Air For Combustion Air De Combustion; Risque D'empoisonnement Par Monoxyde; General Généralités - Dettson RHB-105 Guide D'installation Et Manuel Du Propriétaire

2.5 AIR FOR COMBUSTION AIR DE
COMBUSTION
WARNING
POISONOUS CARBON MONOXIDE GAS HAZARD.
Comply with NFPA or CSA standards for the
installation of Oil
applicable provisions of local building codes
to provide combustion and ventilation air. Failure
to provide adequate combustion and ventilation
air can result in death or personal injury.
MISE EN GARDE

RISQUE D'EMPOISONNEMENT PAR MONOXYDE

DE CARBONE. Référer aux codes d'installation
des appareils au mazout ANSI/NFPA (aux États-
Unis) ou CSA (au Canada) et aux codes locaux
pour fournir l'air de combustion et de ventilation.
Une quantité insuffisante d'air de combustion peut
occasionner une flamme malpropre, des odeurs
dans la maison, le refoulement des appareils de
combustion et peut entraîner des nausées ou
l'asphyxie et/ou la mort des occupants.
2.5.1 General Généralités
Oil furnaces must have an adequate supply of
combustion air. It is common practice to assume that
older homes have sufficient infiltration to accommodate
the combustion air requirements for the furnace.
However, home improvements such as new windows,
doors, and weather stripping have drastically reduced the
volume of air infiltration into the home.
Home air exhausters are common.
kitchen fans, power vented clothes dryers and water
heaters all tend to create a negative pressure in the
home. Should this occur the chimney becomes less and
less effective and can easily downdraft.
Heat Recovery Ventilation Systems (HRVS) are gaining
in popularity. HRVS are not designed to supply
combustion air. If not properly balanced, a serious
negative pressure condition could develop in the
dwelling.
For buildings with tight construction, provide openings
directly to outside or to a ventilated crawl space or attic.
Size the openings to the same specifications as for the
furnace location per the following paragraphs. Follow
state, provincial or local codes when sizing adequate
combustion and ventilation air openings. In absence of
codes, use the following guidelines when furnace is in a
confined room (defined by NFPA 31 as less than 7200
cubic feet per 1 GPH input of all appliances in area. A
room 8 ft. high x 30.0 ft. x 30.0 ft. is 7200 cu. ft.).
Burning Equipment and
Bathroom and
Provide two permanent openings
Opening locations
One within 12 inches of ceiling, one within 12 inches
of floor. Minimum height or width dimension of each
rectangular opening should be at least 3 inches.
When inside air is used
Each opening must freely connect with areas having
adequate infiltration from outside. Each opening should
be at least 140 sq. in. per 1 GPH input (1 sq. in.
per 1000 BTU input) of all fuel-burning appliances plus
requirements for any equipment that can pull air from
room (including clothes dryer and fireplace).
When outside air is used
Connect each opening directly, by way of ducts to the
outdoors, or to crawl or attic space that freely connects
with outdoors. Size per below:
• Through outside wall or vertical ducts – at least 35 sq.
in. per 1 GPH input (1 sq. in. per 4000 BTU input)
of all fuel burning appliances plus requirements for any
equipment that can pull air from room (including clothes
dryer and fireplace).
• Through horizontal ducts – at least 70 sq. in. per 1 GPH
furnace input (1 sq. in. per 2000 BTU input) of all fuel-
burning appliances plus requirements for any equipment
that can pull air from room (including clothes dryer and
fireplace).
• Where ducts are used, they should have the same
cross-sectional area as free area of openings to which
they connect. Compensate for louver, grille or screen
blockage when calculating free air openings. Refer to the
manufacturers' instructions for details. If unknown, use:
a. Wood louvers, which provide 20-25% free air.
b. Metal louvers or grilles, which provide 60-75% free air.
Lock louvers in open position or interlock with equipment
to prove open before furnace operation.
Basement installations
When the furnace is located in an unconfined space,
such as an unpartitioned basement, adequate air should
normally be available without additional openings. An
unconfined space is defined as one having no less than
50 cubic feet room volume per 1,000 BTU/h input of all
appliances in the space.
If the house is of tight construction, provide air openings
to the basement directly from outside or from a ventilated
attic. Size the openings as described above under "When
outside air is used".
Closet installations – special NOTICE
Openings in closet doors
Provide TWO openings – one within 6 inches of top
of closet door, the other within 6 inches of the bottom
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