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- 18 Jan 2014
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Morning All,
Tearing my hair out here doing rad calcs and all the online methods come up different. Surely someone's gonna get a prize for being the millionth person to ask this soon. Anyway, I've got all super nerdy and used the Kermi calculator and I've measured all the windows, correctly entered the walls types and thicknesses, same for the floors and ceilings, adjusted each room temperature according to the wishes (orders) of my missus. With this info the software accounts for heatloss/gain from adjoining rooms, and I've allowed for an outside design temp of -3 instead of -1. And I've added 10 percent for fast heat up.
So my question is - Because of the high level of detail involved is it more reliable than the simple calcs and "rule of thumb" methods? The temptation is to go large on the rads firstly cos if I mess this up the aforementioned missus will make me suffer and secondly cos there are some great package deals out there which are better value if you pick big rads.
I'll be fitting TRVs to all rads and using a room stat so does that mean it doesn't matter and get the biggest rad that looks right for the room as the TRV will manage it?
Loads of people say that big rads mean the return temp to boiler is cooler and the boiler is then more efficient, but surely modern combis with electronic wizardry inside can deal with higher return temps!
For info - there is no chs in the house, just a gas heater for the taps. And I will be using a RGI for the boiler install - I'm not even going to take it out of the box! it's a 1939 house, solid walls, semi detached, with cold roof space, bare timber floors on joists
I'd really really appreciate some wise words on this asap -I need to get a crack on with the chs or I'll be in the doghouse (which is also unheated!).
Cheers in advance,
Pete
Tearing my hair out here doing rad calcs and all the online methods come up different. Surely someone's gonna get a prize for being the millionth person to ask this soon. Anyway, I've got all super nerdy and used the Kermi calculator and I've measured all the windows, correctly entered the walls types and thicknesses, same for the floors and ceilings, adjusted each room temperature according to the wishes (orders) of my missus. With this info the software accounts for heatloss/gain from adjoining rooms, and I've allowed for an outside design temp of -3 instead of -1. And I've added 10 percent for fast heat up.
So my question is - Because of the high level of detail involved is it more reliable than the simple calcs and "rule of thumb" methods? The temptation is to go large on the rads firstly cos if I mess this up the aforementioned missus will make me suffer and secondly cos there are some great package deals out there which are better value if you pick big rads.
I'll be fitting TRVs to all rads and using a room stat so does that mean it doesn't matter and get the biggest rad that looks right for the room as the TRV will manage it?
Loads of people say that big rads mean the return temp to boiler is cooler and the boiler is then more efficient, but surely modern combis with electronic wizardry inside can deal with higher return temps!
For info - there is no chs in the house, just a gas heater for the taps. And I will be using a RGI for the boiler install - I'm not even going to take it out of the box! it's a 1939 house, solid walls, semi detached, with cold roof space, bare timber floors on joists
I'd really really appreciate some wise words on this asap -I need to get a crack on with the chs or I'll be in the doghouse (which is also unheated!).
Cheers in advance,
Pete