12. Provide adequate ventilation of the space occu-
pied by the heater (s) by an opening( s) for
ventilation air at the highest practical point com-
municating wit h the outdoors. The t otal
cross-sectional area shall be at least 1 in.2of free
area per 20,000 BTUH (111mm2per kW) of total
input rating of all equipment in the room when the
opening is communicating directly with the out-
doors or through v ertical duct(s ). The total
cross-sectional area shall be at least 1 in.2of free
area per 10,000 BTUH (222 mm2per kW) of total
input rating of all equipment in the room when the
opening is communicating with the outdoors
through horizontal duct(s).
13. In cold climates, and to mitigate potential freeze-
up, Raypak highly recommends the installation of
a motorized sealed damper to prevent the circula-
tion of cold air through the heater during the
non-operating hours.
TruSeal™ Combustion Air
In addition to the 13 previous steps, combustion air
may be ducted directly to the heater by using PVC,
CPVC or sealed single-wall galvanized ducting. The
duct will attach directly to the field installed air collar
located on the rear of the heater, using three or four
sheet metal screws (not supplied) equally positioned
around the circumference of the duct. The screws and
duct connection point should be sealed with RTV (not
supplied). TruSeal is generally used when damaging
contaminants are present in the mechanical room. All
ducting must be self-supported.
12
CAUTION: Use TruSe al combustion air if
damaging airborne contaminants are or may be
present in the heater area. See the Appendix of this
manual regarding air contamination.
8. Remove the debris screen (or cover panel for
model 1005) by removing the six screws holding it
in place.
9. Install the intake air collar using the six screws
removed in step 8 above.
10. Replace all the access panels.
11. Install combustion air direct vent in accordance
with Fig. 27 (horizontal) or Fig. 28 (vertical) of this
manual (pages 27 and 28, respectively).
Debris Screen
Fig. 11:Remove the Debris Screen
IntakeAir Collar
Fig. 12: Install the IntakeAir Collar
NOTE: Make sure that the air intake piping is
installed in a manner that allows full access to the air
filter without damage to the filter.