Sterling RF-90 Gas Heater User Manual


 
5
INSTALLATION
Do not install unit heaters in
corrosive or flammable atmospheres! Premature
failure of, or severe damage to the unit will
result!
Avoid locations where extreme
drafts can affect burner operation. Unit heaters
must not be installed in locations where air for
combustion would contain chlorinated,
halogenated or acidic vapors. If located in such
an environment, premature failure of the unit
will occur!
Since the unit is equipped with an automatic gas ignition
system, the unit heater must be installed such that the
gas ignition control system is not directly exposed to
water spray, rain or dripping water.
NOTICE: Location of unit heaters is related directly
to the selection of sizes. Basic rules are as follows:
MOUNTING HEIGHT: If the unit heater is installed in a
garage, it must be installed with a minimum clearance
above the floor of 18 inches (457mm).
AIR DISTRIBUTION: Direct air towards areas of
maximum heat loss. When multiple heaters are involved,
circulation of air around the perimeter is recommended
where heated air flows along exposed walls. Satisfactory
results can also be obtained where multiple heaters are
located toward the center of the area with heated air
directed toward the outside walls. Be careful to avoid
all obstacles and obstructions which could impede the
warm air distribution patterns.
Unit heaters should not be installed to maintain low
temperatures and/or freeze protection of buildings.
A minimum of 50°F (10°C) thermostat setting must
be maintained. If unit heaters are operated to maintain
lower than 50°F (10°C), hot flue gases are cooled inside
the heat exchanger to a point where water vapor (a flue
gas by-product) condenses onto the heat exchanger
walls. The result is a mildly corrosive acid that
prematurely corrodes the aluminized heat exchanger
and can actually drip water down from the unit heater
onto floor surface. Additional unit heaters should be
installed if a minimum 50°F (10°C) thermostat setting
cannot be maintained.
AIR FOR COMBUSTION: The unit heater shall be
installed in a location in which the facilities for ventilation
permit satisfactory combustion of gas, proper venting,
and the maintenance of ambient air at safe limits under
normal conditions of use. The unit heater shall be located
in such a manner as not to interfere with proper
circulation of air within the confined space. When
buildings are so tight that normal infiltration does not
meet air requirements, outside air shall be introduced
per Sections 1.3.4.2 and 1.3.4.3 of ANSI Z223.1 for
combustion requirements. A permanent opening or
openings having a total free area of not less than one
square inch per 5,000 BTU/Hr (1.5 kW) of total input
rating of all appliances within the space shall be
provided.
NOTICE: Unit Heater sizing should be based on heat
loss calculations where the unit heater output equals
or exceeds heat loss.
CLEARANCES: Each Gas Unit Heater shall be located
with respect to building construction and other equipment
so as to permit access to the Unit Heater. Clearance
between vertical walls and the vertical sides of the Unit
Heater shall be no less than 1 inch (25.4mm). However,
to ensure access to the control box and fan, a minimum
of 18" (457mm) is required for the fan, and control box
side. A minimum clearance of 1 inch (25.4mm) must be
maintained between the top of the Unit Heater and the
ceiling. The bottom of the Unit Heater must be no less
than 1 inch (25.4mm) from any combustible. The
distance between the flue collector and any combustible
must be no less than 1 inch (25.4mm). Also see AIR
FOR COMBUSTION and VENTING sections.
NOTICE: Increasing the clearance distances may
be necessary if there is a possibility of distortion or
discoloration of adjacent materials.
MOUNTING: The Unit Heater may be mounted with the
vent outlet, gas and electrical connections to the right
or left of the air moving fan. The Unit Heater is shipped
with the connections to the right of the fan when looking
in the direction of the air flow. If connections to the right
are required, remove hanger brackets from face of unit
and attach as pictured in Figure 3. If connections to the
left are required, invert the heater (180°), mount the
hanging brackets as above, and remove, invert, and
replace the control access panel and the air discharge
louvers.