Table of Contents
Advertisement
Figure 7. Equipment in Confined Space - All Air from
(All Air Through Ventilated Attic)
Figure 8. Equipment in Confined Space - All Air from
If this unit is being installed in an application with
combustion air coming in from a space serviced by an
exhaust fan, power exhaust fan, or other device which
may create a negative pressure in the space, take care
when sizing the inlet air opening. The inlet air opening
must be sized to accommodate the maximum volume
of exhaust air as well as the maximum volume of
combustion air required for all gas appliances serviced
by this space.
508405-01
Outside
Outside
WARNING
Roof Terminated
Exhaust Pipe
* See Maximum Vent Lengths table
NOTE-The inlet and outlet air openings shall each have a
free area of at least one square inch per 4,000 Btu (645mm
per 1.17kW) per hour of the total input rating of all equipment
in the enclosure.
Figure 9. Equipment in Confined Space
(Inlet Air from Ventilated Attic and Outlet Air to
Roof Terminated
Exhaust Pipe
Ventilation
Louvers
(Crawl Space)
Coupling or
3 in. to 2 in.
Transition
(Field Provided)
* See Maximum Vent Lengths table
NOTE-The inlet and outlet air openings shall each have a
free area of at least one square inch per 4,000 Btu (645mm
per 1.17kW) per hour of the total input rating of all equipment
in the enclosure.
Figure 10. Equipment in Confined Space
(Inlet Air from Ventilated Crawl Space and Outlet Air
Issue 2341
Ventilation Louvers
*Intake Debris
Screen
(Provided)
Furnace
Outside)
Inlet Air
Minimum
12 in. (305mm)
Furnace
above Crawl
Space Floor
*Intake Debris Screen Provided
to Outside)
Inlet Air
(Minimum 12 in.
(305mm) above
Attic Floor)
2
2
Page 9 of 53
Advertisement
Table of Contents
