Magnetic induction for hot water heaters?

Well I have an induction hob that heats water in a steel pan very efficiently.

I can't see why some steel tubes couldn't be arranged in the magnetic field to produce hot water...

But why? having a heater immersed in water will give you almost 100% efficiency in transferring the power into hot water...

Using induction heating will give less efficiency.

John.

Someone has developed an induction water heater that is more cost efficient than traditional water heaters, when it is used during the night with low tariff electricity.It is being sold in Israel to old age homes to replace electricity hot-water systems that heat water during the night for morning bathing of bed-ridden people. It may also have been sold to factories that have lots of night-shift employees that shower at work early in the morning after work. I searched and searched the Internet for other commercial units of this type, but haven't found any. I guess the owner of the patent for this induction system is correct when he says that there is no competition.

Hi Electroman,

I cannot see why this cannot be done, this system of heating is often used in labs that produce synthetic gemstones. To produce Zirconium Oxide gemstones( cubic zirconia), they put Zr O powder in a crucible that is made of a tght cage of half inch copper tubing, water is run through the tubes to keep it cool. To heat it up to 1200C they place it in a chamber that is then bathed in RF.

If they can do that then I am sure they can heat water this way, but what is the expence?

Spencer.

Wouldn't technology that is competitive on night rate electricity also be competitive on day rate electricity? Or are you factoring in payback time based on initial cost? The induction technology is more expensive on first cost but can pay back the difference in a reasonable time on the night rate?

I guess that the payback issue is what makes the induction system cost effective at night rate electricity. Glad that you brought up this issue. Will check it out. I'm a curious person, but not an engineer.

I have given the co. behind this product a proposal for market research. Til I "get" the project, I don't have to get into the induction product. BEFORE I wrote the proposal, I wanted to see what competition was on the market. When I didn't find any, I thought to try this discussion group. God only knows how I found it. I'm not an engineer, but I still get email from Global Spec, in connection with a market research project I once did (10 years ago!). Thank you all for your valuable comments. The Internet is great.

Hmmmmmmmmmm sounds to me like its another 'get rich quick' scheme...

Standard water heaters used to heat water using off-peak electricity would be far better than complex and expensive induction heating...

John.

Hello,

Now I will straighten things out.

The induction hot-water heater about which I wrote is particularly cost effective when used with low night-rate electricity, and compared to hot-water heaters that work on gas and diesel fuel.

When compared to hot-water heaters that work on electricity, "my" induction system is only a little cheaper. In this case, the Return on Investment is over 3 years.

I apologize for the misunderstanding I caused. But I would like to thank everyone for helping me see my mistake.

Best wishes, ARA

A resistance heater will be approximately 100% efficient in converting electricity to heat. An induction heater will be somewhat less efficient due to switching losses in the controller which converts incoming power into a higher frequency that the heater can use. Gas and diesel will always be cheaper than electricity for heating, unless your electricity comes from hydro power or a very bare-bones, lightly regulated nuclear reactor. If you are using off-peak hours to heat enough water for the whole day, a resistance heater will heat just as much water with less electricity and cost much less to buy and maintain.

Agreed Dave, as I said in post #1....

Electroman,

You did say that in post#1, my intention was to expand on the reason.

LG_DAVE

Maybe I should learn to type a little faster so I can answer a question in as much detail as I'd like.

Or maybe I should just sit on the sidelines and give out GA for people who have typed a more detailed and clear answer?

Thanks - John

Lighten up electroman - no offense was meant

Absolutely none was taken Dave - honest

90 percent efficient compared to 50 percent with gas or 70 percent with immersion element. for more specifics go to http://ultraflexpower.com/learn/efficiency-of-induction-heating/

I am of the opinion that a hot water immersion electric heater is around 99% in terms of efficiency. The only energy into the heater that does not end up in the water is a small amount conducted out the immersion element where an unheated portion sits in air and some travels out.

Gas water heaters of the condensing kind in homes are over 96% as they use countercurrent means to exit the combustion gasses at the input water temperature, with the water of combustion collecting as drips to a drain.

Induction heaters - if you made a totally immersed induction heater it would also have a very efficiency.

Any king of strap on tank heater, be it induction or resistance would be at least 10% less efficient

Why would you have a hot-water heater in your house? If the water is already hot, why would you need to heat it? Wouldn't you instead be heating cool water to make it hot?