Electric heating

[Jeff.B]

Hallo folks,

Very soon to be moving to Brittany (can't wait)!

Has anyone installed Redwell Infrared heating panels in their properties? They are made in Austria and look great; the blurb suggests they are fairly cheap to run, and easy to install.

I need to provide some secondary heating in our property - something you can just turn on and off as required - these look ideal.

It would be useful if someone has experience of using them before splashing out cash - here's a link to Redwell: http://www.redwellheating.com/

Many thanks

Jeff

[Nick Trollope]

Coupla points;

Alll modern electric rads are 100% efficient.

Infra-red heaters heat whatever is in front of them, not the air (like a conventional radiator), this may be you, or your sofa...

The illustration on their front page is an "illegal" installation (in France).

That apart, they look very nice but there are plenty of very pretty rads available in France.

[maude]

Havnt seen any-that are less than Uks finacial deficit. Maude

[UlsterRugby1999]

[quote user="maude"]Havnt seen any-that are less than Uks finacial deficit. Maude[/quote]

Sorry maude - just what do you mean [8-)] [8-)] [8-)]

[Jeff.B]

Thanks maude, that made me laugh!

Yes they are expensive to buy initially, I finally managed to get a price guide from the distributor - from around £400 for basic 350W, to £700-800 for 900W. The pretty picture ones cost more.

The point is how efficient they are at providing adequate warmth per unit of electricity. The factsheet from Redwell suggests very good efficiencies - comparable or better than mains gas, and I wondered if anyone had some personal experience of these infrared units that may confirm this.

Currently, the CH heasting in our house is from an oil boiler - ok if the house were fully insulated (I will be working on that) but we wanted to provide secondary provision for times the CH is not on, especially in the bathrooms. Trying to decide on the best mix of heating provision is not the easiest task in older properties, I'm sure many folk in France also want to know how to spend their cash in order to provide the best heating options for their buck in the long term.

Sorry, I've gone off on one here - I didn't mean to write a tome, but it is a complicated subject.

BFN

Jeff

[Nick Trollope]

Just to reiterate my earlier point, all (most) electric rads are 100% efficient - every Kw of energy you put in comes out as heat. A gas boiler is about 75% efficient (once you have taken all the losses in the system itself into account), a good woodburner is about 75% efficient, too.

At those prices, you would make significant inroads into the UK national debt. They are cheaper in France! (albeit not much).

 

[Owens88]

Some considerations:

The radiant heaters produce 'nice' heat for anything within line of sight of them ( a bit like coal fires. Does anybody else remembre the doctor visiting and standing with backside to fire?).

If you want a general 'air heat' you might need to supplement the radiants with a convector.

[Gardengirl]

One of our neighbours has had a heat pump installed instead of the heaters already installed in the apartments which seems very efficient. Inside it just looks like an ordinary heater; outside there's a box outside similar to those for air con systems. If we had outdoor space where one would fit comfortably without getting in the way we would have one of those installed. 

[La Guerriere]

Nick, you may be able to cast light. I know that NFC requires fixed heaters to be wired in rather than plug'n'socket but is there actually any logical technical reason for this .... ?

[Nick Trollope]

[quote user="La Guerriere"]Nick, you may be able to cast light. I know that NFC requires fixed heaters to be wired in rather than plug'n'socket but is there actually any logical technical reason for this .... ?[/quote]

A few, I'd guess; A class I heater would need 4 pins, a classII heater would require 3 (not including the earth); so you can't unplug them without switching off; because they must be on their own circuit and if you had a socket you could put an adaptor in it and run something else; etc etc....

 

[Jeff.B]

Thanks Nick,

I take your point - but Redwell are claiming that for every 600W electricity input, there is 1980W heat delivered. Is that just over 300% efficient?

You sound like you know about heating - do you have any advice/suggestions for what route to take to heat a 400 cubic metre stone house as cheaply as possible?

Cheers

Jeff

[La Guerriere]

Redwell may also do perpetual motion machines.

For the low cost solution, there is no total solution, but insulate like crazy and shop around for electrical radiators on promo. Bathroom electrical towel rails are usually on promo somewhere.

[DerekJ]

[quote user="Jeff.B"]Thanks Nick,

I take your point - but Redwell are claiming that for every 600W electricity input, there is 1980W heat delivered. Is that just over 300% efficient?[/quote]

No,that's not what they are claiming Jeff. They are claiming that the Redwell IHS 600 (600w) panel provides the

same amount of heat as a 1980 Watt (≈2Kw) electrical convection heater.

