Weil-McLain CG-4 - COMBUSTION AIR AND VENTILATION OPENINGS; CHIMNEY OR VENT REQUIREMENTS

Section I: Pre-Installation
CODES
Installation must comply with all local codes, laws, regula¬
tions and ordinances, also National Fuel Gas Code ANSI
Z223.1-latest edition. When required, installation must con¬
form to Standard for Controls and Safety Devices for Auto¬
matically Fired Boilers, ANSI/ASME CSD-1. Safe lighting
and other performance criteria were met with the gas mani¬
fold and control assembly provided on boiler when boiler
underwent tests specified in ANSI Z21.13-latest edition.
Canadian installations must comply with CAN/CGA B149.1
or .2 Installation Codes.
COMBUSTION AIR AND VENTILATION OPENINGS
Combustion air and ventilation openings must comply with
Section 5.3, Air for Combustion and Ventilation, of National
Fuel Gas Code ANSI Z223.1-latest edition, or applicable local
building codes. Canadian installations must comply with
CAN/CGA B149.1 or .2 Installation Codes.
Adequate combustion air and venti¬
lation openings must be provided to
assure proper combustion, prevent
possibility of flue gas spillage and
carbon monoxide emissions, causing
severe personal injury or death.
Boiler installation must assure sufficient openings in build¬
ing and boiler room to provide adequate combustion air and
ventilation. Consider construction tightness of building when
deciding whether additional outside openings may be needed.
Older buildings with single-pane windows, minimal
weather-stripping and no vapor barrier often provide enough
natural infiltration and ventilation without dedicated openings.
New construction or remodeled buildings are most often
built tighter. Windows and doors are weatherstripped, vapor
barriers are used and openings in walls are caulked. As a
result, such tight construction is unlikely to allow proper
natural air infiltration and ventilation.
Air from inside building (boiler in interior room):
• Tightly constructed buildings must be provided with open¬
ings to outside for combustion and ventilation air. These
openings must be sized to handle all fuel burning appli¬
ances, exhaust and ventilation fans and fireplaces.
• When openings to boiler room are taken to interior spaces,
provide two permanent openings: a combustion air opening
within 12 inches of floor and a ventilation opening within
12 inches of ceiling. Each opening must provide a minimum
free area of one square inch per 1,000 Btuh input of all
appliances in room plus requirements for any exhaust fans
in room. The interior space supplying combustion and ven¬
tilation air must have adequate infiltration from outside.
Air directly from outside to boiler room:
• Tightly constructed buildings must be provided with com¬
bustion air and ventilation openings to boiler room which
are adequate to handle the boiler needs plus the needs of
all other fuel-burning appliances, fireplaces and exhaust or
ventilation fans.
• Combustion and ventilation openings connecting directly
or by ducting to outside, or to attic or crawl spaces that
freely connect with outside, must be sized as follows:
1. Outside wall or vertical ducting - one square inch per
4,000 Btuh input of all appliances in room plus require¬
ments for any exhaust fans or other appliances in room.
2. Horizontal ducting - one square inch per 2,000 Btuh of
all appliances in room plus requirements for any exhaust
fans or other appliances in room.
3. All ducting must be same size as permanent openings.
Minimum area dimensions of ducting must be no less
than 9 square inches.
4. Other size ducting must comply with local codes.
CHIMNEY OR VENT REQUIREMENTS
Venting must be installed according to Part 7, Venting of
Equipment, of National Fuel Gas Code, ANSI Z223.1-latest edi¬
tion and applicable building codes. Canadian installations
must comply with CAN/CGA B 149.1 or .2 Installation Codes.
Minimum chimney or vent sizes sue on page 23 of these in¬
structions. A chimney or vent should extend at least 3 feet
above the highest point where it passes through a roof of a
building and at least 2 feet higher than any portion of a build¬
ing within a horizontal distance of 10 feet A chimney or vent
must not extend less than those distances stated above.
A lined chimney is preferred and must be used when required
by federal, provincial, territorial, state, or local building codes.
Vitreous tile linings with joints that prevent retention of mois¬
ture and linings made of noncorrosive materials are best.
Advice for flue connections and chimney linings can be
obtained from local gas utility. Type “B” vent material or single
wall vent pipe may be used.
Cold masonry chimneys, also known as outside chimneys, typ¬
ically have one or more walls exposed to outside air.
When any atmospheric gas-fired boiler with automatic vent
damper is vented through this type of chimney, the potential
exists for condensation to occur. Condensation can damage a
masonry chimney.
Weil-McLain recommends the following to prevent possible
damage:
1. Line chimney with corrosion-resistant metal liner such as
AL29^4C® single wall stainless steel or B-vent. Size liner
per National Fuel Gas Code ANSI Z223.1-latest edition.
2. Provide drain trap to remove any condensate.
Inspect existing chimney before
installing boiler. Failure to clean or
replace perforated pipe or tile lining
will cause severe ii\jury or death.
Do not alter boiler draft hood or place
any obstruction or non-approved
damper in breeching or vent system.
A.G.A./CGA certification will become
void. Flue gas spillage and carbon
monoxide emissions will occur causing
severe personal injury or death.
Where two or more gas appliances vent into a common chimney
or vent, equivalent area should be at least equal to area
of vent outlet on largest appliance plus 50 percent of vent outlet
area on additional appliance.
WHEN REMOVING BOILER
FROM COMMON VENTING SYSTEM:
WARNING
Failure to follow ail instructions listed
below can cause flue gas spillage and
carbon monoxide emissions, resulting
in severe personal injury, death or sub¬
stantial property damage.
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