Heating My Home With Friction

davewho,

Do you have free electric? If not, you are going to spend more on electricity than on heating fuel. Why do you want to use friction heat?

Mike

I'm sorry, But I just don't see any advantage to heating with friction... You need energy to make friction, and you loose most of it trying to convert that energy to heat through mechanical friction. Please explain your motive for friction heat, maybe you are in a special circumstance which i cannot fathom.

Using friction to to heat - has a couple of very obvious useful benefits.

Friction is universally available all the time.

There is no scarcity of it nor will there ever be a scarcity of it.

Heat is the most easily achieved of all of the mechanical energy conversions which man can attempt - so this is also a plus.

Please elaborate on the actual capture of all those heat energies you're talking about!

"Friction is universally available all the time."

Further to other replies, please elaborate on your proposed energy source. And please don't give me the fiction that it's friction itself (which you seem to suggest).

_{Dag nab it - let's go dig us a Friction mine! We'll all be rich!}

"Why do you want to use friction heat?"

A traditional practice in the Alaskan Interior is to briskly rub one's hands together upon coming in from the cold. Perhaps the OP wishes to adapt this technique to home heating in general?

I know that type of heating method!! When you get inside firmly clap your hands together and then followed by rubbing them- as you said - until they get warm or you've had enough of rubbing.

Another way, I saw in bug's bunny, to get a woman for yourself to keep you warm and you can rub as much as you like.

No Geothermal vents in Alaska?

Put a faucet on the oil pipeline is more cheaper i think

You could spin a paddle wheel inside a liquid, converting the mechanical energy into heat. This method has the advantage of being relatively quite and having no wearing surfaces.

The original Mr Joule did this sort of thing.

You wont get something from nothing though, (1kW of electrical energy) will turn into (950W of mechanical energy + 50W of heat) will be converted to (940W of heat + 10W of noise).

He can bypass all that mechanical mess and simply plug in an electric heater. They're 100% efficient at converting electricity into heat and are available at the local hardware store about eight hundred miles away.

I remember from thermo class (many years ago) that ohmic heating (like all plug in hot wire heaters I've ever seen) is very inefficient. If I get the time later I'll do some study of this. I suspect the manufacturers do not present their efficiencies correctly.

If it's inefficient as a method of producing heat, where is the lost energy going?

I think it is lost as heat!!!!!!!!!!

You probably mean it is not cost effective.

Good question. Some time ago I compared the the amount of BTU that comes out of a natural gas furnace to a hot wire furnace (from manufacturers info) based on the joules of energy in (electricity in one case and chemical energy in the other).

For the same amount of energy in, the gas furnace produced much more BTU.

I by no means say this is a a solid conclusion because this obviously is not "efficiency". I hope someone who deals with energy conversion and heat transfer regularly will comment on the efficiency of ohmic heating. Maybe you already have. But I do remember my thermo Prof saying how inefficient ohmic heating is at converting electrical energy to heat energy. Maybe I dreamed it.

May be a communication gap.

Most likely your Prof has said that electric heating is inefficient (the others you might have extrapolated ?)

A good electric heater will be almost 100% efficient (only a tiny portion is radiated as light energy).

The problem is the electricity is coming from an in efficient conversion + transportation

If you burn the coal/gas/oil instead of using the heater , the same amount of fuel required to deliver say 2KW to your heater will generate more than 2KW of heat.

Because in your each KW recd you add the losses through flue gas, conversion efficiency, transportation, pilferage (looks it is there world over as per another active link) and that is the heat generated by the fuel.

Another thing I thought was true is that "heat pumps" are more efficient than ohmic heating. If ohmic heating is almost 100% than heat pumps must be less efficient than ohmic heating.

So we are on the same plane, heat pumps and hot wire devices start with electrical energy and end with heat energy. I am not talking about what takes place outside of these devices.

I am in mild disagreement with a couple posters here but I appreciate that we can have this discussion in a reasonable manner.

Heat pumps are basically fridges.

Modern ones are simple and very effective. Even the heat from the motor is collected and used!

I think any comparison with the effectiveness of Ohmic heating is so far from reality as to be completely laughable!!!

