Direct Air Intake Exhaust Duct Using 3-Inch Pvc Pipe (Indoor Installation) / Corrosive Vapors And Possible Causes - Pentair MASTERTEMP 125 Guide D'installation Et D'utilisation

Direct Air Intake Duct with 3-inch PVC Pipe (Indoor Installation)
For indoor heater installations where combustion air supply might be insufficient, the MasterTemp® 125
certified for a direct air intake duct using 3-inch PVC pipe. If outside air is drawn through 3" PVC duct directly into the
heater, PVC pipe can be installed in accordance with the following requirements:
The air intake opening MUST be installed at least 1 ft. above the roof line or normal snow levels for free air flow. The
Category I or III exhaust vent termination cap must have at least 3 ft. minimum vertical clearance from air intake duct
(See Figure 11 below).
Figure 11.
Note (*): Combustion Air Intake Duct Connection Kit (Call 1.800.831.7133 for part number) for all MasterTemp
Heater models can be purchased separately. See page 52 for parts list.
Each 90-degree elbow reduces the maximum horizontal PVC air intake duct run by 12 feet and each
45-degree elbow in the PVC air intake duct run reduces the maximum run by 6 feet. See the Table 5 above
for the maximum lengths using 90-degree elbows.
Corrosive Vapors and Possible Causes
Area
Chlorinated swimming
pools and spas
New construction and
remodeling areas
Table 5.
Rev. C 3/2019
NOTE
Likely Contaminants
Pool or spa cleaning chemicals. Acids,
such as hydrochloric or muriatic acid.
Glues and cements, construction
adhesives, paints, varnishes, and
paint and varnish strippers. Waxes and
cleaners containing calcium or sodium
chloride.
MASTERTEMP 125 Pool and Spa Heater Installation and User's Guide
Section 3. Installation Instructions
Combustion 3 in. PVC Pipe
Inlet Air Intake Duct Requirements*
Combustion Air Intake 3 in. Pipe
(Vertical or Horizontal)
No. of 90° Elbows Maximum Length in Feet (M)
0 70 ft. (21.3 M)
1 58 ft. (17.7 M)
2 46 ft. (14.0 M)
3 34 ft. (10.4 M)
4 22 ft. ( 6.7 M)
Table 4.
WARNING!
DO NOT USE PVC PIPE FOR FLUE
EXHAUST VENT. FLUE EXHAUST
VENT TEMPERATURES CAN BE IN
EXCESS OF 400° F. FLUE EXHAUST
VENT MUST BE CATEGORY I or
CATEGORY III METAL VENT.
CAUTION
Chemicals should not be stored near the
heater installation. Combustion air can
be contaminated by corrosive chemical
fumes which can void the warranty.
19
®
Heater is
® 125