Hot-and-cold logic (From Bradford Telegraph and Argus)

Hot-and-cold logic

8:52am Friday 3rd February 2012 in Readers' letters By Telegraph & Argus

Sir – Harry Lingard’s letter ‘A waste of energy’ (T&A, January 30) bemoans as energy-wasting a shop leaving its door fully open. Also a bank that has got rid of its lobby and is letting its heat spill out into the street.

I feel that far from the designers of these projects being fools, they are in fact practising the use of up-to-the minute, scientifically-proven energy-saving design for big buildings with a large footfall.

You remove lobbies to keep the air circulation clear and maintain pressure equilibrium between the building and outside.

Hot and cold don’t readily mix, so by placing a hot jet of air blowing down over an open doorway the hot air will roll into the building and the cold outside air is deflected back out.

This is the same logic that requires radiators in the home be placed under the windows.

Tony Greenbank (heating engineer), Mainspring Road, Wilsden