Circulating Air And Filters - Goodman GMH8 Installation Instructions Manual

A gas detecting warning system is the only reliable way to detect a
propane gas leak. Rust can reduce the level of odorant in propane
gas. Do not rely on your sense of smell. Contact a local propane
gas supplier about installing a gas detecting warning system. If
the presence of gas is suspected, follow the instructions on Page
3 of this manual.
All propane gas equipment must conform to the safety standards
of the National Board of Fire Underwriters, NBFU Manual 58.
For satisfactory operation, propane gas pressure must be 11 inch
WC at the furnace manifold with all gas appliances in operation.
Maintaining proper gas pressure depends on three main factors:
1. Vaporization rate, depending on temperature of the liquid,
and "wetted surface" area of the container or containers.
2. Proper pressure regulation. (Two-stage regulation is
recommended for both cost and efficiency).
3. Pressure drop in lines between regulators, and between
second stage regulator and the appliance. Pipe size will
depend on length of pipe run and total load of all
appliances.
Complete information regarding tank sizing for vaporization,
recommended regulator settings, and pipe sizing is available
from most regulator manufacturers and propane gas suppliers.
Since propane gas will quickly dissolve white lead and most
standard commercial compounds, special pipe dope must be
used. Shellac-based compounds resistant to the actions of
liquefied petroleum gases such as Gasolac ®, Stalactic ®, Clyde's ®
or John Crane ® are satisfactory.
Refer to the following illustration for typical propane gas
installations and piping.
First Stage
Reg
5 to 15 P$1G
(20 P$1G Max,)
200 PSIG _
Maximum
!
Continuous
11" W.C.
Second Stage
Propane Gas Installation (Typ.)
PROPANE GAS PIPING CHARTS
Sizing Between First and Second Stage Regulator*
Maximum Propane Capacities listed are based on 2 psig pressure drop at 10 psig setting.
Capacities in 1,O0O BTU/hour
Pipe or
Tubing Tubing Size, O.D. Type L
Length,
Feet 3/8" 1/2" 5/8" 3/4"
10 730 1,700 3,200 5,300
20 500 1,100 2,2g0 3,700
30 400 920 2,000 2,900
40 370 850 1,700 2,700
50 330 770 1,5g0 2,400
60 300 700 1,300 2,200
80 260 610 1,2g0 1,900
100 220 540 1,000 1,700
125 200 490 900 1,400
150 190 430 830 1,300
175 170 400 780 1,200
200 160 380 730 1,100
Nominal Pipe Size
Schedule 40
7/8" 1/2" 3/4"
8,300 3,200 7,500
5,800 2,200 4,200
4,700 1,800 4,000
4,100 1,600 3,700
3,700 1,500 3,400
3,300 1,300 310
2,900 1,200 2,600
2,600 1,O0O 2,300
2,30g 900 2,100
2,10g 830 1,900
1,gog 770 1,700
1,8og 720 1,500
Sizing Between First and Second Stage Regulator*
Maximum Propane Capacities listed are based on 2 psig pressure drop at 10 psig setting¸
t 000 BTU/hour
Pipe or Tubing Size, OD Type L Nomina_ Pipe Size
Tubing Schedule 40
Length,
Feet 3/8" 1/2" 5/8" 3/4" 7/8" 1-I/8" 1/2" 3/4" 1" 1-1/4" 1-1/2"
10 39 92 199 329 501 935 275 567 1T871 2T205 3,387
20 26 62 131 216 346 638 189 393 732 1.496 2,289
30 21 58 107 18t 277 588 152 315 590 1.212 1,858
40 19 41 98 I45 233 427 129 267 504 1.039 1,559
50 18 37 79 t31 198 376 114 237 448 91 1,4t7
60 16 35 72 121 187 348 103 217 409 834 1,275
80 13 29 62 104 155 289 89 185 346 724 1,066
100 11 28 55 90 138 255 78 162 307 630 976
125 18 24 48 81 122 224 69 I46 275 567 866
150 9 21 43 72 109 282 63 132 252 511 787
280 8 19 39 66 100 187 54 112 209 439 665
250 8 17 36 68 93 172 48 100 185 390 598
X. CIRCULATING AIR AND FILTERS
Ductwork - Air
&WARN,NG !
NEVER ALLOW THE PRODUCTS OF COMBUSTION, INCLUDING CARBON I
I
MONOXIDE, TO ENTER THE RETURN DUCTWORK OR CIRCULATION AIR SUPPLY.
Duct systems and register sizes must be properly designed for
the CFM and external static pressure rating of the furnace.
Ductwork should be designed in accordance with the
recommended methods of "Air Conditioning Contractors of
America" Manual D.
A duct system must be installed in accordance with Standards of
the National Board of Fire Underwriters for the Installation of Air
Conditioning, Warm Air Heating and Ventilating Systems.
Pamphlets No. 9OA and 90B.
A closed return duct system must be used, with the return duct
connected to the furnace. NOTE: Ductwork must never be attached
to the back of the furnace. Supply and return connections to the
furnace may be made with flexible joints to reduce noise
transmission. To prevent the blower from interfering with
combustion air or draft when a central return is used, a connecting
duct must be installed between the unit and the utility room wall. A
room, closet, or alcove must not be used as a return air chamber.
When the furnace is used in connection with a cooling unit, the
furnace should be installed in parallel with or on the upstream
side of the cooling unit to avoid condensation in the heating
element. With a parallel flow arrangement, the dampers or other
means used to control the flow of air must be adequate to prevent
chilled air from entering the furnace and, if manually operated,
must be equipped with means to prevent operation of either unit
unless the damper is in the full heat or cool position.
When the furnace is installed without a cooling coil, it is
recommended that a removable access panel be provided in the
outlet air duct. This opening shall be accessible when the furnace
is installed and shall be of such a size that the heat exchanger
can be viewed for visual light inspection or such that a sampling
probe can be inserted into the airstream. The access panel must
be made to prevent air leaks when the furnace is in operation.
When the furnace is heating, the temperature of the return air
entering the furnace must be between 55°F and 100°R
When a furnace is installed so that supply ducts carry air circulated
by the furnace to areas outside the space containing the furnace,
the return air shall also be handled by a duct sealed to the furnace
casing and terminating outside the space containing the furnace.
2O