Model G3B Gas burner — Instruction manual
MNG3B Gas 041015
5
1. Prepare Site • Prepare Burner • Mount Burner
(continued)
Inspect installation site
Combustion/ventilation air openings
Installing the burner/appliance in a space that does not provide
enough air for combustion and ventilation can result in severe
personal injury, death or substantial property damage. Follow
all applicable codes and guidelines below to ensure space has
sufficient air openings.
Large spaces
For appliances located in basements, ventilated crawl spaces or other large
areas, no additional air openings should be necessary.
Exception
: If the building construction is unusually tight (see National Fuel
Gas Code or CSA B149.1 or .2 for definition), you will need to provide air
openings into the building if appliance air comes from inside. Provide one
opening within 12 inches of the ceiling, and one opening within 12
inches of the floor. Size each opening to provide free area (after deduction
for louvers) of 1 square inch per 1,000 Btuh input of all fuel-burning
appliances in the building.
Confined spaces — air from inside building
If air openings connect to areas inside the building, provide two openings,
one within 12 inches of the ceiling, the other within 12 inches of the floor.
Each opening must have a free area (after deduction for louvers) of 1 square
inch per 1,000 Btuh of all appliances in the space. If the building construc-
tion is unusually tight (see National Fuel Gas Code or CSA B149.1 or .2 for
definition), you will need to provide air openings into the building. Provide
two openings sized and located as for the openings into the boiler space.
Confined spaces — air from outside
If air openings connect directly to outside, provide two openings, one within
12 inches of the ceiling, the other within 12 inches of the floor. Each opening
must have a free area (after louver deduction) of:
• If directly through side wall: 1 square inch for each 4,000 Btuh of all
appliances in the space.
• If through vertical ducts: 1 square inch for each 4,000 Btuh of all
appliances in the space.
• If through horizontal ducts: 1 square inch for each 2,000 Btuh of all
appliances in the space.
Verify openings
When sizing air openings for combustion and ventilation, include
air required for exhaust fans and other appliances, such as
clothes driers, that require air for operation.
Check appliance manual and applicable codes for required sizing of
combustion and ventilation air openings.
• Verify that openings are unobstructed.
• Verify that appliance space and air source spaces are free of:
– gasoline or other flammable liquids or vapors.
– combustible materials.
– air contaminants, such as laundry products, paint, thinner, varnish, etc.
• Confirm with user that the area will be kept free of these materials at
all times.
Figure 2
Locating & sizing air openings