Specifications

177008-YIM-A-0406
Unitary Products Group 21
Optional Gas Heat
These gas-fired heaters have aluminized-steel or optional
stainless steel, tubular heat exchangers with spark ignition with
proven pilot.
All gas heaters are shipped from the factory equipped for
natural gas use. See Gas Heat Application Data Table.
For natural gas heating installations in locations requiring low
Nox emissions, Accessory model 1LN0406 must be used.
NOTE: Gas Heaters are shipped available for natural gas, but can be converted to L.P. with Kit Model No. 1NP0440 or 1NP0485 (2 Stage).
All furnaces meet the latest California seasonal efficiency requirements.
1. Based on 1075 Btu/Ft.
3
.
2. The air flow must be adjusted to obtain a temperature rise within the range shown.
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followed in all cases unless superseded by local codes or gas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 11. The
heating value of the gas may differ with locality. The value
should be checked with the local gas utility.
Figure 14: 2Side Entry Gas Piping
Figure 15: Bottom Entry Gas Piping
NOTE: Maximum capacity of pipe in cubic feet of gas per hour
based upon a pressure drop of 0.3 inch W.C. and 0.6
specific gravity gas.
NOTE: There may be a local gas utility requirement specifying a
minimum diameter for gas piping. All units require a 1/2
inch pipe connection at the entrance fitting. Line should
not be sized smaller than the entrance fitting size.
Table 10: GAS HEAT APPLICATION DATA
Gas Heat
Option
Input
Capacity
(MBH)
Output
Capacity
(MBH)
Available
On Models
Gas Rate
1
(Ft
3
/hr)
Temperature Rise °F At Full Input
2
Min. Max.
N04 50 40 3 TON 47 15 45
N06 75 60 4 TON 70 45 55
N08 100 80 3/5/6 TON 93 40/25/25 70/55/55
N10 125 100 4/5/6 TON 116 45/35/35 75/65/65
D06 75 61 3/4/5/6 TON 70 35/25/20/15 70/70/55/45
D10 115 92 3 TON 107 55 90
D10 125 101 4/5/6 TON 116 45/35/30 75/75/75
Table 11: Gas Pipe Sizing - CapacIty of Pipe
Length of
Pipe (ft.)
Nominal Iron Pipe Size
3/4 in. 1 in. 1-1/4 in.
10 278 520 1050
20 190 350 730
30 152 285 590
40 130 245 500
50 115 215 440
60 105 195 400
70 96 180 370
80 90 170 350
90 84 160 320
100 79 150 305