It is not unusual to find an opening into a chimney other than for the
smoke pipe of the main heating apparatus. This is a frequent cause of
unsatisfactory operation. No range, stove, fireplace, or ventilating
register should be connected with the chimney flue built for the heating
apparatus. If it should be desired to use an existing abandoned fireplace
chimney for a range or stove the fireplace flue should be closed tight
about a foot below the place where the smoke pipe enters.
[Illustration: Fig. 6.--A division wall of at least 4 inches of brick
should separate each flue from any others in the same chimney. Either of
the arrangements shown will produce a good bond.]
There should be but one connection with a flue, if for no other reason
than to decrease the fire hazard. Fires frequently occur from sparks
that pass into the flue through one opening and out through another. Two
stoves, one on the first floor and one on the second, may be connected
with the same chimney flue, but if the fire in the upper stove is hotter
than in the lower, the lower will have practically no draft.
A soot pocket provided with a door for cleaning it out is very
convenient. The door should be placed just below the smoke pipe opening,
and care must be taken to see that it fits snugly and is always closed so
tight that no air can get in.