Sterling TD - Manual (Page 9)

9
INSTALLATION (continued)
CONVERSION OF ACCESS SIDE
The tubular duct furnace is built and shipped as left side
access – when looking in the direction of airfl ow, gas and
fl ue connections, control cabinet access are on the left
hand side and the combustion air inlet is on top. When
looking in the direction of airfl ow, you will be facing the
entering air side of the duct furnace. To convert the unit
to right side access:
1. Before suspending unit, fl ip the duct furnace 180
degrees widthwise (not rotated) so the gas and fl ue
connections are still on the entering air side of the
duct furnace.
2. Remove the four (4) screws holding the combustion
air inlet screen (now located on the bottom of the
unit); the screen and gasket can be removed and set
aside.
3. Remove the four (4) screws holding the block-off plate
(now located on the top of the unit); the plate and the
gasket can be removed and set aside.
4. Reinstall the block-off plate and its gasket on the
bottom of the unit using the four (4) screws.
5. Reinstall the combustion air inlet screen and its
gasket on the top of the unit using the four (4) screws.
It is not required to switch the combustion air inlet screen
and block-off plate locations once the unit has been
flipped. However, due to combustion noise, it is
recommended to keep the air inlet screen on top for
overhead installations.
NOTICE: If unit access side is converted, ensure
accessibility clearance is taken into account for the
new control cabinet end of the unit before suspension/
installation.
GAS PIPE SIZING
To avoid damage or possible
personal injury, do not connect gas piping to this
unit until a supply line pressure/leak test has been
completed. Connecting the unit before completing
the pressure/leak test may damage the unit gas
valve and result in a fi re hazard.
Do not rely on a shut-off valve to
isolate the unit while conducting gas pressure/
leak tests. These valves may not be completely
shut off, exposing the gas valve to excessive
pressure and damage.
PIPE SIZING
To provide adequate gas pressure to the gas unit heater,
size the gas piping as follows:
1. Find the cu. feet/hr. by using the following formula:
Cu. ft./hr. = Input BTU/Hr.
1000
2. Refer to Table 4. Match “Length of Pipe in Feet” with
appropriate “Gas Input - Cu. Ft./Hr.” fi gure. This fi gure
can then be matched to the pipe size at the top of the
column.
Example:
It is determined that a 67 foot (20.4m) run of gas pipe
is required to connect a 200 MBTU gas unit heater
to a 1,000 BTU/cu feet (0.29kW) natural gas supply.
200,000 BTU/Hr. = 200 Cu. ft./hr.
1,000 BTU/cu. feet
Using Table 4, a 1 inch pipe is needed.
NOTE: See General Safety Information section for
English/Metric unit conversion factors.
NOTICE: If more than one unit heater is to be served
by the same piping arrangement, the total cu. ft./hr.
input and length of pipe must be considered.
NOTICE: If the gas unit heater is to be fi red with LP
gas, consult your local LP gas dealer for pipe size
information.
NOTICE: HEATER INSTALLATION FOR USE WITH
PROPANE (BOTTLED) GAS MUST BE MADE BY
A QUALIFIED L.P. GAS DEALER OR INSTALLER.
HE/SHE WILL INSURE THAT PROPER JOINT
COMPOUNDS ARE USED FOR MAKING PIPE
CONNECTIONS; THAT AIR IS PURGED FROM LINES;
THAT A THOROUGH TEST IS MADE FOR LEAKS
BEFORE OPERATING THE HEATER; AND THAT IT IS
PROPERLY CONNECTED TO THE PROPANE GAS
SUPPLY SYSTEM.
Before any connection is made to the existing line
supplying other gas appliances, contact the local gas
company to make sure that the existing line is of adequate
size to handle the combined load.