5120410-XIM-B-0216
24
Johnson Controls Unitary Products
Optional Gas Heat
These gas-fired heaters have aluminized-steel or optional
stainless steel, tubular heat exchangers with spark ignition.
Gas Piping
Proper sizing of gas piping depends on the cubic feet per hour
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followed in all cases unless superseded by local codes or gas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. Refer to the Pipe Sizing Table 19. The
heating value of the gas may differ with locality. The value
should be checked with the local gas utility.
Figure 23: Side Entry Gas Piping
Figure 24: Bottom Entry Gas Piping
OPTIONAL
COIL
GUARD
SHOWN
OPTIONAL
COIL
GUARD
SHOWN
Table 17: Gas Heat Minimum Supply Air Imperial
Size
(Ton)
Model
Heat
Size
Supply Air (CFM)
Cooling
Heating
Min
Max
Min
Max
090
(7.5)
DC
10
2250
3750
2250
3750
15
2250
3750
2250
3750
120
(10)
DC
15
3000
5000
3000
5000
20
3000
5000
3000
5000
150
(12.5)
DC
15
3750
6250
3750
6250
20
3750
6250
3750
6250
Table 18: Gas Heat Minimum Supply Air Metric
Size
(KW)
Model
Heat
Size
Supply Air (M
3
S)
Cooling
Heating
Min
Max
Min
Max
090
(26)
DC
10
1.06
1.76
1.06
1.76
15
1.06
1.76
1.06
1.76
120
(35)
DC
15
1.42
2.36
1.42
2.36
20
1.42
2.36
1.42
2.36
150
(44)
DC
15
1.76
2.95
1.76
2.95
20
1.76
2.95
1.76
2.95
