AAON RZ Series, Installation Operation & Maintenance

Page: 85 / 112

85
Gas Heating
Verify the unit nameplate agrees with the
proper gas supply type and amount.
Gas piping shall be installed in accordance
with local codes, or in the absence of local
codes, installation shall conform to the
current (United States) National Fuel Gas
Code ANSI-Z223.1/NFPA 54 or the current
(Canada)
National Fuel & Propane
Installation Code CSA B149.1 or B149.2.
After verifying gas inlet pressure and
manifold pressure the service technician shall
time the gas flow rate through the gas meter
with a stopwatch to verify the gas input rate.
Unit nameplate input rate value has been
calculated at the altitude where the unit was
shipped. Above 2,000 ft the input rate is
adjusted 4% for every 1,000 ft.
Table 22 - RZ 45-140 ton Unit Gas Piping
Connections
RZ Small
Gas Input
(MBH) Connections
Quantity Size
540 1
2”
810 1
1080 1
1350 1
1620 1
2100 1
3”
2580 1
3060 1
Table 23 - RZ 145-240 ton Unit Gas Piping
Connections
RZ Medium
Gas Input
(MBH) Connections
Quantity Size
800 1
2-1/2”
1200 1
1600 1
2000 1
2400 1
3100 1
3”
3800 1
4500 1
See unit nameplate for unit gas heating
capacities or the Unit Rating Sheet, which
can be obtained from the AAON sales
representative.
Table 24 - Natural Gas Maximum Piping Capacities (ft
3
/hr)
- Specific Gravity = 0.6, Supply Pressure ≤ 0.5 psi, Pressure Drop = 0.5” w.c.
Pipe Size
Length of Pipe
20 ft 50 ft. 100 ft. 150 ft. 200 ft.
1-1/4” 950 580 400 325 280
1-1/2” 1460 900 620 500 430
2”
2750 1680 1150 950 800
2-1/2” 4350 2650 1850 1500 1280
3”
7780 4740 3260 2610 2240
4”
15900 9660 6640 5330 4560
FOR YOUR SAFETY
Read the entire gas heating
installation section of this manual
before beginning installation of the
gas heating section.
If you do not follow these instructions
exactly, a fire or explosion may result
causing property damage, personal
injury or loss of life.
WARNING