Johnson Controls ZL Series Installation Manual page 43

Optional gas heat
These gas-fired heaters have aluminized-steel or
optional stainless steel, tubular heat exchangers
with spark ignition.
Gas piping
Correct sizing of gas piping depends on the ft³/h
of gas flow required, specific gravity of the gas and
the length of run. National Fuel Gas Code Z223.1
(in U.S.A.) or the current Gas Installation Codes
CSA-B149.1 (in Canada) should be followed in all
cases unless superseded by local codes or gas utility
requirements. See the pipe sizing Table 18. The
heating value of the gas may differ with locality. The
value should be checked with the local gas utility.
Figure 20: Side entry gas piping
Note: Routing of gas piping must not interfere
with the flue or heat compartment access.
Table 18: Gas pipe sizing - capacity of pipe
Length of pipe (ft)
3/4 in.
10 278
20 190
30 152
40 130
50 115
60 105
70 96
80 90
90 84
100 79
Nominal iron pipe size
1 in. 1-1/4 in.
520 1050
350 730
285 590
245 500
215 440
195 400
180 370
170 350
160 320
150 305
Johnson Controls Ducted Systems
Note: Maximum capacity of pipe in cubic feet
of gas per hour based upon a pressure drop of
0.3 in. W.C. and 0.6 specific gravity gas.
Note: There may be a local gas utility
requirement specifying a minimum diameter
for gas piping. Units require either a ½ in. or
3/4 in. pipe connection at the entrance fitting.
Line should not be sized smaller than the
entrance fitting size.
Table 19: Gas heat supply air
Model Gas heat
Opt.
(ton) description
Low
ZL08 (7.5) Med
High
Low
ZL09 (8.5) Med
High
Low
ZL12 (10) Med
High
Low
ZL14 (12.5) Med
High
Gas connection
The gas supply line can be routed within the space
and roof curb, exiting through the unit's basepan.
See Figure 11 through Figure 12 for the gas piping
inlet location. Typical supply piping arrangements
are shown in Figure 20. All pipe nipples, fittings, and
the gas cock are field supplied.
Gas piping recommendations
1. A drip leg and a ground joint union must be
installed in the gas piping.
2. Where required by local codes, a manual shut-
off valve must be installed outside of the unit.
3. Use wrought iron or steel pipe for all gas lines.
Pipe dope should be applied sparingly to male
threads only. If local codes allow the use of a
flexible gas appliance connector, always use a
new listed connector. Do not use a connector
which has previously serviced another gas
appliance.
Installation Manual ZL Series 7.5- 12.5 Ton 60 Hertz R-410A
Supply air (cfm)
Heating
Min Max
D 2260 3700
E 2260 3700
F 2260 3790
D 2570 4210
E 2560 4300
F 2550 4290
D 3030 4940
E 3020 4940
F 2990 5010
D 3700 6350
E 3790 6270
F 3780 6170
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