9
Medium combustion
This is the recommended mode of operating the BIS
ULTRA 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 damper must be 3/4 closed.
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 ½" to ¾". 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 damper is closed, the fireplace is
in a slow combustion phase. Slow combustion will not
stop 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).
Creosote may accumulate on the glass doors. This method of burning should be used only after
operating the BIS ULTRA with the air control opened to produce a hot fire for about an hour. 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 6-10 hours.
Refueling for best performance
The BIS 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 and up in the upper part of the firebox indicates a maximum efficiency. To obtain this
temperature, the fireplace must be operated with the damper fully opened during 15 to 30 minutes
after reloading, depending on the heat and on the moisture content of the wood. Once you have
reached the desired temperature, the damper can be closed gradually.You know you have reached
the desired temperature when, closing the damper, 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. If your fireplace is equipped with a central forced air system,
make sure the central blower is turned off during reloading to avoid smoking problems.
