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Modulating Unitary Range
VA-LT206_11292016al
VENTING AND COMBUSTION AIR DUCTING
Outdoor Installation (ESH MODELS ONLY)
When a heater is to be mounted outdoors it must be installed in such a way that wind will have minimum effect
on its movement. This consideration is intended to eliminate undue stress on the gas flex connector. In all cases,
a fresh air hood must be used in conjunction with a vent terminal of the approved type, and all connections must
be sealed with a high temperature sealant that can withstand 400°F.
SEAL JOINTS
FRESH AIR INLET HOOD
SEAL JOINTS
VENT TERMINAL
Figure 29: Outdoor Installation
Note: that this heater is a sealed construction. If any services or repair is conducted in the future, gasket
materials should be inspected and replaced if found to be deteriorated.
GAS PIPING
•
The gas meter and service must be sufficiently large to supply gas to the connected building gas load
including the heating equipment and any other gas fired equipment. Additionally, the gas distribution
piping must be designed according to local and national ordinances. Generally (low pressure) systems
designed with a maximum ½ in W.C. total pressure drop meet this requirement
•
Gas supply pipe sizing must be in accordance with the National Fuel Gas Code, ANSI Z223.1 (NFPA 54)
in the US and CSA B149.1 and B149.2 Installation Codes in Canada.
•
Before connecting burners to the gas supply system, verify that high pressure testing of the system
has been completed. Failure to do so may expose the burner components to damaging high pressure,
requiring replacement of key components.
Flexible gas connectors of approved type must be installed as shown in Figure 30, in one plane, and without
sharp bends, kinks or twists. A smooth loop of approximately 12 in (30 cm) in diameter is best. Failure to install
the gas connection in the approved manner will result in a hazardous and potentially deadly situation due to the
movement of the heat exchanger and burner in the normal course of operation.
General Requirements
3" (7.62 cm) MAX.
DISPLACEMENT
SHUT-OFF VALVE
12"
AIR FLOW
DIRECTION
HEATER
MOVEMENT
0 - 180°
CORRECT POSITIONS
HEATER
MOVEMENT
HEATER
MOVEMENT
HEATER
MOVEMENT
HEATER
MOVEMENT
INCORRECT POSITIONS
WRONG
WRONG
Figure 30: Flexible Gas Connections