30 Mar. 1979|
Make wood fired hot tub heater,new woodworking tools 2015,easy treehouse diy,build a wood turning lathe - Plans Download
In this instructable I will describe how I built a hot tub for less than $100 NZ ($75ish USD) from an old bulk liquids tank, a gas bottle and some stainless tube and junk that I had laying around.
This tub is cheap and relatively easy to build and is also useful as a plunge pool in hot weather too. Heat is easily controlled by adjusting the air draft control for heating the water and maintaining the water temperature.
The heating time varies by the amount of water capacity of the tub and the starting temperature of the tub.
Being that we have bonfires a lot, this would give us an option to do both using one heat source. The stainless steel stove body surrounding the firebox is a double-walled water-jacket with a 1.5-inch space between, making the entire firebox (except the front) a heat-transferring surface.
Water circulates by the thermo-siphon effect: Cold water comes in the lower inlet, is heated in a jacket surrounding the firebox and flows through the top outlet into the tank.
Additional heat transfer takes place in a water-filled baffle tubes that runs horizontally through the firebox.
The baffle deflects the path of the fire, so it gives up more heat into the water jacket before going up the chimney. It also came with a pump, filter, electric heat (i'll still be using a fire) and a blower for free. The TiberLine Wood Water Stove is perfect for cabins or anyone who wants to enjoy a hot tub without any pump noises.
In the winter, our little tank goes from nearly freezing water to a comfortable soaking temperature in less than one hour with just an armful of wood. At the moment i have an old open fire place with a wet back system, but it is a poor conductor so i'm thinking of throwing an old all copper car radiator in its place. I have not yet burned through it, but I do think that the steal tube might be better because there is a lot of residual rust and oil and other dirt in old radiators that doesn't seem to disappear.
And then in the heating system, toward the end of the pipe have some sort of removable filter to catch anything in the water from the metal reacting with your chemicals.
While you want it to be cheam and effective, have to fix it repeatedly wouldn't work so, go with metal tubes. Thermosiphoning occurs due to the heat differential in the coil rather than the whole of the hot tub.
When the heat source is cranking the water temp in the top of the coil will always be hotter than the water coming in the bottom - that's where the driving force comes from.