halogen heater query

Cardew

RobbieJ wrote: »

Correct, but there is a whole electromagnetic spectrum of energy.

Sorry but that is bluster!

You should know(now) your earlier post is completely incorrect.

RobbieJ

Cardew wrote: »

Sorry but that is bluster!

That doesn't answer the point made but, instead, postures a bit like a Catherine Tate "whatever"...

An electric fan heater will use electricity to drive the fan, so that means less for the heating element - obvious really - other heaters do not have that overhead.

Your original assertion is a good approximation, but strictly incorrect. However, there is no point in talking to a person who doesn't want to listen.

Cardew

RobbieJ wrote: »

That doesn't answer the point made but, instead, postures a bit like a Catherine Tate "whatever"...

An electric fan heater will use electricity to drive the fan, so that means less for the heating element - obvious really - other heaters do not have that overhead.

Your original assertion is a good approximation, but strictly incorrect. However, there is no point in talking to a person who doesn't want to listen.

So you have re-invented physics with your assertion of an overhead!

You are absolutely incorrect!

A 1kW fan heater with a fan using, say, 20 watts and 980watts for the heating element will consume 1kW and produce exactly the same amount of heat as any other 1kW heater.

What happens to the energy used to rotate the fan? Some will be used to overcome the friction in the bearings (generating heat here), and some will be used to move air, and when the air slows down due to its viscosity, the energy again gets turned into heat which warms the air. Add it all up, and you'll find the amount of heat created by a heater exactly matches the energy input into it. (That applies not only to heaters, but all electrical devices - they all produce heat equal to the energy consumed, but hopefully do something useful before the heat release).

I really wish you wouldn't come on MSE and post something totally incorrect and then feel you have to defend that nonsense.

I ask again, bearing in mind you cannot detroy energy, where according to your theory of an overhead has that energy to turn the fan gone, if not heat?

RobbieJ

Cardew, you may understanding the principle, but, to be precise, you misunderstand or cannot comprehend the practical issues that necessary follow on from the principle.

Energy is conserved i.e. it cannot be destroyed, but energy only has a heat equivalent, it can and does exist in many different forms. Therefore, the electricity used by any heater has a heat equivalent, but different electrical heaters have different electromagnetic spectrum output profiles. You seem unable to grasp this practical consideration and conveniently avoid to answer this point.

If a heater generates light as well as heat, then the energy output is identical to one that consumes the same amount of electricity, but only generates heat - but their output energy spectrum profiles will be different.

The second will however, in everyday practical terms, be more efficient at heating a room. The first uses some of its electrical energy input to generate light, some of which will leave the room via the windows. Certainly, a very, very, very small percentage of energy will leave the room in this form before it converts to heat, but nevertheless, that very, very, very small percentage does exist.

HappyMJ's "the light you see hits a surface and then the light energy converts into heat" will occur outside the room, thus the design of the heater makes it less efficient at heating the room - even given the fact that energy is conserved.

An electrical fan heater will similarly conserve energy, but the output energy will have a different output profile to a heater that does not incorporate a fan.

As I originally said, your statement is a good approximation, indeed it may be a very good approximation, but strictly speaking (when talking about the efficiency of heaters to heat a room) it is incorrect.

Before quoting from lay posters elsewhere without giving attribution (which may be a breach of copyright if your quote eminates from a source external to this website), just think for a moment on how the different electromagnetic profiles of different heaters effects their ability to heat a room. Unfortunately, a grasp of the laws of physics does not necessarily give you a grasp of practical issues in the everyday world about us as you appear to believe.

If you want the last word, then sure post ahead - with insults and insinuations if you feel so incline. However, this really is my last word on the topic as there is no point in becoming part of a protracted slanging match which, given you past posting record here, you seem to delight in.

Oh, and before you start posting snippets in bold type, such as in this example, note: The educated mind can be persuaded by logic, the uneducated mind gravitates towards volume.

Cardew

More bluster!

Fargo

This is all very interesting to those who progressed further than O level physics but for us lesser mortals who are interested in the pros and cons of halogen heaters possibly not. I live in an old, cavity wall free, single glazed house and think it may be cheaper to use a halogen heater, for instance when sitting in front of a computer, than putting the gas central heating on. There are too many radiators to fiddle about turning them all on and off all the time so some are on all the time. What do those with more knowledge than myself think. Ps the light generated is irrelevant, I have a lamp.

