radiator covers

albalad

economiser wrote:

albalad. Lining the enclosure with foil will not improve the output. This foil is effective on a wall behind a radiator on an outside wall as it reduces the amount of radiant heat absorbed by the wall.
Hope this is helpful

well I'm glad i only put it on my outside walls then ! :rolleyes:

I do understand what you are saying though.

alanobrien

economiser wrote:

alanobrien. The 20% reduction I mentioned is not a loss. It is simply that by restricting the air flow around the radiator you reduce the amount of heat it can give out. It just means the heater is less "effective" not less "efficient". It may be that you have heard of people "turning up the heat" because of this. If they increase the water temperature flow from the boiler than this would increase the radiator temperature and go some way to reversing the reduction effect of the enclosure.
Hope this is helpful

I hear what your saying but its not entirely correct.
There is an efficiency loss, simply because you are restricting the output of the radiator by masking the thermal pathway with an insulator.

In other words you are reducing the heat transfer co-efficient. Hence people compensate by increasing the room temperature.

Not good for global warming, but i guess if people hate the look of rads that much and are happy with higher fuel bills then good luck to them.

economiser

alanobrien

Sorry to disagree, and at the risk of being pedantic, reducing the heat transfer coefficient will only result in less effectiveness not less efficiency. A radiator like any heat exchanger must always be 100% efficient. What goes in must come out. You will get less heat but you will only pay for less heat and will not contribute more to global warming.

alanobrien

economiser wrote:

alanobrien

Sorry to disagree, and at the risk of being pedantic, reducing the heat transfer coefficient will only result in less effectiveness not less efficiency. A radiator like any heat exchanger must always be 100% efficient. What goes in must come out. You will get less heat but you will only pay for less heat and will not contribute more to global warming.

Feel free to diagree, active discussion is after all the basis of democracy.

Heat exchangers are NEVER 100% efficient, there is a scaling factor to consider for all heat exchangers which reduces their efficiency.

I know this because i design industrial equipment and have to calculate heat transfer losses in seals for compressors and pumps. This is how i make my living.

Anyway that's enough from me on this thread, feel free to maintain any and all of your own opinions.

economiser

alabobrien

I don't think we are far from agreement. Of course the losses in industrial heat transfer equipment but with a heat emitter in the heated space the losses will all be into the space.

My point in saying the radiator was 100% efficient was simply to make the point that all the heat taken from the water by the radiator must end up in the room. Although with the radiator cover there will be less heat coming into the room there will be less taken from the water and therefore no cash loss - in fact there could be a saving of course but at the expense of a cooler room.

Its just a pity that so many heating systems in this country use such ugly, if relatively cheap, radiators. If better looking and quality equipment were fitted in the first place then there wouldn't be the desire to enclose them with, in my opinion of course, equally ugly covers.

I'll end there too - see you on another thread maybe.

latecomer

SPAM. reported.

nicolas_garratt

Two points to make.
First, rad covers can be made very imaginatively with grills that some people use for cars. Various meshes are available too. A little imagination can get quite a pretty result!
Second, rad covers keep some of the heat inside the enclosure. It is essential that if the rad is on an outside wall something better than foil is used, and some decent insulation will pay for itself in months. The amount of heat the wall would allow outside would be much higher than in an uncovered rad. Foil is good for radiated heat, but most heat a rad gives off is convected, which the rad covers keep inside. Get decent insulating or heat recirculating radiator panels to reduce inefficiency.

olias

Does it have to have a cover? Have you thought of swapping the rad for a different one?

Either a traditional old fashioned type or one of the modern designer ones depending on the style of your house. If you shop around, the prices of both styles have come down a lot in recent years.

Olias

roguex

I would like to get some covers not for asthetics but for safety as I have small children. Can anyone suggest safe efficient covers?

Thanks
Lisa

loracan1

I ended up getting one from Netto, reduced to £20, needed to trim some of the depth down because the hall is narrow. Wasn't concerned with heat retention - it's only the hallway. Looks fine..