Open plan and radiator sizing

7 Dec 2006
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United Kingdom
What is the best way to determine radiator sizes in an open plan kitchen / dining room / lounge, Would you calculate btu's on the total volume of the whole area, or treat it as smaller areas with imaginary walls.
Kitchen area is going to be difficult to find much room for rads, but we are concerned about creating cooler areas (if that makes sense ) Dining room is quite small and again limited with wall space, only option being a long low rad under a window seat, this then leads into a large lounge area.

Any advice appreciated
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You say that you are "concerned about creating cooler areas". I assume you mean that you do not want to create them.

Assuming you want the same temperature throughout, you can calculate the total kW required based on the total room dimensions. If you then insert imaginary walls and use the same temperature either side of the wall, you can calculate the requirement for each area. This gives you the information as to how the total kW should be divided between the areas.

Larger areas should have their individual requirement spread among more than one rad. Obviously with no walls between areas there will be heat transfer between areas., so the more evenly the emitters are spaced the better. A 3kW rad at one end to heat the lounge and a 1kW the other end to heat the dining room is not a good idea.
A good solution to heating a kitchen is to use fanned plinth heaters!

But a few people dont listen to the radio or make any noise and whilst they accept the sound of a boiling kettle they dont like the background noise of a fan heater.

Most householders dont see rads as anything other than a nuisence. To get good even results you need wide heat emitters and not the smallest double panel which will provide the same heat output.

When i say concerned about cold spots, i mean we don't want the kitchen area to feel cold due to lack of rads

I can see the logic of wide heat emitters, but with such a large open plan area, there is a lack of usable wall space, or rads will end up behind furniture

Is it still common practice to site rads under windows

We have considered plinth heaters for the kitchen (need to check on outputs)

This isn't my house by the way but i'm helping a freind renovate /modernise a detached house, while my work is quiet

Thanks for help
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We have briefly considered underfloor heating, but thought it would involve digging up all the exsisting floors in the original part of the house.

Is it considered a good option nowadays, how does it compare in price over conventional rads
UFH is not chosen on a cost basis.

There are very few situations where I would recommend UFH but in the right application it does give very comfortable and even heating and is very efficient with condensing boilers.

Conventional rads are cheap and give rapid heat up.

Its less importany in a well insulated property to have them under windows but that still often is the best visually.


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