ACV Prestige CPVC, User Manual

Page: 14 / 44

Direct Vent Installation of Vent/Air Piping
11
SECTION II - DIRECT VENT INSTALLATION
OF VENT/AIR PIPING
A Direct Vent appliance utilizes uncontaminated outdoor
air (piped directly to the appliance) for combustion.
Direct Vent - Vertical - Through the Roof or Unused
Chimney
The installation must conform to the requirements of
the authority having jurisdiction or, in the absence
of such requirements, to the National Fuel Gas
Code, ANSI Z223.1/ NFPA 54, and/or Natural Gas and
Propane Installation Code, CAN/CSA B149.1.
When using an inoperative chimney as a means of a
chase for the vent, the surrounding space within the
chimney cannot be used to draw combustion air or
vent another appliance.
A gas vent extending through a roof should not ter-
minate near an adjacent wall or below any building
extensions such as roof eaves, balconies or decks.
Failure to comply with the required clearances in
this manual could result in severe personal injury,
death or substantial property damage.
The information and diagrams outlining the fittings
and method of terminating the vent/combustion air
are directly related to PVC/CPVC vent systems.
When utilizing and AL29-4C® or Polypropylene vent
system there may be some variations. Consult the
appropriate vent manufacturer for recommenda-
tions and clarifications.
Determine Termination Location
Locate the vent and combustion air termination using the
following guidelines:
1. The total length of the vent or combustion air piping
must not exceed the limits given in Table 8 on page 8.
NOTICE
NOTICE
WARNING
NOTICE
Do not include the two 90 º elbows or tee used to ter-
minate the combustion air inlet exterior of the build-
ing when determining the total length of pipe.
2. The combustion air piping must terminate in an
upside down “U” shape fashion using two 90 º
elbows as shown in Fig. 1 page 12 or with a tee as
shown in Fig. 2 page 12. The termination must be
installed 12” [30.5 cm] (18” [45.7 cm] Canada) above
the highest anticipated snow level.
3. The vent must terminate vertically with a coupling to
accept the bird screen and must be located 12” to 24”
[30.5 cm to 61 cm] above the combustion air inlet as
shown in Fig. 1 & Fig. 2 on page 12.
4. The vent and combustion air terminations must be
located a radial distance of 12” to 24” [30.5 cm to 61
cm] from centerline of vent termination to centerline
of air termination as shown in Figs. 1 & 2 on page
12.
5. The following should be considered when deter-
mining the location of the vent and combustion air
terminations:
a. Locate the vent termination where flue vapors
will not damage surrounding shrubs, plants or
air conditioning equipment or be objectionable
to the homeowner.
b. The flue products will form a noticeable plume of
water vapor as they condense in colder air.
Avoid terminating the vent in areas where the
plume could obstruct window views.
c. Prevailing winds could cause freezing of flue
gas condensation and a buildup of water / ice on
surrounding plants, building surfaces or com-
bustion air inlet.
d. Avoid locations where prevailing winds could
affect the performance of the boiler or cause
recirculation of the flue gases, such as inside
corners of buildings, near adjacent buildings,
vertical surfaces, window wells, stairwells,
alcoves, courtyards, or other recessed areas.
e. Do not terminate the vent above doors or win-
dows: flue condensate could freeze causing ice
formations.
f. Locate the vent termination to prevent possible
condensate damage to exterior finishes.
g. Avoid locations of possible accidental contact of
flue vapors with people or pets.
NOTICE