Chalk and cheese.....?

Hot wire heaters (ohmic heating) and heat pumps both take a given amount of electrical energy and convert it to heat energy. A comparison of these two types of heating methods from electrical energy seems appropriate so we can make good decisions as to what methods we would use to make the most heat with the least electrical energy.

If heat pumps are truly better than hot wire devices than it stands to reason that hot wire devices are not "almost 100%".

"hot wire devices are not "almost 100%"."

AAAARRRRRGGGGGHHHHH!!!!. Your just not getting it! Hot wire devices, are in fact, almost 100% efficient. You seem to be confusing efficiency with cost of operation. Electricity, although efficient, is an expensive way to heat. The sole reason for this is the price of electricity.

Thank you for the good explanation that corrected my thinking without the personal jabs. Personal jabs have no place in an honest technical discussion.

I rated your comment a GA!

"However, from a given amount of electrical energy, you can get more heat from a heat pump. It isn't that the heat pump is "more efficient" at making heat. The heat pump, for the most part, does not make heat; it moves it from one place to another, like a refrigerator."

Does 'more heat' and "more efficient" factor-in the waste heat energy dissipated into the atmosphere by the pump itself? You've got the fan and the compressor both located outside and so any heat they generate never makes it into the house. Ever.

I rather suspect that, at least in terms of heating, a heat-pump is an inferior solution as compared to the efficiency of ohmic heating; that is, 100%.

Modern heat pumps also harvest the heat they themselves generate......they are pretty efficient when used in a correct manner.

Though it is best (in any system) when the heat is basically free.

A friend of mine put a huge coil of underfloor heating tube just under the grass in his lawn to feed a heat pump. It works all the year round except when snow is on the ground......he saves a mint!!!

A heat pump takes a high volume of low quality heat (warm water or air for example) and turns it into a lower volume of much higher temperature that can be used to heat water in a heating system.

The energy input is only a relatively small motor and in good units, even the motor is cooled to gather that heat too.

Have a read here:-

http://en.wikipedia.org/wiki/Heat_pump

You will find a sentence in this article that reads like this and shows that a heat pump can make upto 3 or 4 x heat than can be generated Ohmically from the same amount of electrical energy:-

When used for heating a building on a mild day, a typical air-source heat pump has a COP of 3 - 4, whereas a typical electric resistance heater has a COP of 1.0. That is, one joule of electrical energy will cause a resistance heater to produce one joule of useful heat, while under ideal conditions, one joule of electrical energy can cause a heat pump to move much more than one joule of heat from a cooler place to a warmer place.

I hope that this clears up your missunderstandings in this area......

I read your comment before you edited some things out of it. Yes I am a degreed engineer from a well known State School in the USA.

I was mistaken in my energy comparisons. I suppose I should have done a little refreshing before I started commenting but I did not think a couple questions could cause such aggression. Please note, people can take correction much better when it is given in a mild way.

I am really surprised that you have a degree, are you sure its in engineering?

Even more important, do you now understand what you did not understand before?

This type of heat pump has been around for many, many years. It is simple, well proven and relatively efficient technology. A COP of 3 or 4 is something worth having....with efficient motor cooling, it can even go higher I am informed.......so we are talking about at least 3 nor 4 times better than Ohmic heating.......

I can only say that if I had made your mistake, I would have apologised for my lack of knowledge.....but I rarely need to, because I always try to inform myself better than you seem to.....and I tend to try and keep out of areas where my knowledge is sketchy or incomplete. That is good friendly advice to follow, and not to get personally upset when you put your own foot in your own mouth.....

......most of the ignorant people on CR4 try and blame everything but themselves after such an error. Who do you blame?

The difference between us is that I usually (but not always) know when my knowledge is incomplete.......

I took out my extra comments after re-reading them, but they were to my mind accurate, but my manners would not let me leave them in.....perhaps I should not let my manners get the better of me in the future.....!!!

You call this aggressive?

You should join some other discussions on "the right to bear arms" & "religion" those discussion are really heated.

Some people have a different way of saying things.

As we always said in the RN "If you can't take a joke, you should never have joined!"

These blogs are not for mild mannered, easily upset people......the world is a rough place, CR4 too.....