Cardew

Fargo wrote: »

This is all very interesting to those who progressed further than O level physics but for us lesser mortals who are interested in the pros and cons of halogen heaters possibly not. I live in an old, cavity wall free, single glazed house and think it may be cheaper to use a halogen heater, for instance when sitting in front of a computer, than putting the gas central heating on. There are too many radiators to fiddle about turning them all on and off all the time so some are on all the time. What do those with more knowledge than myself think. Ps the light generated is irrelevant, I have a lamp.

Welcome to the forum.

It would be more convenient using any form of electrical heater for the situation you describe, rather than putting on the CH and having to turn off radiators.

If you don't want to switch off the radiators round the house, then an electrical heater would be cheaper. I have a fan heater in my study for just that purpose; the CH goes off at 10pm and I can switch the fan heater on after that if needed.

In fact a halogen heater would be better than a fan heater in that it 'beams' heat toward someone sitting at a computer and there is no need to warm the whole room.

The point we have been making is that all electrical heaters give out exactly the same amount of heat, for the same running cost.

luv_my_brass

Fargo wrote: »

This is all very interesting to those who progressed further than O level physics but for us lesser mortals who are interested in the pros and cons of halogen heaters possibly not. I live in an old, cavity wall free, single glazed house and think it may be cheaper to use a halogen heater, for instance when sitting in front of a computer, than putting the gas central heating on. There are too many radiators to fiddle about turning them all on and off all the time so some are on all the time. What do those with more knowledge than myself think. Ps the light generated is irrelevant, I have a lamp.

I have been reading this discussion with interest because this (BiB) is my situation and looking for direct heat, also my GCH radiatiors don't seem to give enough heat around the house until it's almost bed time I get out my trusty old SuperSer (bought it 2nd hand 25 years ago) in the cold months for additional/direct heat, but thinking about replacing it with a newer model. I also have a halogen heater in the loft, which was banished there when I suspected that it was expensive to run.
After reading this thread, and weighing up the heating costs, it would appear that calor gas is the most expensive to run. So I am now feeling reluctant to spend money on a newer model. Would I be better off getting out the oscillating halogen heater out of the loft and getting rid of the SuperSer altogether. The heater and 2 gas bottles do take up a lot of space when not required. But then again, if there was an electricity cut, it would prove very useful - decisions, decisions

slim25

Hello all.
I was reading this as I am looking into heating my garage/ workshop.
Is it cheaper to use a gas heater 4.2KW( the portable butane canister type at £33 for 15kg) or an electric halogen heater 1200W from my mains.
From what I read a butane gas heater would be better but if possible could someone with a greater knowledge let me know.
Thank you
Ps Ive noticed that they do a 3KW halogen heater for around £200.
I presume the 4.2KW gas heater gives out 3.5 times more heat that the 1200w halogen so would i need to get a 3-4 kw halogen to give out the same amount of heat or does it not work like that????

jonsox

Hello,
New to the forum and have read the discussions on heaters with interest. I do have to say at the outset that I do agree with Robbie's statement that because a heater ( or any other electrical appliance) is labelled, say, 1 KW it does mean that it consumes 1KW of electricity but does NOT mean that it uses all of this energy to, in the case of a heater, produce heat or in the case of a light bulb to produce light. Ever tried to change a light bulb ( tungsten element type ) before it has cooled down!
Ergo different types of heater will use the energy in different ways and will not convert all of the energy into heat, some will do it better than others but none will be 100% efficient.
One only has to take the example of LED lamps where a 4 watt LED lamp will produce as much light as a 50watt tungsten lamp and produce very little heat i.e. most of the energy is converted into light. whereas in a tungsten lamp an awful lot is wasted in heat.
Thus a halogen heater, conversely, must waste some of the energy as light. and a fan heater will use some to drive the fan motor.
So if you want maximum heat a black radiant element is more efficient in producing heat than one that lights the room up, and if light is required then a cool LED lamp will be far more efficient than a tungsten or halogen lamp which both get very hot.
Hope that helps?
jonsox