Carrier 58MEB Installation, Start-Up, And Operating Instructions Manual page 20

DUCTS
TO
O UTDOORS
12 " MAX
(305mm)
1 SQ IN.
PER 2000 B
BTUH*
DUCT S
TO
OUTDOORS
1 SQ IN.
PER 2000
A
BTUH*
12 " MAX
(305mm)
CIRCULA TING AIR DUCT S
*Minimum dimensions of 3 in. (76 mm).
NOTE: Use any of the following combinations of openings:
A & B C & D D & E F & G
Fig. 18 - - Air for Combustion, Ventilation, and Dilution
for Outdoors
WARNING
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in death and/or
personal injury.
Many homes require air to be supplied from outdoors for
furnace combustion, ventilation, and dilution of flue gases.
The furnace combustion air supply must be provided in
accordance with this instruction manual.
The Standard Method:
1. The space has no less volume than 50 ft
Btuh of the maximum input ratings for all gas appliances
installed in the space and
2. The air infiltration rate is not known to be less than 0.40
air changes per hour (ACH).
The Known Air Infiltration Rate Method shall be used, if the
infiltration rate is known to be:
1. Less than 0.40 ACH and
2. Equal to or greater than 0.10 ACH
Infiltration rates greater than 0.60 ACH shall not be used. The
minimum required volume of the space varies with the number of
ACH and shall be determined per Table 2 or Equations 1 and 2.
Determine the minimum required volume for each appliance in
the space and add the volumes together to get the total minimum
required volume for the space.
Table 2-Minimum Space Volumes were determined by using the
following equations from the National Fuel Gas Code ANSI
Z223.1-2006/NFPA54-2006, 9.3.2.2:
1. For other than fan-assisted appliances, such as a draft
hood-equipped water heater:
1 SQ IN.
PER 4000
BTUH*
12 "
D
(305mm)
MAX
VENT
THR OUGH
F
R OOF
1 SQ IN .
PER
4000
BTUH*
1 SQ IN .
PER
4000
BTUH*
E
G
12 "
(305mm)
MAX
C
12 " MAX
(305mm)
DUCT
1 SQ IN.
TO
PER 4000
OUTDOORS
BTUH*
A03174
3 3)
(1.4M per 1,000
CIRCULATING AIR
DUCTS
INTERIOR
HEATED
SPACE
CIRCULATING AIR DUCTS
* Minimum opening size is 100 sq in. with minimum dimensions of 3 in. (76
mm)
† Minimum of 3 in. (76 mm) when type-B1 vent is used.
Fig. 19 - - Air for Combustion, Ventilation, and Dilution
2. For fan-assisted appliances such as this furnace:
If:
= combined input of all other than fan-assisted appliances
I
other
in Btu/hr
= combined input of all fan-assisted appliances in Btu/hr
I
fan
ACH = air changes per hour (ACH shall not exceed 0.60.)
The following requirements apply to the Standard Method and to
the Known Air Infiltration Rate Method.
1. Adjoining rooms can be considered part of a space if:
a. There are no closeable doors between rooms.
b. Combining spaces on same floor level. Each opening
shall have free area of at least 1 in.
2
(2,000 mm /kW) of the total input rating of all gas
appliances in the space, but not less than 100 in.
2
(0.06 m ). One opening shall commence within 12 in.
(300 mm) of the ceiling and the second opening shall
commence within 12 in. (300 mm) of the floor. The
minimum dimension of air openings shall be at least
3 in. (80 mm). (See Fig. 19.)
c. Combining space on different floor levels. The
volumes of spaces on different floor levels shall be
considered as communicating spaces if connected by
one or more permanent openings in doors or floors
having free area of at least 2 in.
2
(4,400 mm /kW) of total input rating of all
gas appliances.
- - 20 - -
VENT THROUGH ROOF
12" MAX (305mm)
1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL
UNCONFINED
SPACE
6" MIN (152mm)
(FRONT)
Ü
1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL
12" MA X
(305mm)
from Indoors
2
/1,000 Btuh
2
/1,000 Btuh
A03175
A04002
A04003
2