Circulating Air & Filters; Ductwork - Air Flow; Checking Duct Static - Goodman GKS9 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
4 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
w.c. 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, rec-
ommended 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 stan-
dard commercial compounds, special pipe dope must be used.
Shellac-based compounds resistant to the actions of liquefied pe-
troleum gases such as Gasolac
Crane ® are satisfactory.
Refer to the following illustration for typical propane gas installa-
tions.
First Stage
Regulator
200 PSIG
Maximum
Propane Gas Installation (Typ.)
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 Tubing Size, O.D. Type L
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
To convert to capacities at 15 psig settings - multiply by 1.130
To convert to capacities at 5 psig settings - multiply by 0.879
Propane Gas Piping Chart I
® , Stalactic ® , Clyde's
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 Single or Second Stage Regulator and Appliance*
Maximum Propane Capacities Listed are Based on 1/2" W.C. pressure drop at 11" W.C. 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
*Data in accordance with NFPA pamphlet NO. 54
D - A
UCTWORK
Duct systems and register sizes must be properly designed for the
CFM and external static pressure rating of the furnace. Design the
ductwork in accordance with the recommended methods of "Air
Conditioning Contractors of America" Manual D.
Install the duct system in accordance with Standards of the Na-
® or John
tional Board of Fire Underwriters for the Installation of Air Condi-
tioning, 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. Flexible joints may be used for supply
and return connections 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 be-
tween the unit and the utility room wall. Never use a room, closet,
or alcove as a return air chamber.
NOTE: Two side openings or a side opening and bottom opening
are required for airflow delivery of 1800 CFM and greater.
C D
HECKING UCT
Refer to your furnace rating plate for the maximum ESP (external
duct static) rating.
Total external static refers to everything external to the furnace cabi-
net. Cooling coils, filters, ducts, grilles, registers must all be con-
sidered when reading your total external static pressure. The sup-
3/4"
ply duct pressure must be read between the furnace and the cool-
ing coil. This reading is usually taken by removing the "A" shaped
7,500
4,200
block off plate from the end on the coil; drilling a test hole in it and
4,000
reinstalling the block off plate. Take a duct static reading at the test
3,700
hole. Tape up the test hole after your test is complete. The negative
3,400
3,100
pressure must be read between the filter and the furnace blower.
2,600
Too much external static pressure will result in insufficient air that
2,300
2,100
can cause excessive temperature rise. This can cause limit switch
1,900
tripping and heat exchanger failure.
1,700
To determine total external duct static pressure, proceed as fol-
1,500
lows;
1. With clean filters in the furnace, use a draft gauge (inclined
manometer) to measure the static pressure of the return duct
at the inlet of the furnace. (Negative Pressure)
2. Measure the static pressure of the supply duct. (Positive Pres-
sure)
3. The difference between the two numbers is .4" w.c.
27
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
Propane Gas Piping Chart II
XIII. CIRCULATING AIR & FILTERS
F
IR LOW
S
TATIC
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
237 448 913 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