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wood fired water heating coil question | 10 comments (10 topical, editorial)

Re: wood fired water heating coil question (3.00 / 0) (#1)
by rossw on Thu Mar 27th, 2008 at 02:39:15 PM MST
(User Info) http://house.albury.net.au/

A diagam might help describe your setup.

From what I understand you to be saying, your outlet "hot" pipe is actually ABOVE the level of the water in the bath, yes?

If so, I think your "spitting" water is because you're getting local boiling in your tube.

To get a nicer flow of water, I can only see two ways:
(1) Use a small pump (even a little fishtank or garden pond pump)
to push water into the bottom of your coils and maintain circulation
that way
or
(2) keep the outlet below the water surface so it can thermosyphon.

(2) might be a bit hard to achieve without drilling another hole in the bath, but you could possibly get away with using a slightly longer hose, up over the side of the bath and back under the surface. Once you bleed all the air out of the hoses and pipe, the heating of water alone SHOULD be enough to create a continuous but gentle flow.

Re: wood fired water heating coil question (3.00 / 0) (#2)
by wpowokal on Thu Mar 27th, 2008 at 05:48:00 PM MST
(User Info)

I agree the water is boiling in the coil, try a much smaller fire to prove the point, then if possible a 3/4" coil would help.

allan down under
A life lived in fear is a life half lived.
[ Parent ]

Re: wood fired water heating coil question (3.00 / 0) (#5)
by josephcrawley (arecycleryATEyahooDOTcom) on Fri Mar 28th, 2008 at 10:15:48 AM MST
(User Info) http://www.recyclery.org

Thanks for the advice! I don't have power anywhere near that tub so a pump is probably out of the question. I will try placing the tube under the water level to keep the air out. Will it matter that the tube has to rise over the water level before going below it? I guess I'll find out.

thanks
Joseph

[ Parent ]

Re: wood fired water heating coil question (3.00 / 0) (#8)
by wpowokal on Fri Mar 28th, 2008 at 05:27:57 PM MST
(User Info)

Joseph, In my opnion it is not a question of keeping air out, you are creating steam in your 1/2" copper tube. Raising it will slow the thermosyphon and create more, submerging the outlet will lead to some interesting noises.

An expansion tank on the outlet with a top vent open to air say 3/4 - 1" , a side outlet to your tub with a shepards crook of say 1/3 height of tank will ensure your tub gets hot water not steam. Yes you will loose a little of the water from your tub as steam but possibly better than a steam burn.

allan down under
A life lived in fear is a life half lived.
[ Parent ]

Re: wood fired water heating coil question (3.00 / 0) (#10)
by josephcrawley (arecycleryATEyahooDOTcom) on Thu Apr 3rd, 2008 at 12:21:55 PM MST
(User Info) http://www.recyclery.org

Allan,

Thanks for the response. I'm not sure what you are describing with the expansion tank concept. Could you give me some more details?

I have submerged the hose below the water line and this seemed to help to a degree but a constant flow did not take place. A friend suggested raising the bucket so the water did not have to travel quite so far up to the tub. This increased the amount of steam coming out but seemed to decrease the flow of water. Is this because less of the coil is below the water level? That steam makes the most amazing popping sound when it hits that cold water. I took a tub in there this morning for my pre work weekly bath. It took about 40 minutes to get the water nice and toasty which is a lot longer than I would like.

thanks for all the tips

Joseph

[ Parent ]

wood fired water heating coil question | 10 comments (10 topical, 0 editorial)

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