5
TABLE 1
Minimum Installation clearances from combustible materials
LOCATION
APPLICATION
CCC-A
MBP1-A, MBPF-A, MBP2-A and
MBP-U
Furnace
6”
6”
Side
Supply plenum, warm air duct within 6 ft of furnace
1”
3”
Other side
Furnace
24”
24”
Back
Furnace (filter side)
24”
24”
Top
Horizontal warm air duct within 6 ft of furnace
1”
3”
Bottom
Furnace (Non Combustible floor)
0”
0”
Horizontally or below flue pipe
9”
9”
Flue pipe
Vertically above pipe
9”
9”
Front
From Burner
24”
24”
1.3.1) Location
Locate the furnace as closely as possible to the chimney or vent
terminal, providing ample clearance to permit easy accessibility for
cleaning the inside of the furnace, the removal of filters, blower,
motors, controls and flue connections. The furnace may be installed
on a combustible floor.
1.4)
VENTING
The furnaces can be vented with a chimney or with a power venter
and must be operated at a negative overfire draft and stack draft. A
barometric damper must be used.
WARNING
Poisonous carbon monoxide gas, fire and
explosion hazard.
Read and follow all instructions in this section.
Failure to properly vent this furnace can result in
property damage, personal injury and/or death.
WARNING
Poisonous carbon monoxide gas hazard.
Never install a hand operated damper in the vent
pipe. However, any Underwriters Laboratories listed
electrically operated automatic type vent damper
may be installed if desired. Be sure to follow
instructions provided with vent damper. Read and
follow all instructions in this section.
Failure to properly vent this furnace or other
appliances can result in property damage, personal
injury and/or death.
The oil furnaces, when set up for chimney venting, are certified for use
with L-vent, A-vent, tile-lined and metal-liner-tile-lined chimneys, and
can be vented with a barometric draft damper.
The appliance may be installed in a chimney of the proper size and
adequate chimney base temperature as specified in the Installation
Code. Since a barometric damper is used, the basement air entering
the damper reduces the possibility of vent condensation. The relevant
excerpt from the code is found in this section - Use it as a guide when
local or national codes do not exist. To increase the chimney base
temperature, add a vent connector insulation or decrease fan speed to
solve this problem. All parameters must be verified with respect to this
Instruction Manual.
CAUTION
When the furnace (chimney installation) is co-vented
with other combustion appliances such as a water
heater, the allowable venting materials (L-Vent etc.) for
use with those appliances should also be investigated.
Flue pipe sizing
The following table is an except from the installation code and
indicates permitted flue sizes and minimum base temperatures for
circular flues in chimney with a thermal resistance of less than R6 (6
ft
2
•
hr
•°
F/Btu). Where a new appliance, burner, or chimney is
installed, chimney vent sizes and flue-gas temperatures shall comply
with Table 2 (measured at the chimney connector with the barometric
damper shut, if applicable, after 5 minutes of operation).
NOTES
: Thermal resistance values for typical chimneys
are as follows:
R2 (2 ft
2
•
hr
•°
F / Btu):
clay -lined masonry, A -vent
R3 (3 ft
2
•
hr
•°
F / Btu):
metal liner in clay-lined
Masonry
R6 (6 ft
2
•
hr
•°
F / Btu):
metal or clay-lined masonry
with R4.5 (4.5 ft
2
•
hr
•°
F / Btu)
insulation between liner and
masonry (e.g. 2 in. of
expanded mica or 1 3/8 in. of
high density glass fibreboard.)
Applying Table 2
If a furnace with a 0.60 USGPH nozzle is to be connected to a 20 foot
tall clay -lined masonry chimney, the thermal resistance of this chimney
type is R2, which is less than R6. The actual firing rate at 156 psig is
1.25 x 0.60 = 0.75. Therefore this table shall apply as follows:
The minimum size permitted shall be 4 inches, inside diameter;
The maximum size permitted shall be 5 inches, inside diameter;
The minimum base temperature shall be about 320º F (160
o
C).
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