Carrier Aero 39MN Series Installation, Start-Up And Service Instructions Manual page 168

NOTE: See the section,
Vented Duct Furnaces," on page 165 for
vent pipe diameters.
Category III Horizontal Furnace Venting (through Sidewall)
(Only dedicated furnace venting permitted. Each furnace must have its own individual vent pipe and terminal.)
IMPORTANT: When pressure testing at
less, close the manual shut-off valve on the appliance
before testing. When pressure testing the gas supply
line at 1 / psig or greater, close the manual shut-off
2
valve and disconnect the heater from supply line to be
tested. Cap or plug the supply line.
PRESSURE
REGULATOR
GAS
SUPPLY
"Vertically
AIR-HANDLING UNIT
Fig. 139 — Indoor Horizontal Venting
1 / psig or
2
MAX. 13.5 in. wg
UNIT 1
Fig. 140 — Inlet Pressure for Multiple Heaters
GAS SUPPLY
GAS SUPPLY
LINE
3 IN.
MIN.
SEDIMENT
Fig. 141 — Sediment Trap, Shut-Off Valve, and Union
5 FT. (1.52 M) MIN.
50 FT. (15.35 M) MAX. EQUIV. LENGTH
1/4 IN. (6 mm) PITCH PER
1 FT. (305 mm) HORIZONTAL
RUN
SEE VENT PIPE
DIAMETER TABLE
FOR
VENT DIAMETER
FIELD FABRICATED
VENT TO EACH
EXHAUST CONNECTION
CONDENSATE
DRAIN
All field gas piping must be pressure and leak-tested
prior to operation. Never use an open flame to check for
leaks as combustion and personal injury may result. Use
a soap solution or other leak detecting solution.
MINIMUM INLET PRESSURE
REQUIRED AT LAST HEATER
UNIT 2
LINE
GROUND JOINT
MANUAL GAS
UNION WITH
SHUT-OFF VALVE
BRASS SEAT
TO CONTROLS
PLUGGED
1/8 IN. NPT TEST
GAGE CONNECTION
TRAP
168
1 FT.
MIN.
LISTED VENT
TERMINAL
3 FT. MIN. (0.91 m) ABOVE
CONDENSATE
HIGHEST SNOWFALL
DRAIN
EXTERIOR WALL
WARNING
UNIT 3
a39-4397