Use the following steps to correctly size vent pipe diameter. Refer to Vent Pipe Size Determination Worksheet on page 53.
1 − Determine the vent termination and its corresponding equivalent feet value according to table 5.
2 − Determine the number of 90° elbows required for both indoor and outdoor (e.g. snow riser) use. Calculate the corresponding equivalent feet of vent pipe.
3 − Determine the number of 45° elbows required for both indoor and outdoor use. Calculate the corresponding equivalent feet of vent pipe.
4 − Determine the length of straight pipe required.
5 − Add the total equivalent feet calculated in steps 1 through 4 and compare that length to the maximum values given in table 6 for the proposed vent pipe di- ameter. If the total equivalent length required exceeds the maximum equivalent length listed in the appropri- ate table, evaluate the next larger size pipe.
TABLE 6
MINIMUM VENT PIPE LENGTHS
G61MP | MIN. EQUIV. | EXAMPLE | |
MODEL | VENT LENGTH | ||
| |||
|
|
| |
045, 070, |
| 5 ft. plus 2 elbows of 2", 2−1/2", 3" | |
071, 090, |
| ||
| or 4" diameter pipe | ||
091 |
| ||
|
| ||
|
|
| |
110, 111** | 15 ft.* | 5 ft. plus 2 elbows of 2−1/2" 3" or 4" | |
| diameter pipe | ||
|
| ||
135*** |
| 5 ft. plus 2 elbows of 3" or 4" | |
| diameter pipe | ||
|
| ||
|
|
|
*Any approved termination may be added to the minimum equivalent length listed.
**G61MP−48C−110, G61MP−60C−110 and G61MP−60C−111 must have 90° street ell (supplied or field replacment Canadian kit) installed directly into unit flue collar.
***G61MP−60D−135 must have 3" to 2" reducing ell (supplied or field replac- ment Canadian ki) installed directly into unit flue collar.
TABLE 7
MAXIMUM VENT PIPE LENGTHS
|
| MAXIMUM EQUIVALENT VENT | ||||
ALTITUDE | G61MP |
| LENGTH FEET |
| ||
|
|
|
| |||
MODEL | 2" | 2−1/2" | 3" | 4" | ||
| ||||||
|
| PIPE | PIPE | PIPE | PIPE | |
|
|
|
|
|
| |
| 045 | 59 | 65 | 77 | 234 | |
| 070 | 59 | 65 | 78 | 214 | |
| 071† | 59 | 65 | 78 | 214 | |
0 − 4500 | 090 | 26 | 42 | 72 | 204 | |
(0 − 1371 m) | 091† | 26 | 42 | 72 | 204 | |
| 110* | n/a | 32 | 72 | 179 | |
| 111*† | n/a | 32 | 72 | 179 | |
| 135**‡ | n/a | n/a | 61 | 160 | |
| 045 | 59 | 65 | 77 | 234 | |
| 070 | 59 | 65 | 78 | 214 | |
| 071† | 59 | 65 | 78 | 214 | |
4501−7500 | 090 | 26 | 42 | 72 | 204 | |
(1372−2286 m) | 091† | 26 | 42 | 72 | 204 | |
| 110* | n/a | 32 | 72 | 179 | |
| 111*† | n/a | 32 | 72 | 179 | |
| 135**‡ | n/a | n/a | 46 | 160 | |
| 045 | 59 | 65 | 77 | 234 | |
| 070 | 59 | 65 | 78 | 214 | |
| 071† | 59 | 65 | 78 | 214 | |
7501 − 10000 | 090 | 26 | 42 | 72 | 204 | |
(2287 − 3048 m) | 091† | 26 | 42 | 72 | 204 | |
| 110* | n/a | 32 | 72 | 179 | |
| 111*† | n/a | 32 | 72 | 179 | |
| 135**‡ | n/a | n/a | 46 | 160 | |
n/a −− Not allowed.
*G61MP−48C−110, G61MP−60C−110 and G61MP−60C−111must have 90° street ell (supplied or field replacment Canadian ki) installed directly into unit flue collar.
**G61MP−60D−135 must have 3" to 2" reducing ell (supplied or field replacment Canadian ki) installed directly into unit flue collar.
***90° elbows used in configuration of G61MP−60D−135 vent, must be lim- ited to 3" sweep elbows.
†On G61MP−071, −091 and −111 units, sweep elbows must be used for all 90° elbows in the venting system when 2", 2−1/2" or 3" vent pipe is used. Sweep elbows are recommended for use in vent systems of other G61MP units.
Page 19
