12
3.3.2
– Sidewall Configuration Guidelines
Sidewall Vent Terminations:
o
Sidewall vents can terminate horizontally, but in areas
with heavy rain a downturned 45
°
elbow can be installed
to keep water from blowing into the opening. Rain
entering the venting will drain out through the condensate
removal system, but may waste neutralizer media, so it
should be avoided where possible.
o
In penetrating through a windward wall, a horizontally
mounted tee (i.e. with all openings on the same plane)
can be installed to reduce the effect of wind loading.
o
Position terminations so they are not likely to be damaged
by foreign objects, or exposed to a build-up of snow, ice
debris, etc., which can cause a blocked flue condition.
o
Do not terminate the vent in a window well, stairwell,
alcove, courtyard or other recessed area. The vent cannot
terminate below grade.
o
Position the vent termination where vapours will not
damage walls or plants or may otherwise be
objectionable.
o
The vent outlet MUST NOT terminate below a forced air
inlet at any distance.
o
NOTE:
If the hydronic system design uses high water
temperatures, uncondensed water vapour in the flue
products will find its way into the vent, and could form
large plumes of steam at the vent termination. This is not
harmful to the water heater but can be unsightly and
obstruct views from windows. The steam can also cause
discoloration on exterior building surfaces. Adjacent brick
or masonry surfaces should be protected with a rust
resistant sheet metal plate.
Sidewall Combustion Air Inlets:
o
Sidewall combustion air inlets consist of a single 90°
elbow, installed on the end of the horizontal pipe
penetrating the wall. A bird screen should be installed on
the open end of the elbow.
o
Combustion air supplied from outdoors must be free of
contaminants.
o
Incorrect installation and/or location of the air inlet cap can
allow flue products to be drawn back into the appliance.
This can result in incomplete combustion and potentially
hazardous levels of carbon monoxide in the flue products.
This will cause operational problems with the appliance
and if left uncorrected, will lead to conditions that can
cause personal injury or death.
Clearances:
o
The vent terminal shall terminate at least 3 ft. (1M) above
any forced air inlet within 10 ft. (3M) horizontally.
o
The vent shall not terminate less than 7 ft. above a public
walkway due to the normal formation of water vapour in
the combustion process.
o
The vent system shall terminate at least 3 foot (1M) above
grade, or above projected snow levels.
o
The vent terminal shall not be installed closer than 3 feet
(1 m) from an inside corner of an L-shaped structure,
window well, stairwell, alcove, courtyard or other
recessed area as wind eddies could affect water heater
performance or cause recirculation.
o
DO NOT terminate closer than 4 feet (1.25m) horizontally
and vertically from any electric meter, gas meter,
regulator, relief valve, or other equipment. In all cases
local codes take precedence
o
Position the vent termination where vapours will not
damage walls or plants or may otherwise be
objectionable.
o
The vent outlet MUST NOT terminate below a forced air
inlet at any distance.
o
The combustion air opening shall
be at least 12” inches
(30cm) above grade, or above projected snow levels.
o
The combustion air opening should be 12” from the wall,
to remove it from the surface pressure zone.
o
The point of termination for the sidewall combustion air
inlet terminal MUST be located a minimum of 3 feet (1M)
horizontally or 12 inches (0.30M) below the point of flue
gas termination (vent cap) if it is located within a 10 foot
(3M) radius of the flue outlet.
Sidewall Vent and Air Intake - Vertical Arrangement
Sidewall Vent and Air Intake - Horizontal Arrangement