Infrared Heating Panels....Again!

Cardew

fishybusiness wrote: »

I know that very well. The point I am trying to make is that it appears that after an incredible amount of reading, to put it in simple terms.....

The electrical power required to heat a volumetric area is about 45 W per m3 for conventional space heating, and about 25 W per m3 for infrared heating.

If, and only if that is true then there is some truth in ability of infrared to lower electricity bills.

When I think of the cost of installing a wood burner, which in a lot of cases only actually warms one room, and wood isn't exactly cheap any more, I would happily use infrared panels at their reduced cost if they do actually do what they claim.

No one has come up with a technical reason why they should or shouldn't work, and that is what I am trying to get to grips with

Of course we can come up with a technical reason - by quoting the law of physics.

That someone has stated(to use your terminology) 'infrared is sized up at 25w per m3 of space' instead of 45w/m3 means exactly what?

If I 'sized up' a room at, say, 2w per m3 would that be acceptable? The same proof that 2w is a nonsense applies to your contention that 25w is the correct figure.

If you make a silly claim, then it is up to you to prove that claim! not get someone to disprove a claim.

Why not get and post information from the Energy Saving Trust or WHICH etc.

However if 'your;)' infrared panels are so wonderful, why not get infrared panels at a fraction of the price?

P.S.
As so often happens on MSE, I suspect that you have a vested interest in selling; Redwell heaters in this case.

penrhyn

Will no-one think of the remote controls?:rotfl:

fishybusiness

As so often happens on MSE, I suspect that you have a vested interest in selling; Redwell heaters in this case.

Oh dear, here we go.....you know, I am a cynic myself, which is why I came here for some interesting, perhaps knowledgable debate about Infrared. The other threads written by people asking are answered in a rather closed uninformed way. I thought it worthwhile to open it out, for my own benefit and maybe for others too.

If you must know, I am 44 yrs old, ex aerospace structural test engineer, ex IT company boss and just finishing my second year of a psychology degree. I'm no salesman, but I do have some skills, and a good bit of knowledge, but I am far from a heating expert...

The quoted wattages are what I have found out the companies are using a sizing guide, plus for space heating what the standards suggest, nothing more and nothing less. It did help inform me as to how the Infrared companies manage to quote their efficiency levels, and I thought it worth posting.

I asked about remote controls....:rotfl:

The reply I have received has 10 attachments of blurb, when I have read them, I'll post any useful or otherwise info

jalexa

fishybusiness wrote: »

...just finishing my second year of a psychology degree...

Ah, you are beginning to make sense...:)

grahamc2003

fishybusiness wrote: »

If you must know, I am 44 yrs old, ex aerospace structural test engineer, ex IT company boss and just finishing my second year of a psychology degree. I'm no salesman, but I do have some skills, and a good bit of knowledge, but I am far from a heating expert...

I think it's more a case of you don't like the (correct) answers given so far, rather than anyone having a closed mind.

One thing is absolutely certain, you wouldn't have the uncertainties you have if you have an engineering degree, as your mini CV implies but doesn't explicitly state.

The point is you'll get the same heat out of any (resistive) electric heater for the same cost. Depending on how that heat is delivered (i.e. the ratio between conductive, convective or radiative) there may be a subjective advantage favouring a particular ratio, or an advantage to heat or not heat the air directly, or a subjective advantage/disadvantage of supplying a visible glow with the heat. Under normal circumstances, when heating your house, the amount of heat is by far the dominating factor and the delivery of that heat completely unimportant for the physics. i.e. if you houise loses heat at 2kW at 0C ambient, then you have to supply 2kW (by any means) to maintain the temperature. You don't seriously think you can supply 1.8kW by radiative panels and maintain the temperature do you?

A while ago I bought one of those halogen heaters, wth 3x400W heating elements, cost about £12. That's a radiative heat, and I find it excellent for warming cold spots requiring a small amount of additional heating. It can deliver 400W, 800W or 1200W, so is flexible and can absorb varying amounts of power from my solar panels. It's light and portable - radiative, but completely different to an expensive fixed radiative panel (which I can't see as the best solution for anyone's requirements).

Cardew

Whilst simplistic, I still believe the best analogy is to compare Infrared heaters with lighting.

