Trane Gas Unit Heaters Wartungshandbuch

32

 GTND-SVX01B-EN

1.

The combustion air system installation must be in 
accordance with the current edition of the National 
Fuel Gas Code-NFPA 54 or ANSI Z223.1 National Fuel 
Gas Code. In Canada, installation must be in 
accordance with CAN/CGA-B149.1 “Installation Code 
for Natural Gas Burning Appliances and Equipment” 
and CAN/CGA-B149.2“ Installation Code for Propane 
Burning Appliances and Equipment”.

2. The concentric vent box, inlet air screen, deflector disk, 

and vent terminal provided with the unit heater must 
be installed at the termination point of the combustion 
air/vent system. Refer to 

 through 

3. Each unit heater MUST have its own combustion air 

system. It MUST NOT be connected to other air intake 
systems.

4. Use single wall pipe constructed of 26 GA galvanized 

steel or a material of equivalent durability and 
corrosion resistance for the vent system. For 
installations in Canada, use corrosion resistant and 
gas-tight, listed vent pipe conforming with local 
building codes, or in the absence of local building 
codes, with current CAN/CGA-B149.1, “Installation 
Codes for Natural Gas Burning Appliances and 
Equipment” or CAN/CGA-B149.2, “Installation Codes 
for Propane Gas Burning Appliances and Equipment”. 

For installations in the United States, vent pipe 
approved for Category III appliances must be used 
between the appliance and the concentric vent box 
unless 33% of the vent run is vertical, then single wall 
galvanized vent pipe or double wall Type B vent pipe 
may be used between the appliance and the concentric 
vent box. A single length of double wall Type B vent 
pipe must be used to go through the concentric vent 
box and outside wall to the vent terminal.

5. Long runs of single wall combustion air piping passing 

through an unheated space may require insulating if 
condensation becomes noticeable.

6. The combustion air system must be installed to 

prevent collection of condensate. Pitch horizontal 
pipes downward 1/4 inch per foot toward the inlet cap 
to facilitate drainage. Vertical combustion air pipes 
should be piped as depicted in 

.

7.

The equivalent length of the combustion air system 
must not be less than 5 feet (1.5 m) and must not 
exceed 30 feet (9 m). Equivalent length equals the total 
length of straight pipe plus 5 feet (1.5 m) for each 90° 
elbow and 2.5 feet (0.76 m) for each 45° elbow.

8. Each slip joint must be secured with at least three 

corrosion resistant screws. Two full turns of 3M #425 
Aluminum Foil Tape or its equivalent must then be 
used to seal each joint. General Electric RTV-108, Dow-
Corning RTV-732 or an equivalent silicone sealant with 
a temperature rating of 500°F may be used instead of 
the tape.

9. For horizontal combustion air systems longer than 

5 feet (1.5 m), the system must be supported from 
overhead building structures at 4-foot (1.2-m) intervals 
in the U.S. and at 3-foot (0.91-m) intervals in Canada.

1.

Vent system installation must be in accordance with 
the current National Fuel Gas Code-NFPA 54 or ANSI