Yeah, cause we all want a high powered gamma ray source in our broom closet.

Why not heat our Water with small nuclear reactors in the house?

Why not heat our Water with small nuclear reactors in the house?

An excellent topic for another thread, every neighborhood should have one

I agree. At the rate of kids being wizz geniuses, we could have them controlling it. That's a scary thought!

I don't know about the radiation but I doubt your ever going to beat the simplicity and the 100% efficiency of an electric heating element!

Could you clarify this statement, please:"100% efficiency of an electric heating element!"?

You might get some debate there.

Sure just explain what else causes any significant loss, in the day to day practical world, in a heating element that does not get turned into heat in some other fashion. I will either argue or learn something from it!

Even if its only 99% efficient and the rest is lost to electromagnetism or some odd RF generation I would still call it close enough.

"I would still call it close enough."

Close enough only counts in horseshoes and hand grenades. Electricity is the least effective method of heating anything, except for induction heating.

The Op wanted to know about Gamma rays. Why bother to filter them out when the broader available spectrum has 1 Kw per sq. meter of available radiation? Direct sunlight is the most effective way to get heat given current available means. And using thermal mass, heat is the most easily store-able form of energy for reducing your most obnoxious (oil) fuel bills.

Yeah , I chop wood too, but about a 1/3 less than I would need otherwise (zone 4). That's about $600/year here in the Catskills. My system has already paid for itself many times over.

"Electricity is the least effective method of heating anything, except for induction heating."

There are definitely less effective ways... friction heating for example.. but that's besides the point.

I completely agree that of the "typical" heating system, electric is not the way to go for efficiency.

I wondered why water didn't get hot when I rubbed it....

Next time, rub IT and then stick IT in water.......water will warm up, IT will cool down..... Got IT?

10-4 good buddy!

I think that what was meant was the losses involved in turning oil, gas or coal into electricity in the first place. Easily forgotten!

The average residential electric water heater runs at approx 85% efficiency on average.

http://cafs.ahrinet.org/gama_cafs/sdpsearch/search.jsp?table=RWH

Based upon efficiency ratings on an individual basis. Use the above link, put in your water heater and see what yours is rated...

Even the "Point of use" "instant" electric coil water heaters are not close to 100% efficiency.

P.S. ----> NOTHING is 100% Efficient <-----

So wheres the other 15% of my power going thats not being turned into heat by the electric heating element?

I know my gas water heater is rated at 85% efficiency but I am talking about electric.

Energy finds its way out of any system in many ways. Losses of energy are inevitable when converting it from one form to another. In this case when converting from Electrical to Thermal energy, you will have losses in the lines (no wire is 100% efficient), losses in the element itself, the connections etc. But most importantly, when talking about water heaters, is the loss of heat from the system. Its not possible to have 100% heat retention in any system. So even in theory if your element was converting 100% of your electrical energy to heat (which it's not), you will still experience a loss of that newly found heat energy to the surrounding environment before it can be used. The rating is for the whole overall system efficiency thus 85% (mostly heat loss)...

The coil all by itself is most likely operating at a reasonably higher efficiency.. possibly approaching ~98% (which I'm guessing this thread is more about the coil and less about the system)

RV, Your'e forgetting initial losses from mechanical, fossile, or nuclear energy required to produce what little joules wind up at your SE meter. Don't care what your refridgerator says on the door. If you get 20% you're doing good.

Solar to heat conversion is the most cost effictive. What we do after that needs a bit of refinement. Thermal losses are of most concern when there is a broad differential within the system. The temperature here most nights is 45°f, 70-75°f daytime. No heat has beeen applied other than solar. It will stay at 68-66° all night. Unattended the house will not freeze even with 750-850 degree days during the winter. Figure out how much coal/oil would have to be consumed to heat your rubber duckie.

Gotta go, CP

I just researched the efficiency of electrical generation for you, here is a good starter link:-

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

The most modern and efficient methods can just achieve 60%, most are between 35-45% though. Take an average of around 50% overall......that is probably about correct.....

Does that explain the losses involved better for you (and anyone else)?

Nope you successfully side stepped the point and purpose of the question though.

So I will spell it bigger and louder for you. WHAT I ASKED ABOUT WAS SPECIFICALY THE EFFECENCY OF THE HEATING ELEMENT. NOT ANYTHING BEFORE THE HEATING ELEMENT. GOT IT?