I personally would say that its good training for every day......I get a lot out of chatting here.....its far better than watching boring TV of an evening, here "my brain cells are stirred but not shaken!"

I would like to apologize to davewho for this discussion getting so far off base from your original question.

Electrical energy was once heat energy, there was a conversion loss from heat to electricity, then it is converted again back to heat, with another loss......

Its far more efficient to use the heat energy directly......

... quite agree.

What got me was something I'd actually assumed - i.e. that the efficiency related to conversion of electrical energy to heat. As this wasn't explicitly stated in the post to which I was replying, that was my bad.

However, time has brought my vindication - "... how inefficient ohmic heating is at converting electrical energy to heat energy ..." appears in a reply to my post.

Doing this with a windmill (the Savonius type is particularly well suited to this and is easy to construct as well) and then using a heat pump to upgrade the heat for the house.

Several windmills could be used and when winds are high, some could be braked to stop the generation of too much hot water.

The containers should be temperature monitored, well insulated, the water should have antifreeze in it. Oil barrels would be a cheap source of such containers and are easy to weld to. Good antifreeze will also prevent rusting.

Such methods have been used in windy areas for many years and can be very effective.

The Savonius is generally a vertical windmill that accepts the wind from any direction and would be easy to DIY such an installation. All you need is wind!

See/click here for more infos and also Google "Savonius".

Hi Andy,

All of the instalations that I have seen in both Norway and Sweden were powered by "Savonius" type wind turbines. Myself I powered my home in Norway with an overshot water wheel because I had a substantial water scource via a large stream that ran through my garden.

Spencer.

Friction welding works so friction heating may also work. Especially, combined with a bicycle...

Hi davewho, There are two ways of doing this, one is to build a water brake and attatch it to a wnd turbine, the water brake can then be coupled to your central heating system via a pump.

The second is to place two or three disc brakes in a barrel of water that is connected to your central heating system via a pump, the disk brakes are mounted onto a vertical shaft that is turned by a wind turbine. You will have to have some method of increasing the pressure on the brakes when the wind is blowing strong.

I have seen both methods working in Scandinavia during the 1960s and 70s.

Spencer.

Simple, just pull up a Grizzly Bear and rub up against him. You will be toast in no time!

Two suggestions:

That looks an awful lot like hard work.

Now sex on the other hand generates a lot of heat and there is some friction involved.

Now blow a fan across that and you might be able to heat up a small area and be fun.

Heating with friction implies some source of mechanical energy: a water wheel, a wind turbine, a willing animal (wife?), an electric motor (horrors!), or even an IC engine (double horrors!). The animal, by the way, will be no more efficient than the IC engine in turning biofuel into work, but the animal will generate warm sweat as well.

Anyway, given, say, a rotating shaft, there are various ways to turn that mechanical energy into heat energy. You can make it rub things together, say the disc brakes. Brake pads are probalby expensive in Alaska. You can stir water, and then circulate the warmer warer to heat the room. You can generate electricity and use resistance heaters to warm the room. Incandescent light bulbs are resistance heaters and work nicely, with the plus that thay can warm your book, too. Or a toaster, or... But electrical friction is probably not what was intended. You could use the shaft to run a trip-hammer, generating heat, but that would be noisy.

Just when you thought I wasn't going to tell you anything new, consider this. Use the shaft power to run an air compressor. Most air compressors are air cooled, with a fan, so that's one source of warm air. Then, of course, the output of the compressor will be warm compressed air, but it will only be warm if it's under pressure; if you release it, it cools. So, run the hot compressed air through a radiator to further heat the cabin. You can pipe the hot compressed air to another room or use it to heat water for your bath. Then you have, left over, cool compressed air, which is still useful, you know, for filling tires, running air motors which can pump your water, saw your wood, stir your martini, etc. etc. You could even run an air motor that would help turn the shaft that runs the compressor. Then you could convince some credulous journalist that you have invented pertpetual motion, and the news coverage might attract a warm female to warm your bed.

Only useful information in the long post was in the last line, that too in the end.

I don't usually read anything that long. I have a short attention sp... hey was that a flying saucer? Oh where was I?