Appendices: A - Combustion Air - Burnham ES2 ES2 Installation & Service Instructions Manual

PROVIDE ENOUGH AIR to ventilate the
boiler room, dilute the flue gases, and
sustain combustion. Ignition failure, overheating,
fire, carbon monoxide, and spillage of flue gases
may result from poor air supply.
If the boiler is a Direct Vent boiler and exchanges
all combustion air and combustion products
directly with the outdoors, there are no special
requirements for providing combustion, ventilation,
and dilution air.
If the boiler is chimney vented, power vented or
induced draft and draws combustion air from within
the building, follow the steps below to determine
how to provide air to the boiler.
Is the boiler located in a confined space?:
Calculate the floorspace (in square feet) of
1.
the boiler room and all rooms connected
to the boiler room by passageways not
furnished with doors.
___________ floorspace (sq. ft.)
Add up the input rates of all the combustion
2.
appliances installed in the same floorspace.
___________ input (BTU/hr)
In the table below, find the Minimum
3.
Allowable Floorspace based on the
Combined Input Rate from Step 2 and the
ceiling height. If the Combined Input Rate
is between two rates, use the next highest
rate.
___________ floorspace (sq. ft.)
Minimum Allowable Floorspace in the Boiler Room
and Freely Connected Rooms (sq. ft.)
50,000
100,000
Combined
150,000
Appliance
200,000
Input Rate
250,000
(see Step 2)
300,000
(BTU/hr)
350,000
400,000
32
APPENDIX A – COMBUSTION AIR
combined appliance
minimum allowable
Ceiling Height
7' 8' 9'
357 313 278
714 625 556
1071 938 833
1429 1250 1111
1786 1563 1389
2143 1875 1667
2500 2188 1944
2857 2500 2222
If the Floorspace from Step 1 is less than the
4.
Minimum Floorspace from Step 3, then you
must provide outdoor air to the boiler room.
Proceed to Step 6.
Is the boiler located in a building of unusually tight
construction?
If the answer to all of the three questions
5.
below is "yes", then you must provide
outdoor air to the boiler room.
Do the walls and ceilings exposed to the
outside atmosphere have a continuous
water vapor retarder with a rating of 1 perm
or less, with openings gasket or sealed?
 Yes  No
Are operable windows and doors
weatherstripped?
 Yes  No
Are exterior wall joints caulked or sealed?
 Yes  No
If you must provide outdoor air to the boiler
6.
room, the top of the permanent opening
into the boiler room must be within 12" of
the ceiling, and the free area of the opening
(sq. in.) must be no less than the Combined
Appliance Input (from Step 2) divided by
3000 BTU/hr/sq. in.
__________ input (Step 2)
÷
Duct this opening vertically or horizontally
7.
directly to the outdoors, or directly to a
space that communicates directly with the
outdoors, such as an attic or crawlspace.
10'
250
500
750
For more details and options, refer to your local
1000 building code, the National Fuel Gas Code (NFPA
54 and ANSI Z223), and the Canadian Natural Gas
1250
Installation Code CAN/CGA-B149.1 or Propane
1500
Installation Code CAN/CGA-B149.2.
1750
2000
combined appliance
3000 BTU/hr/sq. in.
Minimum Opening Size
_____ (sq. in.)