Air Directly Through An Exterior Wall - Heat Controller 80+ AFUE Installation Instructions Manual

Ventilation louvers
at each end of attic
Vent or
Chimney
Attic
Insulation
Water
Heater
Furnace
Crawl Space
Figure 3. Combustion Air Drawn from a Crawl
Space or Vented Attic
Vent or
Attic
Chimney
Insulation
Water
Furnace
Heater
Total Input Rating Minimum Free Area
(Btuh) (Each Opening)
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Figure 4. Combustion Air Drawn from Outside
Through Vertical Ducts
8
Outlet air duct must be
at least 1 sq. in. per
4,000 Btuh of total
input rating. Must
extend above attic
insulation
Inlet air duct must be at
least 1 sq. in. per 4,000
Btuh of total input rating.
Ventilated Louvers for
unheated crawl space
Ventilation Louvers at
each end of attic
Outlet Air Duct must
be at least 1 sq. in.
per 4,000 Btuh of
total input rating.
Inlet and Outlet
Ducts must
extend above
attic insulation.
Inlet Air Duct must
be at least 1 sq. in.
per 4,000 Btuh of
total input rating.
12" Max
Round Duct
Diameter
100 in 12 inches
2
100 in 12 inches
2
100 in 12 inches
2
100 in 12 inches
2
120 in 13 inches
2
140 in 14 inches
2
160 in 15 inches
2
Vent or
Chimney
12" Max
- - -
- - -
- - -
See
Note
- - -
- - -
- - -
12" Max
Water Heater
Total Input Rating Minimum Free Area
(Btuh) (Each Opening)
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Figure 5. Combustion Air Drawn from Outside
Through Horizontal Ducts

Air Directly Through An Exterior Wall

If combustion air is provided directly through an exterior
wall, the two openings must each have free area of at least
1in per 4,000 Btuh of total appliance input. See Figure 6.
2
Vent or
Chimney
12" Max
- - -
- - -
- - -
Furnace
See
Note
- - -
- - -
- - -
Water Heater
12" Max
Total Input Rating Minimum Free Area
(Btuh) (Each Opening)
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Figure 6. Combustion Air Drawn from Outside
Through an Exterior Wall
NOTE: Each
- - -
- - -
Air Duct
- - -
opening to
Furnace
outside must
be at least 1
sq. in. per 2,000
Btuh of total
- - -
input rating.
- - -
Air Duct
- - -
Round Duct
Diameter
10 in 2 5 inches
15 sin 2 6 inches
20 in 2 7 inches
25 in 2 8 inches
30 in 2 9 inches
35 in 10 inches
2
40 in 10 inches
2
NOTE: Each opening
to outside must be at
least 1 sq. in. per
4,000 Btuh of total
input rating.
Round Duct
Diameter
10 in 4 inches
2
15 in 5 inches
2
20 in 5 inches
2
25 in 6 inches
2
30 in 6 inches
2
35 in 7 inches
2
40 in 8 inches
2