Square Base Chimney Caps

The FAMCO Square Base Vacuum Cap (GSQ) has been used for decades with gas, oil, coal and wood burning chimneys. This chimney cap increases updraft and prevents downdrafts caused from wind or insufficient air draws. The Vacuum Cap works by forcing the wind to alter its direction over one of three gores on the cap. This change of direction creates an area of lower density air (partial vacuum) at the outlet of the pipe. This lower density air creates draft within the exhaust pipe, helping to remove exhaust gases and increasing overall efficiency. The positioning of the cap relative to the prevailing winds is not critical but is slightly more effective when placed with its flat side facing the winds. This Vacuum Cap should be used for installation over the outside diameter of a square tile.