Heat loss calculations

[PH951]

Up to now I have been happy using online heat loss calculations for sizing rads, But I have been asked to quote for a 300 year old farm house. (Complete new system) The house is 200m2 with stone floors and all external walls are between 500mm and 1000m thick stone with rubble infill. I can't find any calculators with options for stone floors and walls of this build. I think it will be a case of working out btu's by using the worst settings on the heat loss calc then adding something like 40% to each room.

Maybe time to buy a mears calculator.

If anyone has any advice I would be very interested to here.

 

[fuzzy]

you could use the whole house method to give you an idea of what is required for the full property, other than that i would do it long hand

 

[PH951]

Well I better get it right because only the bedrooms are getting TRV's And it will be powered by a heat pump so each rad will need to be 30% bigger than the heat loss calcs results.

 

[CharterGAS]

use the calculator for m the heating and hot water information council
its in depth and very accurate

Those on line calculators are rubbish

 

[PH951]

Thanks chaterGAS, is this the one?
[DLMURL="http://www.centralheating.co.uk/index/fuseaction/site.articleDetail/con_id/5525"]About HHIC's Heat Loss Calculator - Heating and Hotwater Industry Council (HHIC)[/DLMURL]

 

[CharterGAS]

yes it is!

 

[fuzzy]

Well I better get it right because only the bedrooms are getting TRV's And it will be powered by a heat pump so each rad will need to be 30% bigger than the heat loss calcs results.

why do they need to be 30% bigger?

are u thinking of the running temps being lower? dont worry, the rad outputs have been corrected to suit lower flow/return temps. anyway, 95% of the time a rad will be way way oversized anyway