Air From Inside; Outdoor Air Using Vertical Ducts - Nordyne TA-060C-08A Installation Instructions Manual

See the venting section for venting guidelines
and specifications.
Air From Inside (See Figure 9)
If combustion air is taken from the heated
space, the two openings must each have a free
area of at least one square inch per 1,000 Btuh
of total input of all appliances in the confined
space, but not less than 100 square inches
of free area. For example, if the combined input
rate of all appliances is less than or equal to
100,000 Btuh, each opening must have a free
area of at least 100 square inches. If the com-
Vent or
Chimney
Furnace
Water Heater
Minimum
Total Input Free Area
Rating (Btu/hr) (Each Opening)
100 sq. in.
40,000
100 sq. in.
60,000
100 sq. in.
80,000
100 sq. in.
100,000
120 sq. in.
120,000
140 sq. in.
140,000
160 sq. in.
160,000
Figure 9. Equipment in a Confined
Space with all Combustion
Air Drawn from the Inside
Vent or
Chimney
Attic
Insulation
Furnace
Water Heater
a. All Combustion Air from Ventilated Attic.
Minimum
Total Input Free Area
Rating (Btu/hr) (Each Opening)
40,000 10 sq. in.
60,000 15 sq. in.
80,000 20 sq. in.
100,000 25 sq. in.
120,000 30 sq. in.
140,000 35 sq. in.
160,000 40 sq. in.
Figure 10. Equipment in a Confined
Space with all Combustion Air Drawn
from the Outside through Vertical Ducts
14
bined input rate of all appliances is 120,000
Btuh, each opening must have a free area of at
least 120 square inches.

Outdoor Air Using Vertical Ducts

(See Figure 10)
If combustion air is taken from outdoors through
vertical ducts, the openings and ducts must
have a minimum free area of one square inch
per 4,000 Btuh of total appliance input. In instal-
lations drawing combustion air from a ventilated
attic, both air ducts must extend above the attic
insulation.
If the unit is installed in an area with an exhaust
Openings to
fan, provide sufficient ventilation to prevent
adjacent space.
Each opening must
negative pressures from occurring in the room.
be at least 100 sq. in.
or 1 sq. in. per 1000
Btuh of total input
rating, whichever is
greater. See minimum
The combustion air openings must not be re-
area per table.
stricted in any manner.
12" Max.
12" Max.
Round Duct
Diameter
12"
12"
12"
12"
13"
14"
15"
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
4"
5"
5"
6"
6"
7"
8"
! CAUTION:
Do not supply combustion air from an
attic space that is equipped with power
ventilation or any other device that may
produce a negative pressure.
12" Max
- - -
- - -
- - -
- - -
- - -
- - -
Water Heater
12" Max
Total Input
Rating (Btuh) (Each Opening)
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Figure 11. Equipment in a Confined
Space with all Combustion Air Drawn
from the Outside through Exterior Wall
Vent or
Chimney
Furnace
Minimum
Free Area Round Duct
Diameter
10 sq. in. 4"
15 sq. in. 5"
20 sq. in. 5"
25 sq. in. 6"
30 sq. in. 6"
35 sq. in. 7"
40 sq. in. 8"