General Venting; Barometric Damper Location - Lochinvar EW150 Installation & Service Manual

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General venting

General
Vent installations for connection to gas vents or chimneys
must be in accordance with Part 7, "Venting of Equipment,"
of the latest edition of the National Fuel Gas Code, ANSI
Z223.1, in Canada, the latest edition of CAN/CGA
B149 Installation Code for Gas Burning Appliances and
Equipment or applicable provisions of the local building
codes.
Conventionally vented applications where outside air is
used must have adequate combustion and ventilation air
supplied to the mechanical room in accordance with the
latest edition of the National Fuel Gas Code, ANSI Z223.1,
in Canada, the latest edition of CAN/CGA B149 Installation
Code for Gas Burning Appliances and Equipment, or
applicable provisions of the local building codes.
The distance of the vent terminal from adjacent buildings,
windows that open and building openings MUST comply
with the latest edition of the National Fuel Gas Code,
ANSI Z223.1, in Canada, the latest edition of CAN/CGA
B149 Installation Code for Gas Burning Appliances and
Equipment.
Vent connection is made directly to the top of the appliance.
No additional draft diverter is required. The connection
from the appliance vent to the stack must be made as direct
as possible.
The negative draft in conventional vent installations must
be within the range of a negative 0.02 to 0.05 inches water
to ensure proper operation. All draft readings are made
while appliance is in stable operation (approximately 2 to
5 minutes).
Locate units as close as possible to chimney or gas vent.
See the vent material requirements for each of the specific
venting options. Conventional venting systems use Type
"B" double wall vent material. Direct vent systems have
specific vent kits and material requirements noted for each
application.
Any vent materials not provided or specified must be
listed by a nationally recognized test agency for use as vent
material.
Avoid long horizontal runs of the vent pipe, 90° elbows,
reductions and restrictions. Horizontal portions of the
venting system shall be supported to prevent sagging.
Horizontal runs must slope upwards not less than 1/4 inch
per foot (21 mm per meter) from the appliance to the vent
terminal. Follow manufacturers instructions.
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Installation & Service Manual
The weight of the venting system must not rest on the
appliance. Adequate support of the venting system must be
provided in compliance with local codes and other applicable
codes. All connections should be secured with rustproof sheet
metal screws.

Barometric damper location

Any venting system option that requires a barometric damper
must adhere to the following directions for optimum performance.
The preferred location for the barometric damper is in a tee or
collar installed in the vertical pipe rising from the appliance's flue
outlet. The barometric damper MUST NOT be installed in a bull
head tee installed on the appliance's flue outlet. The tee or collar
containing the barometric damper should be approximately
three feet vertically above the connection to appliance's flue
outlet. This location ensures that any positive velocity pressure
from the appliance's internal combustion fan is dissipated and
the flue products are rising due to buoyancy generated from the
temperature of the flue products. Adjust weights on damper to
ensure that draft is maintained within the specified range.
Figure 2-1 Vent Termination from a Peaked Roof 10" or
Less from Ridge
Figure 2-2 Vent Termination from a Peaked Roof 10" or
More from Ridge