Carrier N92ESN Installation, Start-Up, Operating And Service And Maintenance Instructions page 18

N92ESN: Installation, Start-up, Operating and Service and Maintenance Instructions
FURNACE
CASING WIDTH
IN. (mm)
Upflow Applications on Combustible or Noncombustible Flooring
Downflow Applications on Noncombustible Flooring
21
(533) Downflow applications on combustible flooring
Downflow Applications on Combustible Flooring with coil assembly
Upflow Applications on Combustible or Noncombustible Flooring
Downflow Applications on Noncombustible Flooring
24-1/2
(622) Downflow applications on Combustible flooring
Downflow Applications on Combustible Flooring with coil assembly
*. Not all families have these models
A
PLENUM
OPENING
B D
FLOOR
OPENING
C
Fig. 25 – Installation on Combustible Flooring
Filter Arrangement
WARNING
!
FIRE, CARBON MONOXIDE AND POISONING
HAZARD
Failure to follow this warning could result in fire, personal injury or
death.
Never operate a furnace without a filter or filtration device installed.
Never operate a furnace with filter or filtration device access doors
removed.
There are no provisions for an internal filter in these furnaces. An
external filter rack is required and is purchased separately. A field
supplied accessory air cleaner may also be used in place of the filter
rack.
For upflow applications, the filter can be installed on either side of the
furnace, the bottom of the furnace or any combination of side and
bottom of the furnace. (See Fig.
For downflow applications, the filter rack (or field supplied accessory air
cleaner) must only be connected to the bottom opening on the furnace
(See Fig. 22).
For horizontal applications, the filter rack (or field supplied accessory air
cleaner) can be connected to the bottom opening on the furnace. For side
return use in the horizontal position, refer to
bottom openings are used in Fig. 23
filter.
A filter rack or any field supplied accessory air cleaner can also be
installed in the common return duct prior to entering the return air
opening in any orientation.
Refer to the instructions supplied with the Filter Rack or accessory air
filter for assembly and other details.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Table 5 – Opening Dimensions - In. (mm) (Continued)
APPLICATION
(Subbase not required)
(Subbase not required)
(Subbase required)
coil or coil box (Subbase not required)
(Subbase not required)
(Subbase not required)
(Subbase required)
coil or coil box (Subbase not required)
FURNACE
FURNACE
(OR COIL CASING
WHEN USED)
APPROVED
COIL ASSEMBLY
OR
COIL BOX
COMBUSTIBLE
COMBUSTIBLE
FLOORING
FLOORING
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
SHEET METAL
PLENUM
FLOOR
FLOOR
OPENING
OPENING
21)
Fig. 23. If both side and
each opening used will require a
PLENUM OPENING
A
19-1/2
(495)
19-3/8
(492)
18-5/8
(473)
19
(483)
23
(584)
22-7/8
(581)
22-1/8
(562)
22-1/2
(572)
Due to the relatively high pressure drops of 1-in (25 mm) thick
after-market filter media, it is recommended that the filtration system be
designed for at least 2-in (51 mm) thick media.
Filter and Return Duct Sizing
Pressure drop must be taken into account when sizing filters, filter racks,
IAQ devices, and associated system ductwork. See
comparison of Pressure Drop (initial/clean resistance to airflow) versus
Airflow for a variety of filter media types and sizes. These are
representative numbers. Consult the filter or IAQ device manufacturers'
specification sheet for performance data for a particular filter media or
A10491
IAQ device.
Design the filter and associated ductwork for the best match of pressure
drop versus filter size. Best practice usually chooses filter systems with
pressure drops under 0.2 in. W.C. (50 Pa), with the best blower electrical
efficiency and system airflow performance occurring with filter pressure
drops under 0.1 in. W.C. (25 Pa).
Design the duct system FIRST to determine how much pressure drop
may be allowed in the filter system. See the Air Ducts section.
Excessive filter pressure drop often compromises system airflow and
duct performance, causes inadequate airflow to the furthest ends of the
duct system, as well as causes excess noise and higher than anticipated
electrical consumption.
Provide duct transitions, as required, to smoothly transition airflow from
the return duct system to the filter (or IAQ device) to the furnace when
the dimensions of the ductwork or furnace return air opening do not
match the required filter or IAQ device dimensions. See the instructions
supplied with factory-accessory duct adapters.
18
FLOOR OPENING
B C
21-5/8 20-1/8
(549) (511)
19 20
(483) (508)
19 20-1/4
(483) (514)
19 20
(483) (508)
21-1/8 23-5/8
(537) (600)
19 23-1/2
(483) (597)
19 23-3/4
(483) (603)
19 23-1/2
(483) (597)
NOTICE
!
D
22-1/4
(565)
19-5/8
(498)
20-5/8
(600)
20
(508)
22-1/4
(565)
19-5/8
(498)
20-5/8
(600)
20
(508)
Table 6 for a