3.
A type B-1 vent or masonry chimney liner shall terminate
above the roof surface with a listed cap or a listed roof
assembly in accordance with the terms of their respective
listings and the vent manufacturer's instructions.
4.
Do not install a manual damper, barometric draft regulator, or
flue restrictor between the unit heater and the chimney.
5.
If type B-1 double-wall vent is used inside a chimney, no other
appliance can be vented into the chimney. Outer wall of type
6.
Insulation for the flexible vent pipe must be an encapsulated
fiberglass sleeve recommended by the flexible vent pipe
manufacturer.
7.
The space between liner and chimney wall should NOT
be insulated with puffed mica or any other loose granular
insulating material.
8.
used as liners, the chimney must be rebuilt to accommodate
one of these methods or some alternate approved method
must be found to vent the appliance. When inspection
reveals that an existing chimney is not safe for the intended
purpose, it shall be rebuilt to conform to nationally
recognized standards, lined or relined with suitable materials
or replaced with a gas vent or chimney suitable for venting
unit heaters. The chimney passageway must be checked
periodically to ensure that it is clear and free of obstructions.
G – REMOVAL OF UNIT FROM COMMON VENT
In the event that an existing unit heater is removed from a venting
system commonly run with separate gas appliances, the venting
system is likely to be too large to properly vent the remaining
attached appliances. The following test should be conducted while
each appliance is in operation and the other appliances are not in
operation, yet remain connected to the common venting system.
If the venting system has been installed improperly, the system
must be corrected.
1.
Seal any unused openings in the common venting system.
2.
Visually inspect the venting system for proper size and
horizontal pitch. Determine there is no blockage or
restriction, leakage, corrosion, or other deficiencies which
could cause an unsafe condition.
3.
If practical close all building doors and windows and all
doors between the space in which the appliances remaining
connected to the common venting system are located and
other spaces of the building. Turn on clothes dryers and any
appliances not connected to the common venting system.
Turn on any exhaust fans, such as range hoods and bathroom
exhausts, so they will operate at maximum speed. Do not
operate a summer exhaust fan. Close fireplace dampers.
4.
Follow the lighting instructions. Place the appliance being
inspected in operation. Adjust thermostat so appliance will
operate continuously.
5.
6.
7.
NOTE Local codes may supersede any of the above provisions.
E-7
Compact Unit Heater
Operating Instructions and Owner's Manual
Test for spillage at the draft hood relief opening after flve
minutes of main burner operation. Use the flame of a match
or candle, or smoke from a cigarette, cigar, or pipe.
After it has been determined that each appliance remaining
connected to the common venting system properly vents
when tested as outlined above, return doors, windows,
appliance to their previous condition of use.
If improper venting is observed during any of the above
tests, the common venting system must be corrected. The
common venting system should be resized to approach the
minimum size as determined by using the appropriate tables
in Appendix G in the current standards of the National Fuel
Gas Code, ANSI Z223-1 in the U.S.A. and the appropriate
Category I Natural Gas and Propane appliances venting sizing
tables in the current standards of the CSA B149.1 Natural Gas
and Propane Installation Code in Canada.