Radiator Covers!

[gg]

Hi

My wife has a hate for 'bare' radiators - main reason being....they are ugly...and we are not in a position to replace...

I have no doubt that the covers are restricting heat etc

But....

Seeing as I have to keep them, could I increase heat by doing the folllwing?

1) As the top of the cabinet is MFD (it all is) - it forms a 'shelf' over the radiator, what if I get my 'jig' out and actualy cut slits or even take a large secton out of the middle (and perhaps replaace with a gauze etc?) - this would then (in theory) allow heat to rise from the rad...but still allow rad to be cased?

Am I talking nonsense or would it work?

[Andy Hall]

Tell her no. We all know that radiator covers are plug ugly and capture all kinds of dust, fluff and crap inside.

Radiator covers do have slots in the bottoms, grilles, etc. etc. but reduction in heat output is still up to 30%.

[Mary Fisher]

How much time does she spend looking at them?

Mary

[Guy King]

The message from [e-mail] contains these words:

That's OK, I can't stand radiator covers. Horrid pretentious things.

Anyway, if you want to lower the thermal resistance of them, then anything that improves the airflow should help. Slots, yes, that'd help, even silly things like rounding the lips/edges of the insides of the holes to make it easier for the air to slide out will help.

You could try using a spare PC fan to encourge the air along - they're very quiet if you run them slow enough.

[The Medway Handyman]

Hmmmm! Was it Oscar Wilde or Einstien who said that energy cannot be created or destroyed?

That heat has to go somewhere. Maybe its absorbed by the MDF but since it causes no physical change to it perhaps the MDF acts as a heat store?

But 30% cannot simply disappear.

[Frank Erskine]

No - it just goes back to the boiler from whence it came. The radiator is simply lagged by the air trapped in the naff cover.

[Andy Hall]

It doesn't.

Remember that the main mechanism for radiators to release heat is convection.

Think of a radiator with no fins and one with. The fins increase surface area and effectiveness of convection. Effective convection also requires that air can flow freely over the hot surface. If that flow is restricted, the amount of heat that is transferred to the air is reduced.

The effect of the reduced transfer of heat is that there will be less given up from the water flowing through the radiator. If the water flow rate remains constant, it implies a lower temperature drop. If the flow temperature into the radiator is fixed, the return temperature will be higher than it would otherwise. Either the boiler thermostat will turn the boiler off sooner or a modulating boiler will reduce output.

So no disappearing tricks, no hankies in private parts, and no rabbits in hats.

You must admit that this would be a bit difficult to stage.....

[Steve Firth]

No.

[<me9]

It never gets there in the first place. You need much bigger radiators with covers, and a much bigger cover, much uglier than the original radiator.

Some people just have too much disposable income, but it's handy for those in service industries. 8_)

[<me9]

Might as well get a fan convector then, much smaller and leess conspicuous.

I'm thinking of hiding the radiators under the floor. Has anyone any experience of installing UFH in an extant suspended timber floor without removing all the boards?

[Guy King]

The message from "The Medway Handyman" contains these words:

The water simply leaves the radiator hotter than it would without the cover. This means that the room takes longer to warm up - to get a similar output to a naked radiator the output temperature will have to be quite a bit higher.

This may not matter, provided the radiator can cope with the room when it's covered, but if any were marginal before you'll really notice it.

If the boiler output sensor cuts in, as it probably will then the duty cycle of the boiler will be lower so the overall heat input to the house will be lower.

[Guy King]

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You could probably have a trench heater, provided it ran the same way as the joists.