Page 14
Biasi SG Pro Series
6. Intake Venting
1. Be certain adequate air is available for combustion and ventilation.
a.) Boiler located in unconfined space:
Installation in large areas, such as basements can usually be assumed to provide
sufficient air. An unconfined space is defined as having an area of greater than 50
square feet for every 1000 Btuh of input.
b.) Boiler located in confined space:
If all air for combustion and ventilation is to come within the building: Two (2)
openings shall be provided with one (1) opening commencing within 12 inches of the
top and one (1) opening commencing within 12 inches of the bottom of the enclosure.
These openings shall not be located closer than 3 inches from either the top or bottom
of the enclosure and shall be open to areas connecting freely with the outdoors. The
area of each opening shall not be less than one square inch per 1000 BTU/HR. of total
input rating of all appliances within the enclosure; with a minimum of 100 square inches
for each opening.
If all the air for combustion and ventilation is to come from outside the building;
two (2) openings shall be provided with one opening commencing within 12 inches of
the top and an opening commencing within 12 inches of the bottom of the enclosure.
These openings shall not be located closer than 3 inches from either the top or bottom
of the enclosure, and shall connect directly or by ducts with the outdoors. The area of
each opening shall be equal to one square inch per 2000 BTU/HR of total input rating.
If ducts are used to convey the air, vertical ducts require areas of one square inch per
4000 BTU/hr horizontal ducts require one square inch per 2000 BTU/hr. Ducts shall
have the same cross sectional area as the full area of the openings to which they
connect.
The upper opening is essential for maintenance of proper circulation of air with
the boiler and reasonable ambient temperature in order to maintain proper control
temperatures. When a duct is used for ventilation, check for louver free net area and
correct for screen resistance to ensure that the ventilation area has been satisfied. DO
NOT INSTALL THE BOILER UNTIL PROPER COMBUSTION AIR HAS BEEN
ARRANGED.
c.) Boiler located in a room under negative pressure:
If the boiler is to be installed within a home where the operation of exhaust fans, attic
fans, kitchen ventilation systems, clothes dryers or fireplaces may create severe
negative vent pressures causing unsatisfactory combustion and venting, special
provisions should be made for additional make-up air to supply the other air
requirements. If building is of tight construction, combustion air requirements may not
be met and combustion air ducts from outside may be necessary. Please refer to NFPA
No. 31.
Summary of Contents for SG-3
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Page 33: ...Biasi SG Pro Series Page 33 Notes...
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