Installation Guide

2
UNIT HEATER APPLIANCES HORIZONTAL
INSTALLATION:
Horizontal commercial applications are for
buildings which are not attached to living
spaces. When venting through a sidewall
termination residential or commercial the
system shall be not less than 12" (.3m)
above the ground and 12" above the
highest snow fall. Terminate the system at
least 7’ (2.1 m) above a public walkway or
driveway and less than 6’ (1.8 m) from the
combustible intake of any appliance and no
less than 3’ (.9 m) from any other building
opening. For more information on
terminations. See National Fuel Gas Code
ANSIZ223 .1 and NFPA54. CAN/CSA-B148.1
or CAN/CSA-B149.2 Propane installations
code as applicable.
The total vent length from the appliance
flue collar to the outside termination shall
not be greater than the maximum specified
in the appliance manufacturer’s
instructions.
A horizontal installation shall have a slope
downwards of no less than ¼ " (6.4 mm)
every 12 "(305mm) to prevent excessive
condensate formation, ice buildup, or
blockage at any location in the assembly.
See appliance manufacturer’s installation
instructions for further details regarding
condensate drain fittings and pitch of the
system.
Pressure Vent Horizontal Installation
PRESSURE VENT INTO MASONRY CHIMNEY
AN IMPORTANT MESSAGE ABOUT RELINING
YOUR CHIMNEY
1. Have a professional installer throughly
clean, and install your new appliance
and relining system.
2. Determine condition of creosote
buildup in masonry flue, always clean
before relining. Any tar glaze creosote
buildup must be removed prior to
relining the chimney.
3. Determine condition of masonry
fireplace and chimney. See that they
meet code requirements. The chimney
should be checked for cracked, loose or
missing bricks, mortar, or other
materials that could inhibit a correct
installation of the liner system. Make
necessary repairs before relining.
4. The air space clearances between the
masonry chimney exterior and
combustible materials should be
checked to verify that the chimney is in
accordance with the clearance
specifications of 1) the NFPA; 2) other
applicable building codes; or 3) these
instructions. 0” clearnace if installed in
accordance with these instructions).
These requirements apply when a unit heater is
vented through a masonry chimney with
DuraFlex. Single appliance venting of a fan
assisted unit heater into a tile lined masonry
chimney (interior or exterior is prohibited). The
chimney must be lined with an insulated single
wall flexible vent lining system sized in
accordance with nationally accepted venting
tables. The DuraFlex system in a masonry
chimney should be insulated, because the
performance of the entire heating system will
be greatly enhanced with improved draft and
rduced condensation. The DuraFlex liner system
is held in place by the frame work at the top of