JUST THE HEATING ELEMENT IN THE WATER TANK OF THE WATER HEATER. NEAR 100% EFFECENT AT TURNING ELECTRICAL ENERGY INTO HEAT OR NOT?

Not to have sounded rude but I see too many experts here that just don't seem to grasp the simple concept answering the question about the device or object in question and not the entire process the leads up to it.

I don't care what efficiency the entire system is leading up to my watt hour meter for my place. My only concern is the efficiency of the devices after the wattmeter.

Show the calculations describing the equality of watts input to BTU realized...

Then show the calculation with one mil of calcium deposit on the element...

Then show the calculation detailing the duration which 100% efficiency can be attributed to an electric heating element in real world conditions.

You may have missed tcmtech's original post. In it he says:

I don't know about the radiation but I doubt your ever going to beat the simplicity and the 100% efficiency of an electric heating element!

He is correct that electric heating elements are 100% efficient. For each kWh input energy, you get the equivalent output, from the element, in BTU's. So the equation is, for a 1 kWh example: 1kWh input = 3412 BTU output.

If you coat the element in calcium deposits (or glass or ceramic) the equation does not change. The heating element heats the calcium (or the glass or ceramic), and the calcium (or glass or ceramic) heats the water. If the deposits do not conduct well, then the heating element temperature rises, eventually burning out. But all the heat has to leave the element... otherwise what would it do? Convert itself into chemical energy or light, or mechanical motion?

If you propose that some of the kilowatt input to a heating element is converted to something other than heat, then what might that "other" be? As you may know, a 90% efficient electric motor gives off 10% of the input energy as waste heat. What would a 90% efficient heating element give off as waste... rotary motion?

From a Wikipedia article on electric heating, under the heading "Environmental and Efficiency Aspects":

For an electrical energy customer the efficiency of electric space heating can be 100% because all purchased energy is converted to building heat.

Show your calculation for a one mil of calcium deposit on the element.

I'm sure its negligible, but what about the EMF field that Electric Resistance heating elements produce? I'm sure some energy must be converted to the magnetic field, and i'm sure that they do indeed produce a magnetic field, otherwise why would people be coming up with non magnetic field producing elements?

Nuclear "Gamma ray" water heating!

Negligable is the key word for low frequency ac fields. The slow field changes don't radiate like radio waves.

Do you suppose that non magnetic field producing elements is a way of getting away with the higher price?

Bifilar heating elements are good if they are near your sensitive electronic stuff.

People are concerned about living near high voltage power lines and they probably avoid stepping on cracks in sidewalks too.

In modern hand-soldering equipment a 13 mHz electromagnetic field induces heat through skin effect on a pellet that has an exotic alloy that reduces its skin effect characteristic as the operating temperature is reached. It is all nicely shielded but I can still pick it up on my shortwave radio. (Induction heating.)

Jon

If you heat water with electricity, in most countries it costs MORE than directly heating using gas, oil or coal. (Assuming a proper "burner" for the fuel in question!) How much more it costs depends on the price of the various fuels against it.

If price is no object, then electricity will probably do it fastest and with lower (actual), losses, but at a higher price per watt, due to the price/losses associated with electrical supply and generation.....

Of course if you are generating your own electricity from wind/water (or stealing it via an illegal cable!!), this may still be interesting for you.

I do feel that you are asking a question and making it more difficult to answer by giving little or no background infos.....and then "SHOUTING" because we are not seemingly performing as expected!!! Not very impressive of your standard of manners I must say!!! We all perform at no cost to you.........so what you get is EXACTLY what you paid for!!!

What back ground info do you need? A competent EE would easily have gotten all of the information from my simple and direct question. As I stated earlier I was not intending to be rude. Sorry if it came across that way. My apologies.

I often deal with people that cant answer simple questions without having it repeated ad nauseam in order to get a them to admit there is a simple answer to a simple and direct question.

If I ask you what color is the sky? Would you tell me its typically light blue or slightly grey? Or would you give me a lecture on light, properties of gases, and theory on how the photo receptors in my eyes work? Just because you know something complex about a topic in question doesnt mean its the correct answer for the stated question.

I grew up on a farm and a saying I came to know well is "You cant always lead a horse by hand. But you can always lead one with a tractor!"

For those of you who don't get it. A horse is stronger than a human but a tractor is stronger than any horse. Willing or not they follow!

