Installation Manual

10
these pipes DO NOT reuse this venting system! This
recall does not apply to other plastic vent pipes, such
as white PVC or CPVC. Check for details on the CPSC
website or call their toll-free number [phone].
Ventilaire III or IV Air Quality Package
The Ventilaire air quality accessory packages are available
to meet the ventilation requirements as outlined in H.U.D.
Standard Part 3280.103 (b) (2). These packages introduce
outdoor air into the living space during furnace blower
operation. The VentilAire IV also serves to exhaust moist
and/or hot air from the attic space. See Figure 5 for typical
installation. Complete installation instructions are supplied
with each air quality package.
VentilAire III
VentilAire IV
Figure 5. VentilAire III & IV
Vent Freezing Protection
CAUTION:
When the vent pipe is exposed to temperatures
below freezing (i.e., when it passes through
unheated spaces, chimneys, etc.) the pipe
must be insulated with 1/2 inch thick sponge
rubber insulation, Armaflex-type insulation or
equivalent. Insulating pipe is important to avoid
condensate icing.
• Table 3 lists the maximum length of flue pipe that can
travel through an unconditioned space or an exterior
space. The total vent length must not exceed the
lengths noted in the table. For Canadian installations,
please refer to the Canadian Installation Code (CAN/
CGA-B149.1 or 2) and/or local codes.
• For extremely cold climates or for conditions of short
furnace cycles (i.e. set back thermostat conditions)
the last 18 inches of vent pipe can be reduced. It is
acceptable to reduce from 3” to 2-1/2” or, 3” to 2” if the
total vent length is at least 15 feet in length, and the
vent length is within the parameters specified in Table
2, (page 8). The restriction should be counted as 3
equivalent feet. Smaller vent pipes are less susceptible
to freezing, but must not be excessively restrictive.
• To prevent debris or creatures from entering the
combustion system, a protective screen may be installed
over the combustion air intake opening. The screens
hole size must be large enough to prevent air restriction.
WINTER
DESIGN
TEMPERATURE
MAXIMUM FLUE PIPE
LENGTH (FEET) IN
UNCONDITIONED & EXTERIOR SPACES
WITHOUT
INSULATION
WITH
INSULATION*
20 45 70
0 20 70
-20 10 60
*NOTE: Insulation thickness greater than 3/8 inch, based on an
R value of 3.5 (ft x F x hr) / (BTU x in.)
Table 3. Vent Protection
Existing Installations
When an existing furnace is removed from a vent system
serving other appliances, the existing vent system may
not be sized properly to vent the remaining appliances
(example: water heater). An improperly sized venting
system can result in the formation of condensate, leakage,
or spillage. The existing vent system should be checked
to make sure it is in compliance with NFGC and must be
brought into compliance before installing the furnace.
NOTE: If replacing an existing furnace, it is possible you
will encounter an existing plastic venting system that is
subject to a Consumer Product Safety Commission recall.
The pipes involved in the recall are High Temperature
Plastic Vent (HTPV). If your venting system contains
CIRCULATING AIR REQUIREMENTS
WARNING:
Do not allow combustion products to enter the
circulating air supply. Failure to prevent the
circulation of combustion products into the
living space can create potentially hazardous
conditions including carbon monoxide poisoning
that could result in personal injury or death.
All supply ducts must be secured to the furnace
with sheet metal screws and adequately sealed.
When supply air is provided through the bottom
of the unit, the joint between the furnace and the
plenum must be air tight.
The surface that the furnace is mounted on must
provide sound physical support of the furnace
with no gaps, cracks or sagging between the
furnace and the floor or platform.
Supply air ducts must not be connected to any
other heat producing device such as a fireplace
insert, stove, etc. This may result in fire, explosion,
carbon monoxide poisoning, personal injury, or
property damage.