[CHIMNEYS AND FIREPLACES.]

A. M. Daniels, Assistant Mechanical Engineer, Division of
Agricultural Engineering, Bureau of Public Roads.

[CONTENTS.]

Page.Page.
Chimneys: Function of chimneys [3] The chimney draft [4] Shapes and sizes of flues [5] Height of chimney [7] Flue linings [7] Location and wall thickness [8] Openings into the chimney [10] Supporting the chimney [10] Capping the chimney [12] Chimney and roof connections [12] Chimney connections [12] Chimney insulation [14] Smoke test for leakage [14] Cleaning and repairing the flue [15] Fireplaces: Essentials of fireplace construction [15] Area of the flue [16] The throat [17] Smoke shelf and chamber [18] Shape of fireplace [19] Throat damper [19] Placing the throat damper [20] Size of fireplace opening [20] Depth of fireplace opening [20] The hearth [21] The jambs [21] Fireplace back and sides [21] Supporting irons [21] Improving fireplace heating [22]
Chimneys:
Function of chimneys[3]
The chimney draft[4]
Shapes and sizes of flues[5]
Height of chimney[7]
Flue linings[7]
Location and wall thickness[8]
Openings into the chimney[10]
Supporting the chimney[10]
Capping the chimney[12]
Chimney and roof connections[12]
Chimney connections[12]
Chimney insulation[14]
Smoke test for leakage[14]
Cleaning and repairing the flue[15]
Fireplaces:
Essentials of fireplace construction[15]
Area of the flue[16]
The throat[17]
Smoke shelf and chamber[18]
Shape of fireplace[19]
Throat damper[19]
Placing the throat damper[20]
Size of fireplace opening[20]
Depth of fireplace opening[20]
The hearth[21]
The jambs[21]
Fireplace back and sides[21]
Supporting irons[21]
Improving fireplace heating[22]

FUNCTION OF CHIMNEYS.

HE prime function of a chimney is to produce a draft that will cause sufficient combustion and carry off the resulting smoke; incidentally it assists ventilation. Many unsatisfactory heating plants and much excessive fuel consumption are due to improperly constructed chimneys, which are the rule rather than the exception. Although many of these are more inefficient than dangerous, yet reports of the National Board of Fire Underwriters[1] show that a larger number of fires are caused by defective chimney construction than by anything else. The annual loss resulting from such fires is greater than the fire loss from any other cause. Poor chimney construction is responsible for smoke pollution of the air, waste of fuel, and poor heating.