DIYbanter - View Single Post

Andy Champ[_2_]

wrote:

I've lived in houses with sash windows all my life, I randomly open
top or bottom, and I can't say I've ever noticed it makes one jot of
difference which you choose. I think some overanalysis is going on
here.

Dead right - but for the wrong reason. It's not so much _which_ windows
you open but _when_. Close them, and the curtains, all day, to keep the
heat out; open them at night when the outside is cold to let the cold in.

For sash ones, open top and bottom leaving the glass in the middle for
maximum convective flow. Their strong point being they don't stick out
into the street.

Oh, you probably need to turn your PC off too (500W continuous adds
up!). And worry about burglars.

Andy