Utica Boilers SFE IV Steam Instruccion De Instalación

When the boiler is installed in a confined space and 

all air is provided from the outdoors, the confined 

space shall be provided with two permanent openings, 

one commencing within 12 inches from the top and 

one commencing 12 inches from the bottom of the 

enclosure. The openings shall communicate directly, or 

by ducts, with the outdoors or spaces (crawl or attic) 

that freely communicate with the outdoors. One of the 

following methods must be used to provide adequate 

air for ventilation and combustion.

A.  When directly communicating with the outdoors, 

each opening shall have a minimum free area of 1 

square inch per 4,000 BTU per hour of total input 

rating of all equipment in the enclosure. (Figure 

B.  When communicating with the outdoors by means 

of vertical ducts, each opening shall have a 

minimum free area 1 square inch per 4,000 BTU 

per hour of total input rating of all appliances in the 

enclosed space. (Figure #5)

C.  If horizontal ducts are used, each opening shall 

have a minimum free area 1 square inch per 2,000 

BTU per hour total input rating of all appliances in 

the enclosed space. (Figure #6)

D.  When ducts are used, they shall be of the same 

cross sectional area as the free area of the area of 

the openings to which they connect. The minimum 

dimension of rectangular air ducts shall not be less 

than 3 inches.

In calculating free area using louvers, grills or screens 

for the above, consideration shall be given to their 

blocking effect. Screens used shall not be smaller than 

1/4 inch mesh. If the free area through a design of 

louver or grill is known, it should be used in calculating 

the size opening required to provide the free area 

specified. If the design and free area is not known, it 

may be assumed that wood louvers will have 20-25% 

free area and metal louvers and grills will have 60-75% 

free area. Louvers and grills shall be fixed in the open 

position or interlocked with the boiler so that they are 

opened automatically during boiler operation.