On Monday, 13 November 2017 16:24:56 UTC, John Rumm wrote:
On 13/11/2017 13:58, whisky-dave wrote:

All we need is a heating engineer that knows stuff, both theory and in practice
It was 12C @ 9am, now 16C @ 13:45.

This is with 5 of 2KW heaters and 2 of 1.5KW heaters.

So if yuo wanted the demp to be 16C before the 10am class how many heaters would we need in total. ?


It seems like working out the heat loss from first principles would be a
good start:

http://wiki.diyfaq.org.uk/index.php/Heat_loss

Once you have a feel for that, you know what power input you will need
to maintain a steady state at a desired temperature. You would then need
to size the heating to be able to exceed that by enough to lift it to a
working temperature in a reasonable time frame (and what that is will
depend a bit on how the place s built - you may be able to achieve it in
a few hours, or you might need to heat it continuously if it turns out
the answer is "days").

So how would yuo go about that ?
What are the things you need to know ?

Think about it and you'll realise the where the biggest error would be.