Thermo Pride Gas/Propane Furnace Induced Draft Highboy/Counterflow/Horizontal MHA1 - Manual (Page 23)

All installations and services must be performed by qualified service personnel.
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Installation, setup, and operation must be in accordance with the instruction
provided by the manufacture of the power venter. Thermo Products has provided
in the following section maximum and minimum vent lengths guidelines that must
also be followed.
Contact Field Controls for instructions for installing the SWGII vent system
IMPORTANT: No warranty will be made on behalf of the appliance manufacturer
with respect to the sidewall venting system installation or replacement. The
appliance manufacturer shall not be liable for any special, incidental, indirect, or
consequential damages. (Some jurisdictions do not allow exclusion or limitation
of incidental or consequential damages. The above limitations or exclusions may
not apply to you).
IMPORTANT: It is the installer’s responsibility to inform and demonstrate to the
user the correct operation and maintenance of the appliances explained in this
manual, the user’s information manual, and the sidewall vent manufacturer’s
manual.
1. Horizontal Size and Lengths for Horizontal Vents
The minimum sidewall vent length is two (2) feet of straight vent pipe with one (1)
elbow and one (1) adapter or transition to inducer. The maximum vent length and
permitted number of elbows are shown in the following table.
Table 3: Horizontal Size and Length for Sidewall Venting
SIZE
OF
Max. Length of Vent
Pipe (in Feet) With
EQUIVALENT
LENGTH MODEL NUMBER
OF FURNACE VENT
(In.)
1
ELBOW
2
ELBOWS
3
ELBOWS
OF VENT*
(Ft)
MHA1/MDA1-50 3 45 40 35 50
MHA1/MDA1-75
MHA1/MDA1-100
MHA1/MDA1-125 4 45 40 35 50
* Each elbow used is considered to be equivalent to 5 feet of straight vent pipe.