Installation Guide

17
Manual 58.
For satisfactory operation, propane gas pressure must be
10 inch WC at the furnace manifold with all gas appli ances
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 con tainer or
containers.
2. Proper pressure regulation. (Two-stage regulation is
recommended for both cost and effi ciency).
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 vaporiza tion,
recommended regulator settings, and pipe sizing is available
from most regulator manufacturers and propane gas suppliers.
Use a pipe thread compound that is approved for natural gas
and LP Gas.
Refer to the following illustration for typical propane gas in-
stallations and piping.
200 PSIG
Maximum
5 to 15 PSIG
(20 PSIG Max.)
Continuous
11" W.C.
Second Stage
Regulator
First Stage
Regulator
Propane Gas Installation (Typ.)
Figure 9
PROPANE GAS PIPING CHARTS
3/8" 1/2" 5/8" 3/4" 7/8" 1/2" 3/4"
10 730 1,700 3,200 5,300 8,300 3,200 7,500
20 500 1,100 2,200 3,700 5,800 2,200 4,200
30 400 920 2,000 2,900 4,700 1,800 4,000
40 370 850 1,700 2,700 4,100 1,600 3,700
50 330 770 1,500 2,400 3,700 1,500 3,400
60 300 700 1,300 2,200 3,300 1,300 3,100
80 260 610 1,200 1,900 2,900 1,200 2,600
100 220 540 1,000 1,700 2,600 1,000 2,300
125 200 490 900 1,400 2,300 900 2,100
150 190 430 830 1,300 2,100 830 1,900
175 170 400 780 1,200 1,900 770 1,700
200 160 380 730 1,100 1,800 720 1,500
Sizing Between First and Second Stage Regulator*
Maximum Propane Capacities listed are based on 2 psig pressure drop at 10 psig setting.
Capacities in 1,000 BTU/hour.
Nominal Pipe Size
Schedule 40
Tubing Size, O.D. Type L
Pipe or
Tubing
Length,
Feet
3/8" 1/2" 5/8" 3/4" 7/8" 1-1/8" 1/2" 3/4" 1" 1-1/4" 1-1/2"
10 39 92 199 329 501 935 275 567 1,071 2,205 3,307
20 26 62 131 216 346 630 189 393 732 1,496 2,299
30 21 50 107 181 277 500 152 315 590 1,212 1,858
40 19 41 90 145 233 427 129 267 504 1,039 1,559
50 18 37 79 131 198 376 114 237 448 910 1,417
60 16 35 72 121 187 340 103 217 409 834 1,275
80 13 29 62 104 155 289 89 185 346 724 1,066
100 11 26 55 90 138 255 78 162 307 630 976
125 10 24 48 81 122 224 69 146 275 567 866
150 9 21 43 72 109 202 63 132 252 511 787
200 8 19 39 66 100 187 54 112 209 439 665
250 8 17 36 60 93 172 48 100 185 390 590
Pipe or
Tubing
Length,
Feet
Nominal Pipe Size
Schedule 40
Tubing Size, O.D. Type L
Sizing Between Second Stage and Appliance Regulator*
Maximum Propane Capacities listed are based on 2 psig pressure drop at 10 psig setting.
Capacities in 1,000 BTU/hour.
CIRCULATING AIR
N EVER ALLOW THE PRODUCTS OF COMBUSTION , INCLUDING CARBON
MONOXIDE , TO ENTER THE RETURN DUCT WORK OR CIRCULATION AIR
SUPPLY .
WARNING
Duct systems and register sizes must be properly designed
for the CFM and external static pressure rat ing of the fur-
nace. Ductwork should be designed in accor dance 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. 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. For installations requiring
more than 1800 CFM, use a bottom return or two sided return.
Supply and return con nections to the furnace may be made
with fl exible joints to reduce noise transmission. To prevent
the blower from inter fering 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.