Actually, an electric space heater is effectively 100% efficient. Any "losses" go off as heat, which is not wasted, because that is the desired output of the system. Flim-flam artists claim that oil-filled heaters, or ceramic heaters, etc, etc, are more efficient than others, but they are all equally efficient, and convert essentially 100% of the energy leaving the wall outlet into heat. Even the small amount of light that some produce is turned into heat when it hits the rooms walls. This is true whether the heater has a blower or not also, because the air motion is converted to heat as well.

On the other hand, whatever is feeding your wall outlet is anything but efficient, so electric heat costs more than gas heat, because when you buy electricity, you are paying for the waste heat at the power plant. A home gas furnace is about 85% efficient, whereas the grid is less than half that efficient.

Compact fluorescent bulbs are only more efficienct, overall, in the summer. In the winter, the "waste" heat from incandescent bulbs helps to heat the house, so between heat and light, an incandescent bulb is 100% efficient: it doesn't give off any waste.

Yes it can. However, considering the amount shielding required and the difficulty in obtaining a source of gamma radiation, it's just not practical. And then again, of course, are the unforeseen potential side effects.

would too much gamma rays turn us into........THE HULK?????...."don't get me angry, you don't like me when i'm angry"...

Use solar radiation.

Okay, the question was about gamma rays heating water. In a reactor does the water get heated directly by the energy, ( alpha, beta, gamma, neutron), or is it from the fuel mixture heating up and transferring the heat to the water?

Any particle or photonic radiation that does not EXIT the reactor, decays or is eventually stopped and gives up its energy as heat. This happens throughout the reactor, but the bulk of the heat should come from the fuel assembly. Sorry, don't know the exact numbers.

The vast majority of gammas will go straight through the water with no interaction.

In a fission reactor, the heat comes from the energy released when a nucleus 'splits', giving off neutrons and gamma radiation (maybe also α and β).

Water may be heated by the neutrons (fast neutrons interacting with the hydrogen nuclei, slowing the Ns and speeding up (i.e. heating) the Hs), but not significantly by the (relatively minute) gammas.

The radioactive material and its ions don't have to touch the water to heat it. An RTG assembly doesn't need any control devices either. It just makes heat and the container it's in is a shield and gets hot and stays that way until it dies.

Jon

Agreed, but the OP (and the point in the post to which I was responding), was about heating the water with gamma radiation.

Yep, I see what you mean.

"Could water be heated with radiation such as gamma rays?"

Nope.

Jon

If you can get heat from a radioisotope to make electricity (Radioisotope Thermal Generator) you can heat water without the radiation too.

Heating from passive radiactive decay uses the fact that radioactive materials (such as Plutonium-238) generate heat as they decay into non-radioactive materials. The heat used is converted into electricity by an array of thermocouples which then power a lighthouse or an interplanetary space probe or keep a Mars rover from freezing.

There is no reason you can't heat water with it as well.

Tea anyone?

Jon

So long as the water is not "HOT" in BOTH meanings of the word!!!

More efficient? I think so.

More efficient than other methods due to the fact that Gamma rays and their source is energy going to waste if not harnessed. Harnessing equipment and maintenance would seem to be the only inefficiency.

Heat going to waste?

Geothermal:

Across all of Iceland, 90 percent of households are connected to a district heating system. That was heat that was just going to waste but is now put to use. Any inefficiencies in that system can be discounted.

99 percent of Iceland's electricity is produced from renewable sources, 30 percent of which is geothermal, the rest is from dams. When transportation, heating and production of electricity are considered as a whole, geothermal provides half of all the primary energy used in Iceland. There are efforts underway to use the island's supplies of renewable energy to power its fishing fleet and motor vehicles through conversion to hydrogen fuel.

I wonder what will run out first? Geothermal or Radioactive materials.

Jon

Gamma Rays are routinely used for medical sterilization. I use gamma radiation regularly. They do not heat water as water is transparent to those frequencies.

Confirmed.

See message 35.

Jon

Why You not stop the fight? gamma rays make hot head not water.

heating element is for plumber not engineer.

I didn't read all the threads, but did anyone mention microwaves? Pulsar Advanced Technologies has a new unit available soon. I always thought this would work, just didn't want to play around with beamed energy. Makes your babies look funny. Gamma rays will make them look real funny.