In other words you'd have to have a convection heater rated at 1980 watts to equal the heat output of their 600w heater.

You can't get out more than you put in.

[Owens88]

Even that is a dubious claim. I could understand a claim based on heat effect, as radiant gives comfort quicker, and more effectively on anything in line of sight, than any system that relies on heating air to eventually heat you.

[Poolguy]

[quote user="Jeff.B"]Thanks Nick, I take your point - but Redwell are claiming that for every 600W electricity input, there is 1980W heat delivered. Is that just over 300% efficient? You sound like you know about heating - do you have any advice/suggestions for what route to take to heat a 400 cubic metre stone house as cheaply as possible? Cheers Jeff[/quote]

Jeff

Is that ...'cheaply as possible'.... meaning, cheap to install, or cheap to operate your heating system???? 

Not really the same thing, Electric my very well be the cheapest to install but it isn't anywhere near the cheapest to operate - that place is comfortably occupied buy a combination of solar and wood chipburner. If you are into the thinking on the subject its plain to see that (especially with house the size of yours) that the running cost will dwarf the installation cost in a very short space of time.

So, as has already been suggested, insulate the hell out of every part of the house and then choose to either pay now and nothing for ever after or, pay less now and for ever more pay even more than you can ever imagine.

Andrew

 

 

[Jeff.B]

Hallo Derek - this is what they claim. Example:

Redwell IHS 600 panel, surface area: 100 x 60 cm = 6000 cm2.

6000 cm2 x 0.22 Watts = 1320 Watts equivalent heating

capacity on the front side of the heating panel.

The rear side of the panel produces approximately half as much

heat as the front side so: 1320 x 1.5 = 1980 Watts equivalent

heating output for the whole panel

Based on this calculation, the Redwell IHS 600 provides the

same amount of heat as a 1980 Watt (≈2Kw) electrical

convection heater.

An energy saving of nearly 70% = 1/3rd of the energy required.

They are making a comparison with the convection heater just so people can visualise the amount of heat-output. It is clear they do mean 600W provides 1980W of heat - i.e. they are over 300% efficient.

I originally asked if anyone had real experience with these panels for feedback on these claims.

I love this stuff - it's a very meaty subject!

[Chancer]

Publicité mensongeuse.

All electric heaters are close to 100% efficient but there is nothing on this planet outside of science fiction movies that is more than 100% efficient.

If there were inefficient electric heaters, which there arent, then they could claim that their ones were 3 times more efficient.

I was so enraged at the claims by Alterno for their storage heaters that I filled out the coupon for the soi disant technical expert to come and explain it to me.

After a long and at times heated discussion where it became apparent that he had no comprehension of the laws of thermodynamics he remained convinced that his heaters would reduce my electric bill by two thirds despite the fact that 2/3 of the time they would be consuming energy at heures pleines costing 55% more than my heures creuses consumption.

Mine was a serious enquiry as I need to buy heaters for 6 more apartments, he did his calcs based on the size of my existing apartment and came up with an annual electricity consumption figure compared against you guessed it, fan heaters making his look really efficient, then I showed him my electricity bills for the last 3 winter periods compared to my unheated summer ones, my cost of heating was 25% less than his calculations which I am sure are far less than the true consumption, he kept repeating that his heaters were so good they only consumed electricity 6 minutes of every hour!

Oh and the final nail in the coffin for what for him was a very tempting offer, the price E2393 TTC for a 1800 watt heater compared to the £120 + Vat that I paid in the UK [:-))]

[Jeff.B]

That's cheap to operate, Poolguy. You're dead right, I will certainly be looking to insulate as much as I can get squeezed into the place.

Do you have a woodchip burner? Combining solar thermal with the other heating systems seems a good idea - I'll also be looking into what financial assistance is available for energy conservation now.

Cheers

[Owens88]

[quote user="Jeff.B"]Hallo DerekI love this stuff - it's a very meaty subject![/quote]

Pardon me for not having measurements, and I understand your original request.

First off. If the Redwell b**** you quote is valid then convector heaters would win hands down, because they heat from a fin in the middle with greater surface area.

Second off. The radiants create a temperature effect which is not the same as raw heat. Therefore the back panel is radiating to the wall which is then becoming a convector.... I don't think the equations are equivalent in the way they claim. But how do we attract a physicist to this thread ?

I still believe what I said in an earlier post, you will want both but have the radiants pointed towards where you want comfort (seating positions etc.) and at least one convector providing an overall acceptable air temperature.

