Burnham ES2 ES2 Manuel D'Instructions

  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 

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 

appliances installed in the same floorspace.

      

 

  In the table below, find the Minimum 

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.

      

 

  If the Floorspace from Step 1 is less than the 

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 

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 

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.

      

 

÷  

3000   BTU/hr/sq. in.

_____  (sq. in.)

  Duct this opening vertically or horizontally 

directly to the outdoors, or directly to a 

space that communicates directly with the 

outdoors, such as an attic or crawlspace.

Ceiling Height

7’

8’

9’

10’

Combined

Appliance

Input Rate

(see Step 2)

(BTU/hr)

50,000

357

313

278

250

100,000

714

625

556

500

150,000

1071

938

833

750

200,000

1429

1250

1111

1000

250,000

1786

1563

1389 1250

300,000

2143

1875

1667 1500

350,000

2500

2188

1944 1750

400,000

2857

2500

2222 2000

For more details and options, refer to your local 

building code, the National Fuel Gas Code (NFPA 
54 and ANSI Z223), and the Canadian Natural Gas 
Installation Code CAN/CGA-B149.1 or Propane 
Installation Code CAN/CGA-B149.2.