Table of Contents
Advertisement
FURNACE
CASING
WIDTH
Table 4_Opening
Dimensions - In. (mm)
APPLICATION
PLENUM OPENING
FLOOR OPENING
A
B
C
D
Upflow Applications on Combustible or Noncombustible
Flooring
12-11/16
21-5/8
13-5/16
22-1/4
(subbase not required)
(322)
(549)
(338)
(565)
Downflow Applications on Noncombustible
Flooring
12-9/16
19
13-3/16
19-5/8
14-3/16
(subbase not required)
(319)
(483)
(335)
(498)
(360)
Downflow Applications on Combustible Flooring
11-13/16
19
13-7/16
20-5/8
(subbase required)
(284)
(483)
(34t)
(600)
Downflow Applications on Combustible Flooring with Coil END4X,
12-5/16
19
13-5/16
20
ENW4X or Coil Casing NAEA (subbase not required)
(319)
(483)
(338)
(508)
Upflow Applications on Combustible or Noncombustible
Flooring
16
21-5/8
16-5/8
22-1/4
(subbase not required)
(406)
(549)
(422)
(565)
Downflow Applications on Noncombustible
Flooring
15-7/8
19
16-1/2
19-5/8
17-1/2
(subbase not required)
(403)
(483)
(419)
(498)
(445)
Downflow Applications on Combustible Flooring
15-1/8
19
16-3/4
20-5/8
(subbase required)
(384)
(483)
(425)
(600)
Downflow Applications on Combustible Flooring with Coil END4X,
15-1/2
19
16-1/2
20
ENW4X or Coil Casing NAEA (subbase not required)
(394)
(483)
(419)
(508)
U pflow Applications on Combustible or Noncombustible
Flooring
19-1/2
21-5/8
20-1/8
22-1/4
(subbase not required)
(495)
(549)
(511)
(565)
Downflow Applications on Noncombustible
Flooring
19-3/8
19
20
19-5/8
21
(subbase not required)
(492)
(483)
(508)
(498)
(533)
Downflow Applications on Combustible Flooring
18-5/8
19
20-1/4
20-5/8
(subbase required)
(473)
(483)
(514)
(600)
Downflow Applications on Combustible Flooring with Coil END4X,
19
19
20
20
ENW4X or Coil Casing NAEA (subbase not required)
(483)
(483)
(508)
(508)
U pflow Applications on Combustible or Noncombustible
Flooring
23
21 - 1/8
23-5/8
22-1/4
(subbase not required)
(584)
(537)
(600)
(565)
Downflow Applications on Noncombustible
Flooring
22- 7/8
19
23-1/2
19-5/8
24-1/2
(subbase not required)
(581)
(483)
(597)
(498)
(622)
Downflow Applications on Combustible flooring
22-1/8
19
23-3/4
20-5/8
(subbase required)
(562)
(483)
(603)
(600)
Downflow Applications on Combustible Flooring with Coil EN D4X,
22-1/2
19
23-1/2
20
ENW4X or Coil Casing NAEA (subbase not required)
(572)
(483)
(597)
(508)
AIR DUCTS
General Requirements
The duct system should be designed and sized according to
accepted national standards such as those published by: Air
Conditioning
Contractors
Association
(ACCA), Sheet Metal
and
Air
Conditioning
Contractors
National
Association
(SMACNA) or American Society of Heating, Refrigerating and
Air Conditioning
Engineers
(ASHRAE)
or consult The Air
Systems Design Guidelines reference tables available from
your local distributor.
The duct system
should be sized to
handle
the
required
system
design
CFM at the design
external
static
pressure.
The
furnace
airflow
rates
are
provided in Table 5 - AIR DELIVERY-CFM
(With Filter).
When a furnace is installed so that the supply ducts carry air
circulated
by the
furnace
to areas
outside
the
space
containing the furnace, the return air shall also be handled by
duct(s) sealed to the furnace casing and terminating
outside
the space containing the furnace.
Secure ductwork with proper fasteners for type of ductwork
used. Seal supply-
and return-duct
connections
to furnace
with code approved tape or duct sealer.
NOTE:
Flexible
connections
should
be used
between
ductwork and furnace to prevent transmission
of vibration.
Ductwork
passing
through
unconditioned
space should
be
insulated and sealed to enhance system performance. When
air conditioning is used, a vapor barrier is recommended.
Maintain
a
1-in.
(25 mm)
clearance
from
combustible
materials to supply air ductwork for a distance of 36 in. (914
mm) horizontally
from the furnace. See NFPA 90B or local
code for further requirements.
Ductwork Acoustical Treatment
NOTE:
Metal duct systems that do not have a 90 degree
elbow and 10 ft. (3 M) of main duct to the first branch take-off
may require
internal
acoustical
lining. As an alternative,
fibrous ductwork may be used if constructed
and installed in
accordance
with the latest edition of SMACNA construction
standard on fibrous glass ducts. Both acoustical
lining and
fibrous ductwork shall comply with NFPA 90B as tested by UL
Standard 181 for Class 1 Rigid air ducts.
Supply Air Connections
For a furnace not equipped with a cooling coil, the outlet duct
shall
be provided
with a removable
access
panel. This
opening shall be accessible when the furnace is installed and
shall be of such a size that the heat exchanger
can be
viewed
for possible
openings
using light assistance
or a
probe can be inserted for sampling the air stream. The cover
attachment shall prevent leaks.
441 01 1402 02
13
Hide quick links:
Advertisement
Table of Contents
