Fresh Air For Combustion - Dunkirk XEB-2 Installation Manual

Base part number. We use a 2" Cladlite pad as
a combustible floor base. These are available
from your local supplier. Use 24" x 30" pad for
2-5 section boilers, and a minimum 30" x 30"
pad for 6-7 sections boilers. The boiler must be
centered on the combustible floor base.
Provision for combustion and ventilation air
must be in accordance with the National fuel Gas
Code, ANSI Z223.1- latest revision, or applicable
provisions of the local building codes.
WARNING
!
Be sure to provide enough fresh air for
combustion. Enough air insures proper
combustion and assures that no hazard will
develop due to the lack of oxygen.
You must provide for enough fresh air to assure
proper combustion. The fire in the boiler uses
oxygen. It must have a continuous supply. The air
in a house contains only enough oxygen to supply
the burner for a short time. Outside air must enter
the house to replace that used by the burner. Study
following examples 1 and 2 to determine your fresh
air requirements.
EXAMPLE 1: Boiler Located In Unconfined Space
An unconfined space is defined as a space whose
volume is not less than 50 cubic feet per 1,000 Btu
per hour of the total input rating of all appliances
installed in that space.
If your boiler is in an open area (un-partitioned
basement) in a conventional house, the air that leaks
through the cracks around doors and windows will
usually be adequate to provide air for combustion.
The doors should not fit
cracks around the windows.
Equipment located in buildings of tight construction
shall be provided with air for combustion, ventilation,
and dilution of flue gases using the methods
described in example 2b or shall be specially
engineered. The authority having jurisdiction must
approve specially engineered installations.
loCAtING the BoIleR

fReSh AIR foR ComBuStIoN

!
tightly. Do not caulk the
.
8. The boiler shall be installed such that the automatic
gas ignition system components are protected
from water (dripping, spraying, rain, etc.) during
appliance operation and service (circulator
replacement, control replacement, etc..)
NOTE: If you use a fireplace or a kitchen or bath-
room exhaust fan, you should install an outside
air intake. These devices will rob the boiler and
water heater of combustion air.
EXAMPLE 2: Boiler Located In Confined Space
A. All Air From Inside The Building: The confined
space shall be provided with two permanent
openings communicating directly with an additional
room(s) of sufficient volume so that the combined
volume of all spaces meets the criteria for an
unconfined space. The total input of all gas utilization
equipment installed in the combined space shall
be considered in making this determination. Each
opening shall have a minimum free area of one
square inch per 1,000 Btu per hour of the total input
rating of all gas utilization equipment in the confined
space, but not less that 100 square inches. One
opening shall be within 12 inches of the top and one
within 12 inches of the bottom of the enclosure. The
minimum dimension of air openings shall not be less
than 3 inches (see Figure #3A).
5
Figure #3A