Beckett SM - Manual (Page 6)

6
Inspect chimney or direct vent system
Starting with minimum gph fi ring rate, the minimum
size recommended is 6” fl ue pipe with 8” X 8”
inside chimney, unless specifi ed otherwise by the
appliance manufacturer.
A chimney fl ue shall extend at least 3 feet above
the highest point at which the chimney comes in
contact with the roof, and not less than 2 feet above
the highest roof surface or structure within 10 feet
horizontally of the chimney. Refer to Figure 2.
Any accumulation of soot or debris in chimney
offsets should be removed.
Any obstructions such as a protruding joint or a
piece of broken tile wedged in the chimney should
be removed.
No other appliance connection should be made to
the same fl ue pipe.
The fl ue pipe should have an upward pitch toward
the chimney of at least 1/4” per foot of length. It
should fi t tightly and should not project into the
chimney.
Any leakage between tiles, around clean-out doors,
or around the vent pipe should be sealed.
INSULATED STAINLESS STEEL CHIMNEY LINERS
The new designs of high effi ciency oil furnaces and
boilers in conjunction with fl ame retention oil burners
are more effi cient. One result of increased effi ciency is
lower fl ue gas temperatures. As fl ue gases rise in the
chimney, they will cool and condense when they reach
the dew point. The condensation will mix with the sulphur
in the fl ue gases creating sulphuric acid. The acid will
attack the chimney mortar, brick and clay liners causing
corrosion, deterioration and blockage of the chimney.
Eventually the blockage could prevent exhausting the
fl ue gases. Instead, the fl ue gases could vent out the
barometric damper into the living space.
1.
2.
3.
4.
5.
6.
7.
Therefore, it is strongly recommended that an approved
insulated stainless steel liner be installed.
For those installations not requiring a chimney, such
as through-the-wall vented appliances, follow the
instructions given by the appliance and power venter
(if used) manufacturers.
Combustion air supply
See NFPA 31 Standard for complete details.
○
Appliance located in confi ned space
The confi ned space should have two (2) permanent
openings: one near the top of the enclosure and one
near the bottom of the enclosure. Each opening shall
have a free area of not less than (1) one square inch
per 1,000 BTU’s per hour of the total input rating of all
appliances within the enclosure. The openings shall
have free access to the building interior, which should
have adequate infi ltration from the outside.
Section: Inspect/Prepare Installation Site
Figure 2 - Chimney Design - Above the Roof
Minimum Clearence: 2 FT.
NOTE: Correct
chimney design is
shown by dotted lines.
Incorrect chimney
design, as shown by
the solid lines, may
result in down-drafts.
Adequate Combustion
and Ventilation Air Supply
Required
Failure to provide adequate air supply could
seriously affect the burner performance and result in
damage to the equipment, asphyxiation, explosion or
fi re hazards.
The burner cannot properly burn the fuel if it is not
supplied with a reliable combustion air source.
Follow the guidelines in the latest editions of the
NFPA 31 and CSA-B139 regarding providing
adequate air for combustion and ventilation y
y