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
or John Crane ® are satisfactory.
Refer to the following illustration for typical propane gas
installations and piping.
First Stage
Regulator
200 PSIG
Maximum
Propane Gas Installation (Typ.)
P G P C
ROPANE AS IPING HARTS
Sizing Between First and Second Stage Regulator*
Maximum Propane Capacities listed are based on 2 psig pressure drop at 10 psig setting.
Capacities in 1,000 BTU/hour.
Pipe or
Tubing Size, O.D. Type L
Tubing
Length,
3/8" 1/2"
Feet
10 730 1,700
20 500 1,100
30 400 920
40 370 850
50 330 770
60 300 700
80 260 610
100 220 540
125 200 490
150 190 430
175 170 400
200 160 380
® , Stalactic
5 to 15 PSIG
(20 PSIG Max.)
Continuous
11" W.C.
Second Stage
Regulator
Nominal Pipe Size
Schedule 40
5/8" 3/4" 7/8" 1/2"
3,200 5,300 8,300 3,200
2,200 3,700 5,800 2,200
2,000 2,900 4,700 1,800
1,700 2,700 4,100 1,600
1,500 2,400 3,700 1,500
1,300 2,200 3,300 1,300
1,200 1,900 2,900 1,200
1,000 1,700 2,600 1,000
900 1,400 2,300 900
830 1,300 2,100 830
780 1,200 1,900 770
730 1,100 1,800 720
Sizing Between First and Second Stage Regulator*
Maximum Propane Capacities listed are based on 2 psig pressure drop at 10 psig setting.
Capacities in 1,000 BTU/hour.
Pipe or
Tubing
Length,
3/8"
Feet
10 39
20 26
30 21
40 19
50 18
60 16
80 13
100 11
125 10
150 9
200 8
250 8
X. CIRCULATING AIR AND FILTERS
N
EVER ALLOW THE PRODUCTS OF COMBUSTION, INCLUDING CARBON
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
® , Clyde's ®
the National Board of Fire Underwriters for the Installation of Air
Conditioning, Warm Air Heating and Ventilating Systems.
Pamphlets No. 90A 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
3/4"
can be viewed for visual light inspection or such that a sampling
7,500
probe can be inserted into the airstream. The access panel must
4,200
be made to prevent air leaks when the furnace is in operation.
4,000
3,700
When the furnace is heating, the temperature of the return air
3,400
310
entering the furnace must be between 55°F and 100°F.
2,600
2,300
When a furnace is installed so that supply ducts carry air circulated
2,100
by the furnace to areas outside the space containing the furnace,
1,900
1,700 the return air shall also be handled by a duct sealed to the furnace
1,500
casing and terminating outside the space containing the furnace.
20
Tubing Size, O.D. Type L
1/2" 5/8" 3/4" 7/8" 1-1/8" 1/2"
92 199 329 501 935 275
62 131 216 346 630 189
50 107 181 277 500 152
41 90 145 233 427 129
37 79 131 198 376 114
35 72 121 187 340 103
29 62 104 155 289 89
26 55 90 138 255 78
24 48 81 122 224 69
21 43 72 109 202 63
19 39 66 100 187 54
17 36 60 93 172 48
Ductwork - Air
WARNING
Nominal Pipe Size
Schedule 40
3/4" 1" 1-1/4" 1-1/2"
567 1,071 2,205 3,307
393 732 1,496 2,299
315 590 1,212 1,858
267 504 1,039 1,559
237 448 91 1,417
217 409 834 1,275
185 346 724 1,066
162 307 630 976
146 275 567 866
132 252 511 787
112 209 439 665
100 185 390 590