Radiator orientation

I have a tall 'designer' style radiator in my bathroom which has never worked satisfactorily. In investigating this I have found that the design which is a hollow tube at the top and bottom which are connected by 8 fins can never have worked as the tubes at top and bottom are straight thru' ie with the valves removed I can see straight through. Therefore the water passes through the bottom tube without circulating through the fins, hence the rad just gets a bit warm through conduction. Both top and bottom tubes are straight thru.

It would seem to me the bottom tube (this has the valves) should be blocked half way along so the water is forced up the left 4 fins and down the right 4 fins.

The supplier (a bathroom showroom) have said they'll need to talk to their tech guys but my question is : would a radiator normally have to have some sort of baffle or shield to force the flow of water around the rad ? It strikes me the rad is perfect for horizontal orientation but would cannot possibly work vertically.

Has anyone else heard of this ? I'm hopeful the supplier will come good but wanted to be a bit better informed in case of any 'discussions' with the supplier !

thanks

Reply to
paul_j_tomlinson
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It's called convection. The hot water rises to the top through the fins and the whole radiator gives off heat.

Have you tried bleeding it?

Have you tried balancing it?

Have you read the central heating FAQ at

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Reply to
manatbandq

Convection within the radiator should enable the heat to reach the top, unless I have misunderstood your description of the radiator.

Perhaps the rad is not full of water? Is it so tall that it is taller than your header tank? Has it been properly bled until water comes out the top?

Also, many "designer" radiators have pitiful heat outputs, being designed for looks rather than performance. Are you sure you aren't getting the full output?

Christian.

Reply to
Christian McArdle

How can convection occur if the water is flowing into the radiator and straight out the other end of the tube (300mm) - the water has nothing to make it flow the 1800mm up to the top and down again.

It has been bled, balanced, you name it !

The stated output is around 1kW so would expect it to get pretty hot - it has never got more than lukewarm I believe due to conduction from hot water passing through bottom tube.

Reply to
paul_j_tomlinson

It has convection. It works there is hot water at the bottom and cold water at the top. This situation is not sustainable and the hot water will rise and the cold water will sink. Almost all radiators work on this principle and a standard horizontal radiator has nothing to deflect water upwards.

Is the very bottom of the radiator very hot?

Christian.

Reply to
Christian McArdle

The bottom gets very hot - as the bottom tube is very short

Reply to
paul_j_tomlinson

Does the pump speed make a difference?

MBQ

Reply to
manatbandq

The pump is already on high setting. The system is fairly large, 13 rads I think. The bottom gets extremely hot so cant see its a problem with enough water getting to rad

Reply to
paul_j_tomlinson

Perhaps it is too fast and interferes with the convection. Try balancing the radiator right down.

Christian.

Reply to
Christian McArdle

That may be a contributory factor.

MBQ

Reply to
manatbandq

|The bottom gets very hot - as the bottom tube is very short

Reply to
Dave Fawthrop

The water in it is completely clear so dont think is blocked at all. The radiator is new as is most of the CH system

Reply to
paul_j_tomlinson

The message from paul_j snipped-for-privacy@yahoo.co.uk contains these words:

If you had managed to balance the radiator the output temperature would be 11 degrees C below the input temperature. If the hot water flows straight through with no reduction in temperature then it has not been balanced.

ISTM that if there is no reduction of temperature across the the radiator then you effectively have a temperature inversion within the radiator which would prevent normal convection. The solution (assuming the radiator problem is capable of resolution) is, as others have already said, throttle down the flow through the radiator until convection circulation does start. 300 mm seems very short to me but would a manufacturer actually make and sell a radiator that wouldn't work properly under any circumstances?

Reply to
Roger

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