12v immersion heater

[Marco]

Hello, I did a search on 'heating water' to get some info but

can't find an answer to a few key questions.

From what i've read, using a 12v immersion heater, say 300w, driven from a wind

turbine (no battery to keep it all simple), the power dropped by the immersion heater into the water will be proportional to the square of the voltage.

So if my 12v genny is spinning fast and happens to be kicking out 24v (normally

voltage will be clamped if I was using a 12 battery) then the heater would

see 24v and drop about 1200w of power - Is this correct?

Now the problem I could see is the immersion heater being operatd past it's specifications BUT it can't get too hot as it is immersed so it would not burn out -

is this also correct?

Thanks.

 

[Dave B]

Marco,

  I'm plannnig on heating water, no batteries. I've purchased  12, 24, 48 volt hot water heating elements and have been experimenting with these and a variable load controller I designed. You are correct with your calculations but if the heating element is rated at 300 watts 12V then that is when submerged, these will burn out if not submerged even at their rated output. The key as always is to match you load to your output, this is where the variable load controller comes in. I am triggering solid state relays (rated 55A) at selected alternator outputs (rpm). The heart of the circuit is a LM3914 display driver. I'm interested to hear more detail of your alternator etc. as your plans move forward. I've had success so far but it's tricky to dial things in unless you have good constant wind, I'm working on my tower to help that out.  Dave B

[willib]

Dave do you have a link to the heating elements that you purchased ?

i had a link but it no longer works.

[Marco]

Hello, my genny isn't built yet.

I'm trying to simplify things at the design stage

so I've got minimum outlay!!

If it's anything  like any previous DIY i'll only go overbudget by

100% !!

The blade diameter will be 6 to 8 ft.

It's the biggest I can put up without

1. annoying the neighbours and
   
2. destroying my view of the night sky (i'm an astronomer!)
   
   

Plug in Car lighter immersion heater was what I planned to use.

I actuallly have in LM3914 in my cupborard - it was to drive 10 LEDs to

give a reading of my bike light battery voltage!

Thanks for the info.

Have you a website for your stuff?

[iFred]

From what I understand, they sell car emersion heaters for windshield washer fluid heating. (used in the winter) It can heat and pump 1 gallon a minute. I was told that they are available at a Canadian Tire Store in Canada. They should be available elsewhere. Not sure if it's good for continues run but it does work off 12vdc.

Good Luck!

[Dave B]

I plan to get a diary together on this site sometime as things progress, currently I am working on my tilt tower. I think this may be the website for the hot water elements http://www.survivalunlimited.com/diversionloads.htm  There were several different types and as you'll see quite pricey. It takes plenty of power and or time to heat gallons of water to "hot water" temps with the wind. I plan to pre-heat or warm water and on good days this will be possible with my 12' genny. Any thoughts of free hot showers or heating applications I think you're looking at near 20' diameter to be realistic in average wind areas. It's just my opinion based on what I've tested. Keep us posted on your progress.  Dave B

[iFred]

Dave, I have been talking to some heat pump guys. They suggest a heat pump or air conditioner turned backwards and used as a heat pump solves hot water issues. They say that you can suck heat from ice, i belive it..the BTU's are really high when you calculate putting a simple pipe underground and run some special fluid through it. it's three times the energy equivilent of any conventional water heating system if not higher and much much cheaper to run. Then all thats needed is power to run the air conditioner from time to time. Talk to some heat pump guys, they have the anwsers we have been looking for in this area for years. My project this year is just such a system. Good Luck!

[Dave B]

Fred,

  Interesting stuff about heat pumps. A customer of mine had the Geo-thermal heating and air cond. system installed in his new Log Home. The pipe is buried deep in a big trench and the heat pump does the rest as it circulates the constant temp. ground water and takes heat from it in the winter and opposite in summer. He's happy with it, course it's a little more complicated than that as far as hardware but a simple concept. Something to look into for sure, thank you for the tip.  Dave B

[Birdmanjack]

If you go on ebay they have regular 12 and 24 300watt and 600 watt elements that fit a regular hot water heater if this is any help. They are what I am using.