Exhaust Venting - Biasi B-3 Manual And Installation Instructions

The B10 boiler is a high efficiency unit that requires proper venting. The boiler must
be vented to the outdoors by means of a tile lined masonry or a approved pre-fabricated
chimney of the size and height recommended by the manufacturer or by a listed "power
venting" unit which provides draft by mechanical means. In many installations, particularly
older interior and most exterior chimneys, a corrosion resistant liner should be installed and
may be required by code. Please consult the liner manufacturer for the appropriate chimney
liner.
The flue-gas exit of the chimney must be located at least 24 inches above any part of
the building structure within 4 feet of the chimney. Be sure the chimney and smoke pipe
won't become obstructed by squirrels, bird nests, soot buildup, chimney liner deterioration,
etc.. If using a "power venter" system, it is suggested that it should be installed on the
leeward side of the house. (Please consult with the manufacturer of "power venter" for
requirements concerning clearances from combustibles and distances from doors and
windows.) The "venter" must be installed by a licensed burner mechanic and done in
accordance with local codes. This is a very low stack temperature boiler (350F gross temp.)
so caution should be used when connecting to an outside built chimney. Should you have
concern that the flue gases could condense, you should consider lining the chimney or
using a listed, "power venting" or the QHT direct vent system. If "power venting" is used to
discharge flue gases, then the power vent unit should be equipped with a postpurge control
such as a delay-off, timing control to prevent problems with fogging and nozzle post drip. If
the boiler is installed as a direct vent unit, it must be installed using the DVH-5 direct vent kit
supplied by QHT Inc.
The exhaust pipe connection from the boiler to the chimney should be as short as
possible, with a minimum number of elbows. The vent pipe must have a vertical rise of at
least 1/4 inch per foot of horizontal run. The vent pipe must be of the same diameter as the
flue outlet on the boiler. The chimney connector should have a minimum thickness of 26
gauge, corrosion resistant (galvanized) steel, and be assembled with a minimum of three (3)
sheet-metal screws in each joint. In some one and two story houses, a barometric draft
control is not required as the B-10 is designed to be pressure-fired. However in high draft
situations which exceed the flue gas resistance through the boiler, a barometric draft control
is recommended. The over fire draft should be positive and between 0 and .06 inches of
water column. The draft at the breech should be enough to overcome the resistance
through the boiler.

7. Exhaust Venting

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