In uk.d-i-y raden wrote:
In message , Eric Sears
writes
Of course, if the panels were for space heating, you might want the
greatest input in the morning, in which case the east facing roof
might be better. There are a number of factors to consider.

Like ...

what time the sun rises in winter, how big a thermal store you would
need to store sufficient heat overnight

it's just not very realistic for heating

Well...

I think the usual assumption is that the building will have significant
thermal mass internally, in the form of an insulated concrete slab, or
something.