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stack effect[′stak i‚fekt]
The pressure difference between the confined hot gas in a chimney or stack and the cool outside air surrounding the outlet.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
Also referred to as the chimney effect, this is one of three primary forces that drive air leakage in buildings. When warm air is in a column, such as a building, its buoyancy pulls in the colder air that is low in buildings, as the buoyant, warmer air exerts pressure to escape out the top. The pressure of stack effect is proportional to the height of the column of air and the temperature difference between the air in the column and ambient air. Stack effect is much stronger in cold climates during the heating season than in hot climates during the cooling season.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
chimney effect, flue effect, stack effect
The tendency of air or gas in a shaft or other vertical passage to rise when heated, owing to its lower density compared with that of the surrounding air or gas.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.