Lennox Hearth Brentwood SP - Manual (Page 4)

Building a Fire
(starting and maintaining a fire)
To start a fire, place several crumpled up balls of
newspaper in the firebox. Place small dry pieces
of kindling on top of the paper, criss-crossing
the kindling so that there are air spaces in be-
tween. Keep the fuel far back enough so that air
can get underneath. Open the air controls fully
and light the newspaper. Once the newspaper
and the kindling is well ignited, close the door.
Once the kindling fire is well established, cord
wood can be added (see Primary Air Combus-
tion Control section for proper operation of the
air controls).
The unit will burn best with 2-3 pieces of cord
wood spaced 1 to 2 inches apart and allowing
air to get under the fuel. Criss-crossing or ar-
ranging the fuel so that air can get underneath,
will help the fire to get started easily. The unit
should be operated with the air control fully
open long enough to get the cord wood well
ignited.
COMBUSTION CONTROLS
Primary Air and Air Boost Controls
There is no flue damper in the Brentwood™
fireplace. As is common with air tight stoves,
the combustion air control sets the flow of air
entering the firebox. This allows for a more
precise control of the fire. The combustion air
control is located below the door on the left side.
The main source of air (primary air) entering
the firebox can be diminished by moving the
air combustion control from left to right. The
primary air is fully opened when the air control
is completely moved to the left. The air control
device can also be used to add an extra boost of
air especially during fire start up and reloading
of the unit. Pulling the air combustion control
will induce an air boost at the base of the fire
allowing an easier fire start up. When the fire is
well established, the control can be pushed in
to shut down the air boost allowing for a longer
burn time. The combustion air control should
be in the closed position (primary air and air
boost) when the fireplace is not in use. This
will minimize air leakage up the chimney. The
combustion air control should be opened before
opening the door to minimize the possibility of
back draft coming into the room.
Accelerated Combustion
The maximum heat output for the Brentwood™
fireplace is achieved by burning with the door
closed and the combustion air opened and
pulled out. By this method, the Brentwood
fireplace can produce up to 55,000 BTU of
heat per hour. However, it will be necessary
to reload with wood every one or two hours.
This is the least efficient method of burning the
Brentwood fireplace.
Use caution when firing with the combustion
air control wide open. Only burn cord wood in
this manner. Small dry pieces of softwood and
construction scraps will burn very intensely us-
ing this method and may damage the firebox.
Medium Combustion
This is the recommended mode of operating
the Brentwood fireplace and should be the
one normally used since it will deposit the
least amount of creosote on the glass and
in the chimney. The combustion air control
must be 3/4 closed and pushed in to close the
air boost. The precise setting will depend on
many factors, including chimney length and the
moisture content of the wood.
For instance, a long chimney will necessitate
closing the damper more. To obtain the proper
combustion, close the damper completely, then
open it about 1/4” to 1/2”. Three medium size
pieces of wood should be burning on a bed of
hot coals. The heat output will be approximately
30,000 BTU per hour and the loading time will
be about every 3-4 hours. Softwoods may be
burned using this method but the time will be
substantially reduced.
Slow Combustion
When the air combustion control is completely
closed, the fireplace is in a slow combustion
phase. If the hearth is hot enough, slow combus-
tion will not extinguish the fire, but there will be
a noticeable change in the flame pattern. The
flames will be slow and may appear dirty if the
wood is too wet (moisture content of 20% and
more). Do not allow the wood to burn without
flame, since this will produce excessive creosote
in the unit.
Figure 1
Creosote may accumulate on the glass door.
This method of burning should be used only
after operating the Brentwood fireplace with
the air control opened to produce a hot fire for
about an hour or at medium pace for at least
three (3) hours. Slow combustion can be used
at night in order to reduce the heat output and
to prolong the burn. The loading time will be
between 6-8 hours.
REFUELING FOR BEST PERFORMANCE
The Brentwood fireplace will operate best if
attention is given to operating the unit with the
damper fully opened after refueling in order
to bring the firebox and the chimney system
up to their optimum operating temperature.
Combustion efficiency is relative to firebox
temperature. A temperature of 500º C (932º F)
and up, with a visible flame, in the upper part
of the firebox indicates a maximum efficiency.
To obtain this temperature, the fireplace must
be operated with the primary air and air boost
controls fully opened during 10 to 20 minutes
after reloading, depending on the heat and on
the moisture content of the wood.
Once you have reached the desired temperature,
the air boost can be closed and the primary air
set to a medium setting. You know you have
reached the desired temperature when, closing
the primary air control, you can see a flame
at the top of the firebox. The benefit of this
technique will be cleaner glass, less creosoting,
greater efficiency and the most pleasing fire for
your enjoyment.
SMOKING –
CAUSES AND TROUBLESHOOTING
To reduce the likelihood of smoking when open-
ing the door, set the combustion air controls to
the left before opening the door. Your fireplace
has been designed and tested to provide smoke
free operation. Occasionally, there may be a
small amount of smoking upon lighting the fire,
until the chimney heats up but this should not
continue. If the fireplace continues to smoke it
is probably for one of the following reasons:
A. Negative pressure in the house
As the fire burns, air goes up the chimney.
This air must be replaced through leakage
into the house or through the outside air duct.
When operating the Brentwood fireplace,
open a nearby window temporarily to check if
there is adequate replacement air supply.
Slow
Push to Close
Air Boost
Pull to
Open
Air Boost
Medium
Accelerated
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
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