DIYbanter - View Single Post - Putting a double glazed pane in an old frame

In article ,
(jacob) wrote:

Come to think - summer heat gain would be based on difference between
reasonable room temp say 65F and high summer air temp say 85F - 20deg
F difference.

I haven't a clue what your numbers mean but reasonable room temperature is
for me 21C and a high summer outside temp is 34C.

Not a lot compared to winter frost, say - 5F; heat loss
based on temp difference of 70 deg F. Hence DG contribution summer
saving less than a 3rd of winter saving on any particular day with
these temperatures. It would depend on the frequency of high/low temps
and the efficiency of cooling compared to heating. I'd guess cooling
less efficient than heating but I don't know.
Opening windows a cheaper and more pleasant option.

Opening windows isn't an option at all. It doesn't work. And it isn't
pleasant.