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Double Radiators Upstairs?

Postby nalaknip » Tue Jun 01, 2010 9:15 am

I was thinking about replacing my radiators downstairs and upstairs from single to double radiators. My friend who is pretty savvy DIY wise says you cannot have double radiators upstairs due to water and pressure issues. is this true? Any help i would be grateful for.....
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Postby plumbbob » Tue Jun 01, 2010 6:01 pm

nalaknip wrote:.......says you cannot have double radiators upstairs due to water and pressure issues. is this true?


However, before changing or adding radiators you need to consider four things.

Has the boiler sufficient capacity to supply the extra output?

Are the supply pipes to the radiator sufficient to carry the extra capacity? (Usually yes).

Are the existing rads being heated fully and evenly over their entire surface area?

Now the last point and this is the tricky one.

The existing size of the rad should have been calculated to supply the correct amount of heat to that area. Randomly altering the sizes could be a recipe for disaster as it may unbalance the whole system making some areas red hot and others stone cold. Interestingly, it might not make any difference at all. It could also result in rooms being heated too quickly causing peaks and troughs in the temperature balance.

Look at the projects section for choosing radiator size. Follow the link to calculate the proper radiator size and compare it to those you already have fitted.

It is not common to see double panel rads in bedrooms unless they are very large or poorly insulated.
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Postby htg engineer » Thu Jun 03, 2010 2:09 pm

If the system works now, and all radiators heat the spaces effectively, then if they need replacing go for the same size, or you could go smaller if your current ones are not convector radiators.

High efficiency boilers are most efficient with less water in the system, if you double up every radiator you're doubling the water content too which will take longer to heat.

Although many will disagree as alot of plumbers don't like 10mm pipe and prefer 15mm, but coated 10mm systems are more efficient - regarding water content and the fact all pipework is coated/insulated.

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