Triple-wall metal chimney

Heating · Metal Chimneys or Vents · printed page 171 (PDF page 172)

Original page Sign in to save

Book index entries

Triple Wall Triple-Wall Triple-Wall Metal Chimney Metal Chimney Metal Vent

Text in the illustration

triple-wall chimneys use air rather than insulation to cool the outer walls of the chimney
this type of chimney is suitable only for zero clearance fireplaces - the flue would get too cool if used with a wood burning stove, causing creosote build-up
some triple-wall chimneys do not circulate air through the two outer chambers - insulation is provided by the "dead air" space
the inner lining is typically stainless steel while the outer walls can be stainless steel, aluminum or galvanized steel
exhaust gas
warm air out
cold air in
top of zero clearance fireplace
inner lining

Generated explanation

The illustration shows a sectional view of a triple-wall metal chimney extending from the top of a zero-clearance fireplace to a capped, screened termination. Exhaust gases rise through the central flue, while cold air enters at the top and descends through the outer chamber before turning upward through the adjacent chamber and exiting as warm air. The text explains that air cools the outer chimney walls and that some triple-wall designs instead use noncirculating, dead-air spaces. It identifies stainless steel as the typical inner lining material and stainless steel, aluminum, or galvanized steel as possible outer-wall materials. An annotation warns that using this chimney type with a wood-burning stove would overcool the flue and cause creosote buildup.