POOL HEATER

[ryansteele]

Ok, to start with, i know Im trying something that has been BEAT TO DEATH !!, but I'm stuborn I guess. LOL

So I want to "build" a wood fired heater for my 27' round AGB. I live outside any incorporated area, in New Brunswick Canada, so my pool season is way to short! My closest neighbor is 1500 meters away ( and it's my wife’s parents ), other then that it's just me!

My plans are to take a "barrel stove" http://www.vogelzang.com/images/BK150ELRG.gif , and wrap it in 1" soft copper tubing from front to back, input going in on the bottom of a wrap at the front, and ending at the back of the barrel on the top (hoping this will help with the natural movement of hot water). I also plan on wrapping the entire contraption (barrel & pipe) with aluminum insulation, and have considered placing the entire stove in a wood furnace case I have that has had the firebox removed, putting a pitched cover on it and possibly filling the entire case in sand, to aid in heat transfer to the copper first then the water. I know the risks of a "closed" system and a steam explosion, but if this is run with a separate pump, intake and output to the pool, so NO ball valves to accidently create a "closed system", in my mind there is no way to trap the boiling water and steam.

Now this is in its preliminary stages, I am FAR from a engineer, I am actually a paramedic by trade, so I am looking for all you pessimists to tell me why this wont work. I have a few concerns of my own..... A.) will it even make a difference? My original plans were to put the coil INSIDE the fire box, but after further consideration, thought the exterior heat sink might work better. B.) is it dangerous? C.) if it works is there anyway to safely attach it to my existing pump system with a simple bypass valve?

Any comments would be welcomed

 

[ryansteele]

well i guess i should have done more research,,,,

http://www.gsplans.com/pool_heater_plans.html

plus from what i can read here, the general feeling is that it will take to many BTU's to raise my water temp much.

 

[spishex]

Dave (Duraleigh) can tell you a little bit about his experiment trying to heat the pool with wood. Basically, the pool becomes a giant radiator that does nothing but cool down your heater faster than it can heat the pool water. Wood can be used for a small, hot tub sized body (<1000 gallons) but pools are pretty much out of the question.

 

[JasonLion]

Welcome to TFP!

It takes an astounding amount of heat to warm up a pool, often several times as much as heating your house. It can be done, but you will need a huge amount of wood and a very large heat exchanger. Here is a real world working example of what is required.

To give you an idea of the scale of the problem: Wood varies quite a bit, but call it 20,000,000 BTUs per cord (good but not excellent hard wood). A typical pool heater might be 200,000 BTUs per hour. So a cord of wood will run the pool heater for about 100 hours, assuming you have an efficient heater design. This time of year, here in Maryland, we use that much heat in three or four weeks. Further north it won't last nearly that long.

This kind of thing can be done, but you need to be really into it.

 

[stever]

Wood pelet stoves can output a lot of heat and are auto-fed with thermostat control. With all of this and a good radiator.... maybe? I'm thinking of a radiator closer to that of an car or air-conditioner with lots of fins, etc.