Thermolec Plenum Heater User Manual
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If a cooling coil is installed in the warm air plenum a
minimum distance of 3" or 7" is required between
the top of the cooling coil and the add-on heater
(depending from which side of the plenum
the add-on heater is inserted). (Please see Fig. 4)
In both cases, a minimum distance of 2" must be
kept between the top of the add-on heater
and the elbow, Tee or plenum-end take off
of the main supply duct.
The heater may be installed on any available side of the
plenum. An installation and service clearance of 28 inches is
required from the heater control box to a wall, partition or any
other obstruction.
If the heater is installed on the same side as the flue pipe a
minimum clearance of 10 inches must be maintained between
the flue pipe and the heater control box. (Please see Fig. 5)
Select the plenum side, which offers the most space for
installation and service.
VERY IMPORTANT
BAFFLES MUST ASSURE MAXIMUM AIR FLOW OVER THE HEATING ELEMENTS.
- Screw the baffles to bottom flanges of casing, as shown in Fig. 6.
- Cut baffles to size allowing only 1/8" clearance for insertion of heater.
AIR FLOW
All the air from the furnace must pass through the heater element. If the heater element casing is smaller than the
plenum the space between the plenum and the element casing must be blocked off with baffles. (Please see Fig. 7)
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