Burnham 1100-H4 User Manual

c.  Horizontal ducts. Minimum free area of one (1) 

square inch per 2,000 Btu per hour input of all 

equipment in space. Duct cross-sectional area 

shall be same as opening free area.

 

Alternate method for boiler located within 

confined space. Use indoor air if two permanent 

openings communicate directly with additional 

space(s) of sufficient volume such that combined 

volume of all spaces meet criteria for unconfined 

space. Size each opening for minimum free area 

of one (1) square inch per 1,000 Btu per hour 

input of all equipment in spaces, but not less than 

100 square inches.

7.  Combustion Air/Ventilation Duct Louvers and 

Grilles. Equip outside openings with louvers to 

prevent entrance of rain and snow, and screens to 

prevent entrance of insects and rodents. Louvers and 

grilles must be fixed in open position or interlocked 

with equipment to open automatically before burner 

operation. Screens must not be smaller than ¼ inch 

mesh.

  Consider the blocking effect of louvers, grilles and 

screens when calculating the opening size to provide 

the required free area. If free area of louver or grille 

is not known, assume wood louvers have 20-25 

percent free area and metal louvers and grilles have 

60-75 percent free area.

  Move boiler to approximate installed position.

  Remove all crate fasteners.

  Lift and remove outside container.  Save two of the 

wooden slats from the container sleeve for use in Steps 

E and F.

  Remove all boiler hold-down fasteners.

  Tilt the boiler to its front side or back side and slide a 

wooden slat under the three raised feet.

  Tilt the boiler in the opposite direction and slide 

another wooden slat under the three raised feet.

  Slide the boiler left or right off the skid using the two 

wooden slats as runners.

  Move boiler to its permanent location.

6.  For boiler located within unconfined space in building 

of unusually tight construction or within confined 

space, provide outdoor air through two permanent 

openings which communicate directly or by duct 

with the outdoors or spaces (crawl or attic) freely 

communicating with the outdoors. Locate one opening 

within twelve (12) inches of top of space. Locate 

remaining opening within twelve (12) inches of bottom 

of space. Minimum dimension of air opening is three 

(3) inches. Size each opening per following:

a.  Direct communication with outdoors. Minimum 

free area of one (1) square inch per 4,000 Btu per 

hour input of all equipment in space.

b.  Vertical ducts. Minimum free area of one (1) 

square inch per 4,000 Btu per hour input of all 

equipment in space. Duct cross-sectional area 

shall be same as opening free area.