508093-01
Issue 2033
Page 26 of 59
Vent Piping Guidelines
NOTE:
Allied has approved the use of DuraVent
®
and
Centrotherm manufactured vent pipe and terminations as
an option to PVC. When using the PolyPro
®
by DuraVent
or InnoFlue
®
by Centrotherm venting system the vent
pipe requirements stated in the unit installation instruction
– minimum & maximum vent lengths, termination
clearances, etc. – apply and must be followed. Follow
the instructions provided with PoyPro by DuraVent and
InnoFlue by Centrotherm venting system for assembly
or if requirements are more restrictive. The PolyPro by
Duravent and InnoFlue by Centrotherm venting system
must also follow the uninsulated and unconditioned space
The A95UH1E / 95G1UHE can be installed as either a
Non-Direct Vent or a Direct Vent gas central furnace.
NOTE:
In Non-Direct Vent installations, combustion air is
taken from indoors and flue gases are discharged outdoors.
In Direct Vent installations, combustion air is taken from
outdoors and flue gases are discharged outdoors.
Intake and exhaust pipe sizing -- Size pipe according to
Table 10 and Table 11 through Table 13. Count all elbows
in side and outside the home. Table 10 lists the minimum
vent pipe lengths permitted. Table 11 through Table 13 lists
the maximum pipe lengths permitted.
Regardless of the diameter of pipe used, the standard roof
and wall terminations described in section Exhaust Piping
Terminations should be used. Exhaust vent termination
pipe is sized to optimize the velocity of the exhaust gas as
it exits the termination. Refer to Table 15.
In some applications which permit the use of several
different sizes of vent pipe, a combination vent pipe may
be used. Contact Allied Technical Services Department for
assistance in sizing vent pipe in these applications.
NOTE:
The exhaust collar on all models is sized to
accommodate 2” Schedule 40 vent pipe. In horizontal
applications, any transition to exhaust pipe larger than 2”
must be made in vertical runs of the pipe. Therefore a 2”
elbow must be added before the pipe is transitioned to
any size larger than 2”. This elbow must be added to the
elbow count used to determine acceptable vent lengths.
Contact the Application Department for more information
concerning sizing of vent systems which include multiple
pipe sizes.
Figure 21.
Capacity
Min. Vent Length*
030, 045, 070, 090, 110
15 ft or 5 ft plus 2 elbows or
10 ft plus 1 elbow
135 **
*Any approved termination may be added to the minimum
length listed.
** This gas furnace must have 3” to 2” reducing elbow
(supplied or field replacement Canadian kit) installed directly.
Table 10. Minimum Vent Pipe Lengths
Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.
IMPORTANT