Goodman GMP Installation & Operating Instructions Manual page 8

SIZE*
10
1/2 132
3/4 278
1 520
1 1/4 1050
1 1/2 1600
* Nominal size of Iron Pipe in inches.
After the length of pipe has been determined, select the pipe size that will provide the minimum cu-
bic feet per hour of gas flow for the required input of the appliance. In the case where more than
one appliance utilizes the same supply pipe be sure to consider the sum of all appliances. The cu-
bic feet required for the appliances should be determined using the following formula;
Cubic feet per hour of gas required = Gas input of appliance (Btu/hr) / heating value of gas(Btu/hr)
The gas input of the appliance is marked on the specification plate. The heating value of the gas
may be determined by contacting the gas utility or gas supplier.
If the local utility permits the use of a listed flexible gas connector, ALWAYS USE A NEW
FLEXIBLE CONNECTOR. DO NOT USE A FLEXIBLE GAS CONNECTOR WHICH HAS
SERVICED ANOTHER APPLIANCE. AFTER A PERIOD OF TIME THESE LINES MAY BECOME
BRITTLE AND WITH THE DISCONNECTION AND RECONNECTION CAN DEVELOP LEAKS.
The circulating air supply may be taken from; 1) outside the building, 2) return ducts from several
rooms, 3) central return, 4) any combination of the above.
When a cooling coil is not installed it is recommended that the supply duct have an access panel
so the heat exchanger can be viewed. This panel shall be of sufficient size to permit the entrance
of a light or probe to assist in the observation of the heat exchanger integrity or sampling the air
stream. It should sealed to prevent air leakage during normal operation.
Return air from one dwelling unit shall not be discharged into another dwelling unit.
DO NOT take return air from bathrooms, kitchens, furnace rooms, garages, utility or laundry rooms
or cold areas. If outside air is utilized it should not be taken from within 10 feet of an appliance vent
outlet, a vent opening or a plumbing drainage system or the discharge from an exhaust system
unless the outlet is three (3) feet above the outside air inlet. DO NOT take return air from areas
where it can pick-up objectionable odors, fumes, or flammable vapors.
IO137
20 30
92 73
190 152
350 285
730 590
1100 890
CIRCULATING AIR SUPPLY AND RETURN AIR
NEVER LAY THIS FURNACE ON IT'S FRONT OR REAR
40 50
63 56
130 115
245 215
500 440
760 670
CAUTION
WARNING
CAUTION
8
60 70 80
50 46 43
105 96 90
195 180 170
400 370 350
610 560 530