66324-YIM-B-1004
Unitary Products Group
9
COMBUSTION DISCHARGE
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 or CAN/CGA
B149.1 or .2 should be followed in all cases unless super-
seded by local codes or gas company requirements. Refer to
Tables 5 and 6.
The heating value of the gas may differ with locality. The
value should be checked with the local gas utility.
NOTE:
There may be a local gas utility requirement specify-
ing a minimum diameter for gas piping. All units require a 1/2
inch pipe connection at the gas valve.
GAS CONNECTION
The gas supply line can be routed through the hole located
on the left side of the unit. Refer to Figure 5 to locate these
access openings. Typical supply piping arrangements are
shown in Figure 3.
Gas piping recommendations:
1.
A drip leg and a ground joint union must be installed in
the gas piping.
2.
When required by local codes, a manual shut-off valve
may have to 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.
TABLE 4: PROPANE
1
(LP) GAS APPLICATION DATA
AVAILABLE ON
MODELS
INPUT CAPACITY
(MBH)
2
OUTPUT CAPACITY
(MBH)
GAS RATE
3
FT.
3
/HR.
NUMBER OF
BURNERS
TEMP. RISE ×F AT FULL
INPUT
4
MIN.
MAX.
1-1/2, 2, 2-1/2, 3 TON
45
36
18
2
25
55
2 & 2-1/2 TON
70
56
28
3
30
60
3 TON
70
56
28
3
25
55
3-1/2, 4 & 5 TON
80
64
32
3
25
55
3 TON
90
72
36
4
30
60
3-1/2 TON
108
87
43
4
45
75
4 & 5 TON
108
87
43
4
30
60
4 & 5 TON
135
108
54
5
35
65
1.
Propane applications are accomplished by field installation of a Propane Conversion Accessory, Model 1NP0805.
2.
Heating capacity valid for elevations up to 2,000 feet above sea level. For elevations above 2,000 feet, rated capacity should be reduced by 4% for
each 1,000 feet above sea level.
3.
Based on 2500 BTU/Ft.
3
.
4.
The air flow must be adjusted to obtain a temperature rise within the range shown. Continuous return air temperatures should not be below 55°F.
