Carrier 58BB - Manual (Page 4)

DUCTWORK RECOMMENDATIONS
1. Install locking-type dampers in all branch or
individual ducts to balance out system.
2. Use tapered fittings or starter collars between
ducts and plenum.
3. Use flexible duct connection (asbestos cloth)
between furnace and discharge plenum.
4. Install acoustical insulation in warm air plenum;
install sound traps in short run ducts.
5. Run return air connections under floor or I'un
full size return from space outside enclosed
area. If outdoor air is used, combination of
outdoor and return air requires duct design and
diverting dampers so installed that volume of
circulating air entering furnace cannot be re­
duced or restricted below that which would
normally enter thru circulating air intake of
furnace
FILTERS — Filters are shipped from factory in
blower compartment of furnace. (See Fig. 3.) To
gain access, remove top front panel and filter
compartment doors located at right- and left-hand
sides of vent. Install by raising filters above right-
and left-hand side of blower and positioning on
filter rack as shown in Fig. 3. As an aid in filter
removal, an access panel could be field fabricated
in the front of the return air supply plenum.
VENTS — Vent furnace to permanent chimney or
thru roof with vent of approved design. (Type B
vent is recommended.) Observe local ordinances.
1. Size flue pipe connections same as furnace
vent connection. (See Fig. 1 and Table 1.)
2. Run pipe as directly as possible with minimum
number of turns.
3. Maintain minimum pitch of 1/4 in. per linear
ft on horizontal runs. Pitch should not exceed
75% of vertical vent.
4. Maintain minimum angle of 60 degrees from
vertical for vent pipe crossovers in attic.
5. Rigidly support pipe with hangers or straps.
6. Do not connect into a chimney serving an
open fireplace.
7. If chimney is used, total equivalent straight
length of flue piping between furnace and flue
pipe connection at chimney must not be
greater than 75% of vertical height of chimney
above flue pipe connection.
8. Install flue pipe to extend thru chimney wall
but not beyond inside wall of flue.
9. Minimum vertical stack height is 5 ft. Extend
flue pipe at least 3 ft above roof and 2 ft above
any object within a 15-ft radius. Ensure that
Table 4 — Pipe Sizing*, Capacity For Natural Gas,
Cu Ft/Hr
PIPE LENGTH (ft)t
10 20 30 40 50 60 70 80
132 92 73 63 56 50 46 43
278 190 152 130 115 105 96 90
520 350 285 245 215 195 180 170
1050 730 590 500 440 400 370 350
X — J ___ _-,J
PIPE SIZE
’4
1
U/4
*Based on pressure drop of 0 3 in. wg, 0 6 sp gr gas
fWithout elbows
NOTE: For pipe sizing capacity for LP gases, refer to NFPA No. 54
vent outlet terminates in an approved cap with
a venting capacity not less than that of the
vent. (See Table 1 for vent sizes.)
10. Insulate flue pipe where it passes near com­
bustible material. Underwriter’s Laboratories
(UL) require that uninsulated flue pipe be
installed with a minimum clearance of 6 in.
from combustible materials. Vent piping,
which meets with National Board of Fire
Underwriter’s Specifications for type B vents,
may be installed with a clearance of 1 in. from
combustible materials.
If other gas appliances are vented into
common flue, flue area must equal largest vent area
plus one-half total areas of other vent conneetors.
GAS PIPING — Install piping per national and local
codes, and NFPA No. 54.
1. Furnish gas line from main gas supply to
furnace.
2. Size supply pipe per volume of gas used and
allowable pressure drop. (See Table 4.) Supply
pipe size must at least equal that of furnace gas
connection.
■ 3. Refer to NFPA No. 54 for additional suggested
methods of piping.
a. Install drop pipe adjacent to, but not in
front of furnace.
b. Install manual shutoff valve on gas piping
per local codes.
c. Install tee in pipe at same elevation as gas
inlet connection to unit; provide ground
joint union between tee and furnace
controls.
d. Extend drip leg and cap it.
e. Test for pressure and leaks.
CAUTION: Never rise open flame for testjxig.