Category Iv - Vertical - Through The Roof Or Unused Chimney; Determine Termination Location; Fig. 15 - Category - Iv - Vertical Termination Of Vent Pipe - IDEAL Exalt Solo 110 Manual

CHAPTER 3 - CATEGORY IV (INDOOR AIR) INSTALLATION OF VENT/AIR PIPING
3.1. Category IV - Vertical - Through the Roof
or Unused Chimney
NOTICE
• 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/
• 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.
WARNING
A gas vent extending through a roof must not
terminate 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 can result in substantial property
damage, serious injury, or death.
NOTICE
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 an
®
AL 29-4C Stainless Steel or Polypropylene
vent system, there may be some variations.
Consult the appropriate vent manufacturer for
recommendations and clarifications.

Fig. 15 - Category - IV - Vertical Termination of Vent Pipe

24
CSA B149.1.
Vent Termination

3.1.1 Determine Termination Location

Locate the vent and combustion air termination using
the following guidelines:
1. The total length of the vent piping must not exceed
the limits given in Table 1 on page 4.
2. The combustion air piping must terminate at the
boiler with a 90º elbow.
3. The vent piping must terminate vertically with
a coupling to accept the bird screen and must
be located 12" [30.5 cm] (18" [45.7 cm] in Canada)
above the highest anticipated snow level as shown
in Fig. 15 on page 24 below.
4. The following should be considered when
determining the location of the vent termination:
a. Locate the vent termination where flue vapors
will not damage surrounding shrubs, plants, 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 or building surfaces.
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
windows, 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.
5. The vent termination must also maintain the
following clearances; as shown in Fig. 16 on page
25.
a. At least 3 feet [0.9 m] from adjacent walls
b. At least 3 feet [0.9 m] below roof overhangs
c. At least 7 feet [2.1 m] above any public walkways