Beckett CG4 - Manual (Page 8)

8
Section: INSPECT/PREPARE INSTALLATION SITE
Combustion Air Supply
Some local codes and
gas utilities require the
installation of a CO detector, this is
strongly recommended in all
applications.
Carbon Monoxide
Hazard
Do not block combustion air inlet. Failure to
provide adequate air supply could seriously affect
the burner performance and result in damage to
the equipment and emission of poisonous carbon
monoxide gas.
Buildings with Adequate Air Infiltration
In many cases, a burner operating in an unconfined
space of a conventional frame, brick or stone building
will receive adequate air supply from leakage in the
building itself. But if the burner is located in a confined
space such as a furnace or boiler room, that space
must have one permanent opening toward the top of the
space and one near the bottom of the space.
Each opening must have a free area of not less than one
sq. in. per 1,000 BTU per hour of the highest input rating
listed for the appliance (refer to NFPA 54 & 58).
Remember to take the total input of all air-using
appliances into consideration when figuring the
openings. The openings must connect with the inside of
the building, which should have adequate infiltration from
the outside.
As an example:
If a gas burner was firing at 175,000 BTU/Hr and a water
heater was firing at 70,000 BTU/Hr, in an enclosed room
in a building each opening in the enclosure should be
245 sq. in. (245,000/1,000 x 1 sq. in. = 245 sq. in.) A
245 sq. in. opening would typically be 10” x 25” or 16” x
16”.
Buildings with Less Than Adequate Air
Infiltration
If the burner is located in a tightly constructed building
where there is inadequate outside air infiltration, outside
combustion air must be supplied by some other means.
Figure 5 – Outdoor Air Ducted to Burner
One method to accomplish this is through a permanent
opening(s) in an exterior wall. The opening, or openings,
must have a total free area of not less than one sq. in.
per 5,000 BTU per hour. All appliances must be taken
into consideration. Refer to NFPA 54 & 58.
Another method is to supply outside air directly to the
burner through round, smooth duct work (See Figure
5). Some manufacturers offer accessories which allow
outside combustion air duct work to be coupled to the
burner. These kits must meet the engineered system
requirements of NFPA54. For safety reasons it is
important that you comply strictly with their installation
instructions.
Clearances to Burner and Appliance
○ Provide space around burner and appliance for easy
service and maintenance.
○ Check minimum clearances against those shown
by the appliance manufacturer and by applicable
building codes.
○ The recommended clearance around the burner
itself is 12” minimum for service access.