If I sit in a large dark room I can read perfectly well with a 30w desk reading lamp; the lamp is not much use to any other occupants of the room. Indeed I recall as a child reading with a torch(2w?) under the blankets after parents had decreed lights were off.

As said earlier, infrared heating has its uses in that it can 'beam' heat rather like the reading lamp/torch.

As for the Redwell heaters. Why would a German firm commission a technical report from Greece?

Have you read the report? It is full of irrelevant graphs and information; and the conclusion is just a joke for an engineering report. Why would Redwell heaters have any advantage over other infrared heaters. Did they test similar heaters?

jalexa

Just noticed something in the spec. Surface temperature is 95deg C but they are shown "unguarded", even the portable one.

Is that safe?

fishybusiness

One thing is absolutely certain, you wouldn't have the uncertainties you have if you have an engineering degree, as your mini CV implies but doesn't explicitly state.

Indeed, I have lowly HNC qualifications

I think it's more a case of you don't like the (correct) answers given so far, rather than anyone having a closed mind.

Are there any correct answers? The whole game of heating seems fully of compromise, and interpretation. Look around at the heat loss calculators, and radiator size calculators, add 10% for this, 5% for that, 5% for air volume movement.....

For my specific application, heat loss calcs show anywhere between 1200W and 1900W depending on who's calculator I use.

Perhaps it is more about best practice, for any heating system, and I am interested in the whole best practice for infrared, obviously I am probably the only one.

Anyway, I received a reply from a so called infra red heating seller, the technical part is just waffle, so here it is...

The first question he refers to btw was about interference with TV remotes

Thank you for your email and interest in Redwell Infrared Heating.

Your question is very valid but in brief answer, no, there are many different types of wavelengths of infrared. Please see attached data sheet which explains a bit more.
The infrared produced by a Redwell panel is called FAR infrared, this is the same wavelength as the infrared produced by our own bodies and the sun (the heat not UV light). This is why it's very natural for us and sympathetic to properties.

I have to say (I shouldn't really), I totally agree with you, convectors heaters use a lot of energy for their output and are unreliable. The reason this is, before a convector actually produces heat it uses energy, so before you feel any benefit you have used energy. Also heating something puts stress on that heater and over time the resistance will eventually break the item. With a Redwell panel the elements have next no resistance so all the energy which goes in is then released, so it is as near as you can get to being 100% energy efficient. This is part of the reason why you need less energy to heat a room but also heating the thermal mass requires less energy plus it retains the heat longer than air so then get reduced running times. Please see attached further information. This also includes a sheet on different types of infrared heaters. There are a few Eastern European or Chinese panels which are not tested and built completely different to Redwell. This removes any confusion.

penrhyn

There is a very good series on BBC about how electricity actually works.
Might be an idea if Redbad watches it.

http://www.bbc.co.uk/programmes/p00kjq6h


A study of Ohms law would not go amiss.

jeffwood

Hello all, i have been reading your posts and i would like to pass some more information to you.

First of all infrared heaters do not interfere with the rest of the wireless or cordless devices. At least not with mine :P Simply because they operate in different "frequencies".

I have two Welltherm heaters one in the leaving room and one in my bedroom. What makes them more efficient? Is that they convert into heat almost 90% of the energy that they consume. And this is the tricky part. There is not even one heater that actually can convert into heat 100% of the energy that it consumes. So the best products are the ones that are closer to 100%. Most of the infrared panels in the market convert 80 - 90% from European manufactures. At least this is what they claim. Cheap panels from the asian market may be good but not as good the European ones. And that is for sure. a friend of mine got a very cheap infrared panel and it just another object in the room. Definitely is not a heater.

So we covered the efficient part, lets see why they are more effective than the rest of the electric heaters. Firstly because we can heat areas with one panel, where before we needed 2 heaters. My leaving room is 5m x 4m x 2.4m and i use a Welltherm panel of 780W output. Before i had 2 radiators. That makes it more effective and more economical the same time. You feel the heat faster because it heats you directly and not the air. Similar with what the sun does. So if you have a heater that heats the air and you open your window then all of the heat will gone. This is not the case of infrared heaters. You adsorb the heat that the panels generate and then you reflect it back in the room. This is how the room gets heated. Even if you open the window you will be able to feel the heat from the panels.

To be honest i am very satisfied with what those panels have to offer. For sure are expensive to buy them, but you have a good return of investment.