As some here know, I had 4 strokes in March which have left me with weakness in my left arm and leg and balance trouble. This summer I found that I made the most progress in rehab in my mom's swimming pool. I need to keep up the therapy and rigorous exercise indefinitely because I also found out in late August that I also have pulmonary hypertension, which is always eventually fatal but the process can be delayed by considerable weight loss and rigorous exercise. I'm down 70 pounds, and I found a good used soft sided 6'x11'x4' deep portable therapy pool on Craigslist. To heat it, I've been considering submersible wood stoves that are made to heat hot tubs. The first one on the left is the biggest/best design and about 36" tall x 36" wide by 12" deep. These things are typically made of marine grade aluminum and cost $900. A friend thinks I could have one made of plate steel for a fraction of that cost. (That black one is home made out of plate steel.) Anyone have any thoughts on what type and thickness of steel this thing should be made out of? Cost estimates to DIY? I have a friend that has worked as a machinist and welder who is willing to give this a try. Apparently because it's submerged, the stove body is only warm to the touch underwater even with a roaring fire inside because the water absorbs all the heat. We put this pool up in our basement and I would think a 2400 gallon water heat sink would help heat the house too, pretty efficiently. It can be vented out a nearby basement window into a Class A chimney. Humidity is controlled by always keeping it covered with a solar blanket. Otherwise I'll have to heat it with a small underpowered spa heater that came with it, but that burns considerable electricity especially since the 1hp pump has to be run with it. Thoughts?
I would imagine 1/8" or so steel would be all the thickness you would need. It would be a lot heavier than aluminum though.
The pool water is chlorinated so it's going to be hard on submersed steel, which might be why they use aluminum and stainless in some of these. Would 1/8" be adequate when you expect some corrosion on the outside?
The submerged areas might not require high temp paint because it only gets warm to the touch on the water side due to the large volume of water. Could any other paints be used that might better control corrosion in the constant exposure to chlorinated water?
maybe an epoxy based paint, temp should not be a problem. Truck bed liner possibly. I thought this was a joke when i opened it, actually is a good idea. I would think Al. would burn through after a while from corrosion from combustion not the heat. Sorry to hear about your health.
just out of curiosity isn't there an easier way.. most pools come with circulator hoses.. then find a way to heat the water.. never heard of this before.. but how do you add wood tend a fire underwater? just for reference my outdoor pool 20,000 gallon with 1.5 hp pump on a timer ran 2 hour cycles then off for 2 added less than 50 a month to electric bill.. keep getting better BrianK you important to us!
I'll do some thinking on this one. I ran a semi public pool for 10 years and we had Jandy nat gas unit with cupronickel heat exchangers. I like the heat exchange idea like CBVT mentioned. I believe there are propane fired heaters made for pools piped into the pump circulator lines. One sized for a residential pool would heat your water no problem. Have you checked Craigslist to see if any heaters are for sale? Some people take pools down and part out the pump, filters and heaters. The only thing I can think of is a thin stainless steel welded jacket over the steel stove if you go that route. I'll be watching this one and adding anything I can think of. Safety and ease of use is very important for something like this. Take care and I hope this helps in your recovery.
The wood feed is through the square tube at the top with the removable lid. The wood feed and the flue collar sit several inches above the water line. The rest of the stove in submersed and actually has to be weighted down so it doesn't float when it's not bolted to the sides of a cedar tub. An air channel behind the wood feed keeps it well supplied with O2. These are pretty efficient and transfer more heat to the water than any other method.
Just something about a submersible wood stove in a soft sided pool, or any pool for that matter just doesn't make sense to me. Why not an external wood stove or OWB and recirculating water. Even this would work....minus the holes in the sides of your pool.
You certainly have to be careful in placing the stove on top of hard insulation and away from the sides. Otherwise it's been done successfully numerous times. It's far more efficient than any method outside the pool and it's in my basement so I want to keep the footprint small. I do have a small spa heater that's 120v that came with the pool.
I like the novelty of a submersed stove. The natural gas pool heater would be more efficient but it depends on the situation which would work best for you
BrianK I work on Dairy Farms and let me tell you chlorine will destroy plate steel in no time... Chlorine also affects Stainless just not to the degree it does mild steel. Everything we use on farms for the most part is stainless however some is still mild steel and even being close to chlorinated water it degrads very fast. If you could figure out a way to use a wood stove outside the pool and run the water through or around the stack and back to the pool that would last a very long time. I would think even an old stove would work. Wrap pipe around the chimney and maybe pass through in one spot and feed back to the pool. The natural convection should happen with no need for a pump.