John

[nomoss]

[:D]

[DerekJ]

[quote user="Jeff.B"]

I love this stuff - it's a very meaty subject![/quote]

Hi Jeff. My old schoolboy physics isn't upto a detailed investigation into their claims but the expression that comes to mind is:

"Bullsh*t baffles brains"".

I'm still left with the basic belief that you can't get more heat energy out of these types of heater than you put in. 100%  efficiency is the best you can hope to achieve and the conventional wisdom is that electric heaters are 100% efficient in that sense. I don't understand the science that says it can be 300%  efficient.  As someone else posted previously... do they also make perpetual motion machines? [:)] 

[nomoss]

 

It seems P.T.Barnum’s immortal phrase still holds true.

[Pickles]

[quote user="Jeff.B"]Redwell are claiming that for every 600W electricity input, there is 1980W heat delivered. Is that just over 300% efficient?[/quote]

You don't need a physicist: you seem to be doing perfectly well without one. I can't find that claim on their website, but if it were stated in that way then unless it were a heat pump - which it isn't - then they would be claiming to create energy; which would be impossible.

Stripping away all the guff, what they are selling is a sheet of metal heated by a weedy element. It doesn't get that warm, hence although SOME of the heat IS used to heat the air by conduction to the air immediately in contact with the sheet and thence into the room by convection, the temperature difference between the air and the sheet is not that great, so heat transmission by this means is relatively low. Thus the sheet will radiate a good proportion of the energy into the room as infra-red - in this case long wavelength IR. The air in the room will not attenuate this very much at all, so this IR radiation does not heat up the air and can thus heat up any surface on which it impinges.

The comparison claim made above, as far as I can see, is that a standard convector heater will put rather more of its heat (as a proportion) into heating the air (.... that's what you wanted it to do), and so as a proportion, the amount of energy that it puts into the IR that it generates is lower than these low-temperature panels.

HOWEVER, bear in mind that you are comparing apples and oranges: from a comfort point of view, the two systems are not comparable: in the case of convection heaters, the air is warm: in the case of IR heaters, the air is cooler. Don't expect to be able to feel the IR in the way that you would from a high-temperature radiant heater (eg the old style three-bar electric heater): the heat output is a lot lower.

So, no magic, no perpetual motion machines, just less heat (= less energy), but primarily IR transmission with a bit of convection versus primarily convection with some IR.

Edited to add: I don't think that I would want to use these panels as a primary heating source ...

Regards

Pickles

[Jeff.B]

No, nor mine - and you're dead right, Derek, blinding people with science in order to sell a product is a bit disingenuous, and can put people off what may be a perfectly good product.

I suppoes the term 'efficient' is used loosley here, I think it's the conversion of electrical energy to 'heat' energy (what we want) that is being described. A heat pump certainly delivers more heat kWh's than the electricity kWh put in - this is the coefficent of performance (CoP) talked about with these systems. I know this is true because I've monitored an air-to-water heat pump for the last 14 months. Electrical energy is used to upgrade low temp air to a higher temp that then heats water. The refrigerant used determines the resulting performance.

I have no doubt that the complexity of the physics invloved in heat pumps has a negative effect for people looking to buy them - it's just hard to expliain in layman terms - but they are efficent. You will get 3-4 times more heat from these per unit of electricity, than you will from a 1kW bar electric fire.

Heat pumps were rubbished quite a bit at one time - easy to do with complex science - but they are becoming established in mainstream heating outlets now because of their proven record. I'd like to think these IR panels genuinely do perform as described since space heating consumes the largest amount of energy in most homes,so could save people money and help reduce carbon emissions.

Apparently, a 12 month study into the performance of these infrared panels is due to be released - should be interesting reading and I'll post a link when it's available.

[Chancer]

Infra red heaters are fine in a spray shop for drying the paint on one panel or perhaps drying plaster on one piece of a wall but for home comfort heating for me they are a no-no, they do however allow the sellers to make dubious efeciency claims which no doubt suck in the vulnerable.

There is one way in which you could in fact benefit from this soi disant efficiency,  you would need to stand naked in front of the heater wearing thick soled slippers (cos the floor will not get warm) and slowly turn around to expose your whole body to the heat.

The problem is that you would look like a doner kebab, which is actually the best application of this type of heater. [:D]

For my money you would be far better off using panneau rayonant heaters, they are very cheap to buy (dont beleive the claims that the electronic thermostat ones are more efficient) give out a comfortable heat comparable to a wet sytem radiator and are 100% efficient like all other electric heaters.