Carrier 58TUA - Manual (Page 9)

A WARNING
When this furnace is converted to Category III it must have its
own dedicated vent. DO NOT common vent with any other
appliance. Common venting with other appliances will result
in spillage of flue gas and failure of vent system which may
cause property damage, personal injury, or death.
A gastight heat dissipator, condensate drain tube and clamps,
condensate trap and mounting bracket, and draft safeguard modi­
fication plate
are provided in the kit. No substitution for any of the components
may be made when installing furnace with a Category III vent
system.
A WARNING
Table 6 lists the required vent size for furnace sizes based on
high-fire input. Refer to the furnace rating plate and Table 6
to determine size of Special Gas Vent pipe. An incorrectly
sized vent may cause inadequate wind resistance, poor
operation, or vent failure. Vent failure may result in property
damage, or flue gas spillage, resulting in personal injury or
death.
Table 6—Vent Pipe Size*
HIGH-FIRE INPUT
(BTUH)NORMAL POSITION
PIPE DIAMETER
40,000—84,000 3 in.
85,000—140,000 4 in.
*Only Category III conversion kit specified on furnace and pipe size listed for
furnace input shall be used.
All joints in the vent system, between vent system and heat
dissipator, and between heat dissipator and furnace must be sealed
airtight with only the high temperature RTV specified by the
special gas vent pipe manufacturer. The accessory kit contains
provisions for vent condensate drainage. Drain and trap must be
installed pet kit instructions. Incorrect drain installations may
cause furnace component failure. Furnace installations in uncon­
ditioned spaces where temperature may fall below 32°F REQUIRE
freeze protection (heat tape) on condensate trap.
HIGH TEMPERATURE PLASTIC, SPECIAL GAS VENT IN­
STALLATION
Cutting
1. Hand cut piping with a sharp saw. Saw blade must have at
least 24 teeth pet in.
2. Cut pipe squarely. Use of a miter box when cutting pipe is
recommended.
NOTE: DO NOT cut with power saw. Doing this may cause
immediate or eventual cracking or shattering of pipe. DO NOT cut
or alter fittings.
Adhesive Joining
Pipe and fittings are joined together using high temperature RTV
adhesive/sealants. Use ONLY adhesives listed by vent manufac­
turer. Do not use any other adhesives or sealants. Do not use
solvent cements.
Do not drill holes in pipe or fittings. Do not use sheet metal or
other types of screws to join plastic piping or fittings. Do not use
rivets to join piping or fittings.
Before applying sealant, pipe ends must be smooth and clean.
1. Apply minimum 1/4-in. bead of adhesive/sealant entirely
around pipe end no more than 1/8-in. from end.
2. Push pipe and fitting together while twisting pipe into fitting.
3. Inspect joint for complete seal. Full curing of joints takes 24
hr.
A WARNING
Failure to ensure complete seal of all joints between furnace,
heat dissipator, vent pipes, and fittings will allow spillage of
flue gas, which may result in personal injury or death.
Inspect each joint after the adhesive/sealant has cured to ensure
that all joints are sealed. Reapply adhesive/sealant to any joints
that are suspected of flue gas leakage.
Vent Installation
Minimum vent length is 5 ft of straight pipe, one 90° long-radius
(sweep) elbow or equivalent, condensate drain assembly, and
termination (coupling and bird screen).
Maximum vent length is 40 ft of straight pipe, four 90° long-radius
(sweep) elbows, condensate drain assembly, and termination
(coupling and bird screen).
Length and number of elbows may be adjusted according to
equivalent ft of pipe for fittings shown in Table 7.
Example: If adding an additional 90° long-radius (sweep)
elbow, in a 3-in. diameter vent system, maximum vent length
must be reduced to 35 ft.
A coupling and bird screen are the recommended vent termination
for both horizontal and vertical vents. If a tee and 2 bird screens are
required for vertical vents, the allowable vent length must be
adjusted according to Table 7. No elbows shall be used as
terminations.
Table 7—Equivalent Pressure Drop in Length of
Straight Pipe for Fittings
FITTING
EQUIVALENT FT OF PIPE
3-In. Diameter 4-In. Diameter
90° Elbow 10 N/A
90° Sweep Elbow (Long-
Radius)
5 6
45° Elbow 5 5-1/2
Tee Used as an Elbow 10 10
Tee Used as a Termination 5 5
N/A—Not applicable
All horizontal mns of piping must slope backward towards drain
tee 1/4 in. per ft. The horizontal run between the drain tee and the
furnace must also slope towards the drain tee. Vent system must be
supported at least every 5 ft and at every elbow on horizontal mns.
Vertical mns must be supported at least every 10 ft by supports
listed by vent pipe manufacturer. Frame opening in floor using
lumber which is dimensionally consistent with stmctural members.
Framing must be level and must provide required air space
clearance to pipe.
Vertical Vent Termination
Where vent passes through roof, a listed flashing and storm collar
must be used to maintain required clearances and to keep weather
out. Framed opening must be large enough to maintain required air
clearance taking into account slope of roof. Install flashing and
storm collar as directed by vent manufacturer. Vertical termination
must be at least 2 ft horizontally from roof surface, at least 8 ft
away from any vertical wall, and must extend above roof as
required in kit instmctions. Vents extending 2-1/2 ft or more above
roof must be securely guyed or braced according to vent manu­
facturer’s Installation Instructions. Terminate with a coupling and
a bird screen.