Venting Options; Installation; Table B. Flue Sizes - Lochinvar COPPER-FIN CW 645 Designer's Manual

Lochinvar
must be consistent with the National Fuel
NOTE:
Gas Code Z223.1 or in Canada, the latest
A vent system should
edition of CGA Standard B149 Installation
never be sized based
Code for Gas Burning Appliances and
only on the vent
Equipment.
connection diameter of
the appliance. For proper

VENTING OPTIONS

vent design and sizing,
Conventional Venting
please consult the
A conventional venting system utilizes
National Fuel Gas Code
the natural buoyancy of the heated flue
(ANSI Z223.1).
products to generate a negative draft. This
draft forces flue products to rise vertically
through a rooftop flue termination. The vent
connection is made directly to the top of the
unit and combustion air supplied from the
mechanical room. Properly sizing vent
material and the use of a barometric
damper (when required) will lead to proper
vent operation.
(FIG. 7) BAROMETRIC DAMPER INSTALLATION
8
L o c h i n v a r '
D E S I G N E R S G U I D E C O P P E R
The minimum flue pipe diameters for
Copper-Fin models, utilizing negative draft
venting are as follows:
(TABLE B)
FLUE SIZES AND COMBUSTION AIR PIPE SIZES
MODEL
NUMBER
CW 495
CW 645
CW 745
CW 986
CW 1256
CW 1436
CW 1796
CW 2066
Size vent material using the "FAN" category
of vent sizing tables in the latest edition of
the National Fuel Gas Code. "FAN" applies
to fan-assisted combustion appliances in
Category I.
Barometric Dampers
A barometric damper is required when draft
exceeds 0.08 inches of negative water
column. When installed and adjusted
properly, a barometric damper will maintain
draft between 0.02 and 0.08 inches of
negative water column ensuring proper
operation.
Multiple unit installations with combined
venting also require barometric dampers to
regulate draft at each unit. Again, the
negative draft must be within the range of
0.02 to 0.08 inches of negative water
column to ensure proper operation.
-
F I N W A T E R H E A T E R
FLUE SIZE
6"
8"
8"
10"
12"
12"
14"
14"
6 1 5 - 8 8 9 - 8 9 0 0