Copper coils

[windrules]

Hi everone just wanted to know if anyone has tried or if it would work to coil a roll of anieled 1/2 inch copper tube around wood stove flue for a hot water jacket using thermo syphon to move water and how afective it would be.I need to boost my solar HWS as it is useless in winter.

Regards and thanks,

Mos

[DanOpto]

It works!!  They were standard on all old wood stoves. Except the coils were places inside the firebox.

Standard wood kitchen stoves use about 3 feet of copper on the inside of the firebox.

If you must solder joints or elbows within the fire box, use silver solder as it has a higher melting point than regular solder.

Make sure there is no air pocket at any high point that will trap air and stop the siphon action. If you have a high point, you must install a vent to drain out any air that may collect.

I helped make a copper coil in a wood furnace with 1/2 inch copper pipe.

There was about 6 feet of total pipe inside the firebox.

It was placed at the top of the firebox, inside the furnace.

There was a 40 gallon Hot water tank on the floor above.

It thermosiphoned well. No cirulating pump.

In the winter, the couple had to set a load of laundry in the washer before they went to bed to use up the hot water in the tank.

If they did not use up the hot water at the start of the night, the hot water tank would overheat and blow the safety valve.

It is recommended that you install a tempering valve to mix the hot water with cold water so that your tap water will not get too hot an scald your lady. That would not be a good thing!!!!

If you install the tempering valve on the output of the hot water tank, it will control the temperature of the hot water in all the hot water outlets.

Tempering valves are available at plumbing supply houses. They are cheapest if you buy the brass valves that are installed out of sight.

If you buy shower valves with tempering controls, you will pay big time.

[maker of toys]

mmmmm.

1. don't use copper in contact with galvanized steel. it makes a sort of battery, and the steel corrodes quickly;  you can guess what happens afterwards.  I wouldn't want to be in a closed up house with a badly corroded stovepipe. . . .
   
2. wrapping something around the flue seems problematic from a heat-expansion point of view-- the flue is going to move quite a bit as it heats up and cools down, and you're going to wind up with poor contact, and thus, poor heat transfer.
   
   

my feeling is that you'd be better served by getting a piece of black iron pipe  and put the coil inside the flue. (check contractor supply places-there is a line of large-diameter cast iron pipe that's sold for sewer line use, but I don't recall what brand it is.)  (-or- get a copper stove pipe!)   just be sure and always have water in the pipe before lighting the fire, so that you don't burn up the heater coil or load it up with mineralization.

(you might be better served by making a water-water heat-exchanger and running some sort of De-ionized or chemically treated water in the heating coil and using that fluid to heat the domestic water. . .)

-Dan

[ghurd]

Not sure if this helps,

It is quite common to use a coal or wood stove for hot water around here.

Usually (always) the water is circulated around the 'stove' by gravity.

The 'regular' water heater is mostly a storage tank.

Winter has severval variations.

Heating the water always with the water heater, and the water heater

assists the central heating.

(water heater fire always going)

Assisting the water heater with the central wood/coal heating.

(central heating always going)

Variations  related to weather include,

COLD. Both running.

Almost cold. Just the central heat is enough for both.

Cool. Just the water heater is enough for both.

Hot out. Just the water heater, and leave the windows open by the water heater.

This one is coal. Made that way from the start.

The storage tank is an 'electric' type,

because it has the right number of connections.

There is no grid.

The 'Pop-Off' on the electric heater,

regularly blows hot water all over the floor!

Just a fact of life to the owner.

G-

[ghurd]

The big silver do-hicky to the right is the "central heat".

The white thing on top, shadowing the brick, is the thermostat,

and it's connected to a draft control.

A silver manual draft control on the lower right,

and 2 more on the front.

Coal in the square on top.

A 'coffee can' of coal per day supplies hot water for about 7 people.

Most of them teen-age girls!

Yes. That is reams of paper on the floor.

No. I do not know what the white spot is.

G-

[Vince]

Here's a How-To for a 'WOODSTOVE WATER-HEATING ATTACHMENT', and what looks to be some good advice as well:

http://www.motherearthnews.com/library/1984_January_February/A_Woodstove_Water_Heating_Attachment

[geoffd]

A friend of mine lives in a converted fire truck and has 2 copper coils.  One around the stove that gives hot water when they're stopped and one around the engine radiator pipes that give hot water whilst they ae driving.

Geoff

[Nando]

Visit this place, it gives good information about stoves and water heating, if you see the drawing small and difficult to see try to display them larger to show them in good form.

http://www.green-trust.org/2003/fireandwater.htm

http://www.green-trust.org/2003/fireandwater2.htm

Regards

Nando

[Don Cackleberrycreations]

If your using galvinized  pipe for flue pipe I would say the copper corroding it would be the least of your problems. the heat from a hot fire will burn off the galv producing toxic gases