Circulating Air & Filters; Duct Work - Air Flow; Checking Duct Static - Goodman xMEC96 Series User Manual

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
Feet 3/8" 1/2"
10 730 1,700 3,200
20 500 1,100
30 400 920 2,000
40 370 850 1,700
50 330 770 1,500
60 300 700 1,300
80 260 610 1,200
100 220 540 1,000
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
C A & F
IRCULATING IR
D - A F
UCT WORK IR LOW
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 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 upflow installations requiring 1800 CFM or more, use either two side returns or bottom return or a
combination of side /bottom. 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 between
the unit and the utility room wall. Never use a room, closet, or alcove as a return air chamber.
C D S
HECKING UCT TATIC
Refer to your furnace rating plate for the maximum ESP (exter-
nal duct static) rating.
Total external static refers to everything external to the fur-
nace cabinet. Cooling coils, filters, ducts, grilles, registers must
all be considered when reading your total external static pres-
sure. The supply duct pressure must be read between the furnace and the cooling coil. This reading is usually taken by
removing the "A" shaped block off plate from the end on the coil; drilling a test hole in it and reinstalling the block off plate.
Take a duct static reading at the test hole. Tape up the test hole after your test is complete. The negative pressure must be
read between the filter and the furnace blower.
Too much external static pressure will result in insufficient air that can cause excessive temperature rise. This can cause
limit switch tripping and heat exchanger failure.
To determine total external duct static pressure, proceed as follows;
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 Pressure)
3. The difference between the two numbers is .4" w.c.
Example:
static reading from return duct = -.1" w.c.
static reading from supply duct = .3" w.c.
total external static pressure on this system = .4" w.c.
Nominal Pipe Size
Schedule 40
5/8" 3/4" 7/8" 1/2"
5,300 8,300 3,200
220 3,700 5,800 2,200
2,900 4,700 1,800
2,700 4,100 1,600
2,400 3,700 1,500
2,200 3,300 1,300
1,900 2,900 1,200
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
ILTERS
Sizing Between Second or Second Stage Regulator & 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
3/4"
Feet 3/8"
7,500
10 39
4,200
20 26
4,000
30 21
3,700
40 19
3,400
50 18
3,100
60 16
2,600
80 13
2,300
100 11
2,100
125 10
1,900
150 9
1,700
200 8
1,500
250 8
*Data in accordance wit h NFPA pamphlet No. 54
N
EVER ALLOW THE PRODUCTS OF COMBUSTION
,
MONOXIDE TO ENTER THE RETURN DUCT WORK OR CIRCULATION AIR
.
SUPPLY
27
T ubing Size, O.D. Typ e L
1/2" 5/8" 3/4" 7 /8" 1/2"
92 199 3 29 501 275
62 131 2 16 346 189
50 107 1 81 277 152
41 90 1 45 233 129
37 79 1 31 198 114
35 72 1 21 187 103
29 62 1 04 155 89
26 55 9 0 138 78
24 48 8 1 122 69
21 43 7 2 109 63
19 39 6 6 100 54
17 36 6 0 93 48
Propane Gas Piping Chart II
WARNING
Nom inal Pipe Size
Schedu le 40
3/4" 1" 1-1/4" 1-1/2"
567 1,07 1 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
,
INCLUDING CARBON