Chimney & venting
Possible causes of insufficient draft;
A. Chimney Leaks - Air leaking in around a loose fit- ting cleanout door, flue pipe joints and/or seams not secured, improper plug openings or defective ma- sonry.
B. Chimney Too Short - The general rule for chimneys; 16 feet tall, three feet above the roof exit, and two feet taller than anything within ten feet.
C. Blocked Chimney - Have the chimney cleaned and inspected prior to installation and before each heating season.
D. Trees Or Other Topographical Barriers - Impeding on the chimney’s operation or causing a down draft situation. This can also be caused by adjacent build- ings or another roof of the same structure giving air currents a downward swirl.
NOTE: The chimney on the illustrated house is too low, it should be raised to compensate for down draft potential.
Wind direction
E. Chimney Size - The chimney can not be smaller than the flue exit from the appliance. Too large of a chimney could stay too cool to promote adequate draft.
F. Chimney Offsets - Offset chimneys should be avoided. The offset area can collect debris and cause a blockage.
G. Elbow restrictions - There should be no more than two 90° elbows or the equivalent used in connecting the stove to the chimney flue.
H. Shared Flue - No more than one appliance shall vent into a single flue.
The most common cause of poor draft is an improp- erly sized flue liner. It is recommended that the inside
dimensions of the liner be at least as large as the ap- pliance flue outlet and no larger than 125% of the col- lar for a round flue. An example, a 8” flue collar is 50 square inches. Increased by 25% would be 63 square inches, or approximately a 9” round flue. In general for round liners, it is recommended that they not be increased by more than one inch from that of the stove collar. This will help ensure proper draft with the lower flue temperatures.
REMEMBER; A solid fuel burning stove can only per- form as well as its venting system will allow it to.
THE MOST IMPORTANT THING TO REMEMBER ABOUT CHIMNEYS IS THEIR NEED FOR MAIN- TENANCE AND CLEANING. IF A CHIMNEY IS NOT CLEANED ON A FREQUENT BASIS, IT WILL AF- FECT THE DRAFT AS WELL AS BEING A CONTRIB- UTING CAUSE TO A POSSIBLE CHIMNEY FIRE.
IF YOU HAVE A CHIMNEY FIRE:
1.GET EVERYONE OUT OF THE HOUSE.
2.CALL THE FIRE DEPARTMENT.
3.CLOSE THE DRAFT CONTROL KNOBS ON THE STOVE.
DO NOT USE THE CHIMNEY UNTIL IT HAS BEEN THOROUGHLY CLEANED AND INSPECTED BY A QUALIFIED PERSON.
