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These units are designed to either use house air or outside
air for combustion. For houses concerned with negative
pressure from appliances using house air, installing the
make-up air kit is recommmended. By doing so this
appliance will operate as a direct vent using no house air
for combustion.
The causes of negative pressure to a house can include
the following:
•
Stack effect in the building.
•
Exhaust only appliances (mechanically and atmospher-
ically vented).
•
Inadequate make-up air (which is increasingly more
prevalent in new construction).
NOTE:
Heat-N-Glo assumes no responsibility for the
improper performance of the fireplace system or other
appliances caused by inadequate draft due to
environmental conditions, down drafts, tight sealing
construction of the structure, or mechanical exhausting
devices which create a negative air pressure within the
structure where the fireplace is located.
It is recommended that the building be mechanically or
passively balanced to allow atmospherically vented
appliances, such as gas fireplaces, to draft properly. If the
home experiences negative pressure or is likely to
experience negative pressure, connection to an outside
air source is mandatory.
A 4 inch side collar (see Figure 9) found in your termination
kit, must be installed on the fireplace by removing the cover
plate and attaching the side collar to the outer wrap as
shown (see Figure 10).
Step 4. Negative Pressure Make-up Air
Termination of the Fresh Air Duct:
The fresh air duct can be terminated directly adjacent to
or directly above the exhaust termination but, must be no
closer than 3 feet below and a minimum of 12” above the
grade.
Figure 11. Duct Termination Assembly
!
WARNING: IN A NEGATIVE PRESSURE
CONDITION (LIKELY TO OCCUR IN NEW
HOMES THAT DO NOT HAVE ADEQUATE MAKE-
UP AIR) THE OUTSIDE AIR KIT MUST BE IN-
STALLED TO OBTAIN PROPER PERFORMANCE
AND TO HELP PREVENT SPILLAGE OF COMBUS-
TION GASES.
Figure 9. Side Collar
Figure 10. Fresh Air Kit
REMOVE
COVER PLATE
ATTACH
SIDE COLLAR
Using 4 inch Class-I flex vent make the connection to the
outside of the house, terminating with the duct termination
included in the termination kit. The fresh air make-up vent
run should not exceed 25 feet (see Figure 11).
DUCT
TERMINATION
RAIN CAP
WALL
CAULKING