Part number 550-142-903/1016
32
&IGURE GV90+ venting and air piping — OPTIONS and PIPING LIMITS
Vent length affects boiler input — the boiler automatically derates to compensate for pressure loss through the vent.
See the derate values given in Figure 109, page 103. The longer the vent, the more the input is reduced.
GV90+ Model
Maximum vent and air pipe lengths
(Minimum length for all applications is 2 feet)
(All applications include allowance for the termination fittings)
DIRECT VENT
(combustion air piped to boiler from outside)
DIRECT EXHAUST
(combustion air from inside)
SIDEWALL
termination
VERTICAL
termination
SIDEWALL
termination
VERTICAL
termination
Weil-McLain
vent/air cap
3” PVC
Separate pipes
3” PVC
Concentric
[Note 1]
3” PVC
Separate pipes
3” PVC
Concentric
[Note 1]
3” PVC
Coupling or
W-M Cap
3” PVC
Coupling
See page 37 See page 39 See page 41 See page 43 See page 45 See page 51 See page 53
Max.
Length
(feet)
Max.
Length
(feet)
Max.
Length
(feet)
Max.
Length
(feet)
Max.
Length
(feet)
Max.
Length
(feet)
Max.
Length
(feet)
-3
100 100 100 100 100 100 100
-4
100 100 100 100 100 100 100
-5
100 100 100 100 100 100 100
-6
100 100 100 100 100 100 100
Equivalent feet for elbows — deduct from maximum equivalent length of piping (does not apply to termination fittings)
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GV90+ Series 2 GAS-FIRED WATER BOILER — Boiler Manual
Venting & air — general (cont.)