Indoor Combustion Air In Confined Or Unconfined Space - Westinghouse WGR-076 Series Installation, Start-Up, Maintenance, Parts, Warranty

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Contractors must check state and local codes before installing
through an existing vent opening. State and local codes always
take precedence over manufacturer's instructions. Failure to
check state and local codes before installing through an existing
opening could result in property damage and add significantly
to installation costs.
If an existing venting system is converted for use with this
heater, the installer must ensure that the existing venting
system is clean and free from particulate contamination
that could damage the heater. Failure to do so could result
in property damage and heater failure. Such failure IS NOT
covered under warranty.
Concentric Venting Through an Existing System
NOTE: The following instructions refer only to venting through
an existing vent system, and not to venting with Westinghouse's
optional concentric vent kits. Refer to Concentric Vent Kit
installation manual (LP-166) for further information on venting
Concentric Venting Through an Existing System
1
Figure 12 - 1, 2 - Concentric Venting Through an Existing System, 3, Chase Venting Through an Existing System
NOTE: These drawings are meant to demonstrate system venting only. The installer is responsible for all equipment and detailing required by
local codes.
with the optional concentric vent kits.
Concentric venting through an existing system must run
vertically through the roof. See Table 9 for proper minimum
vent sizing. Use only the approved venting materials specified
in Table 5 for piping the system. All instructions listed in this
Venting section apply. See Figures 12-1 and 12-2 for venting
demonstrations.
The upper and lower vent terminations as well as all joints in
the venting system must be properly sealed to ensure that all
combustion air is drawn properly and exhaust does not leak
from the system. Failure to properly seal the venting system
will result in property damage, serious personal injury, or death.
Chase Venting Through an Existing System
When venting as a chase, follow all instructions included in this
Venting section, including those in the previous Concentric
Venting Through an Existing System section. See Figure 12-3 for
chase venting demonstration.
WHL-001 Rev. 3.16.15
Concentric Venting Through an Existing System
2
AIR INTAKE
W/ SCREEN

3. Indoor Combustion Air in Confined or Unconfined Space

This heater requires fresh, uncontaminated air for safe
operation and must be installed in a mechanical room where
there is adequate combustion and ventilating air. NOTE: To
prevent combustion air contamination, see Table 2.
Combustion air from the indoor space can be used if the space
has adequate area or when air is provided through a duct or
louver to supply sufficient combustion air based on the water
heater input. Never obstruct the supply of combustion
air to the water heater. If the water heater is installed in
areas where indoor air is contaminated (see Figure 12) it is
imperative that the water heater be installed as direct vent so
that all combustion air is taken directly from the outdoors into
the water heater intake connection.
Unconfined space is space with volume greater than 50 cubic
feet per 1,000 Btu/hour (4.8 cubic meters per kW) of the
total input rating of all fuel-burning appliances installed in
that space. Rooms connected directly to this space, through
Chase Venting Through an Existing System
3
EXISTING
VENT
AIR INTAKE
W/ SCREEN
openings not furnished with doors, are considered part of the
space.
Confined space is space with volume less than 50 cubic feet
per 1,000 Btu/hour (4.8 cubic meters per kW) of the total input
rating of all fuel-burning appliances installed in that space.
Rooms connected directly to this space, through openings not
furnished with doors, are considered part of the space.
When drawing combustion air from inside a conventionally
constructed building to a confined space, such space should
be provided with two permanent openings: one located 6"
(15 cm) below the space ceiling, the other 6" (15cm) above
the space floor. Each opening should have a free area of one
square inch per 1,000 Btu/hr (22cm2/kW) of the total input of
all appliances in the space, but not less than 100 square inches
(645cm2).
If the confined space is within a building of tight construction,
air for combustion must be obtained from the outdoors as
outlined in the Venting section of this manual. See Figure 13.
INTAKE