I have a wood stove in my attached garage that sits only 6 feet from our lp furnace. I would like to get the heat into the house and cut down the lp use. I have thought about trying to place a large steel water tight container filled with water on top of the stove and try and gravity flow that into some kind of radiator in the duct work. Having the water gravity feed into a 55 gal drum for water storage and have my pump in that to pump up to the water container on the stove. Any thoughts and best way to approach this. I have very limited budget so this will be a scrap yard build and only purchase necessary items.
Forced hot air? If forced hot air, I am guessing that you have cold air returns. Some how you want to be able to suck that air into the system. I know on my furnace, I can run the fan without the furnace running. Which would pickup the hot air from the wood stove in the air intake.
Forget the pump. If you set up a system that uses natural circulation for your heat exchange you will do better. The stove will heat the water and reduce the water density so you can look at it as an up flow part of the flow path. The heat exchanger in the duct reduces the temperature of the circulating water increasing its density so it becomes a down flow part of the system. If both of those processes happen on opposite sides of a closed water loop, it will circulate by itself and save you having to pump the water.
Man, you better be careful doing that, if you plan on sealing the container air tight? A filled up open container with a closed loop submerged in it-then out to an up-cycled radiator (from a A/C or heater core) at your duct.... Maybe If you get the heights right, you could thermo-siphon. Edit: you partly beat me to it Oldman47
Would the water container and the heat exchanger need to be the same height ? And would an old small radiator other Trans cooler work as a heat exchanger or is there something else that will work better?
Also please keep things dumbed down and real simple terms. I am not the sharpest spoon in the drawer. Lol
I would expect a radiator to work as the duct part of the system if you could seal it inside the duct. Some stoves come with water heater passages which might be a good way to get the water heating side of it. The stove and duct heater do not need to be at the same level as long as each leg of the system ends up above the stove and below the duct heater.
The boiler / radiator idea can work but pulling stove heat into return air duct using a wood stove hood is a no go with a lot of insurance co's FWIW
This is a good question, Bert.... Speculation of course, but either the wife factor comes into play, or the stove may be providing heat to a shop area in the garage.... The man will have to chime in on that one.... A little over ten years ago my brother did something like this- he set a plate-style heat exchanger at or near his wood stove in the basement and pexed up to his garage /shop and piped in a reclaimed condenser rack from an old window AC, squirrel cage behind it just a blowing... That bad boy was the bee's knees I say, the cat's meow I tell ya!
Since you would be drawing air from the garage, I don't think it would be a good idea. Way too many possibilities for something to go wrong with air contamination. Remember the reasons why we don't park our vehicles in the house along with all the paint, fuel, mowers, etc. etc. Please scratch the idea of drawing air from the garage wood stove into your living space. The idea of heating water and then transferring that heat to the F/A system is a good one indeed. There are very simple vids out there where someone just turned coils around the wood stove pipe with copper tubing. I have not seen this in real life nor would I know how to set one up to collect the heat from it. Please remember that running a closed loop would not be a good idea unless there is a safety installed for pressure relief. As we all know, water will expand many times over when it turns to steam. this is why on your home water heaters and boiler systems, the is a relief valve. I'm sure there is a way to run an open system which you can recover the moisture back into the system that would normally naturally condense and evaporate. My OWB is a non-pressurized system with an open vent on the stove top with a simple dome shaped vent cover which allows the condensation to collect and then drip back into the tank.
I agree Dave... I think he's going in the other direction- that being a radiator type of exchanger inside the ducting... I'm all for it, and like you said about closed loop-PRESSURE RELIEF!
Agree with others. With all of the headaches you could likely move it indoors, or just buy an indoor wood furnace. I have a rather large forced air wood oil combo. I love the thing. Expensive on the front end, but I spend only a few hundred for heat in a very cold upstate my climate.
I know in my state just having a woodstove in an attached garage is against codes. They're very very strict on that one. People have a tendency to have flammable liquids in garages.
Well I just hauled a ton of wood today and if not raining will be trying tomorrow to get some more up that is already down. I will try and get some photos tomorrow so you can get a better idea of the current set up and the plan. Thank you all for your input and help. We will make this a successful.
I really don't like to rain on your parade, but in my opinion you could be making a bomb! For example water at 245 degrees Fahrenheit at 30 psi gives an expansion factor of 300,000 to 1. The water in the container you are heating has no way of regulating the fire according to water temperature, so an overheat condition is not hard to attain! Water turning to steam has awesome power. Look for a second hand wood boiler with all the necessary safety controls. What you are planning will work , but might work way too well.
How do feel about an open container (filled and allowed to boil off, provided it gets refilled by way of a float valve)with a closed loop submerged in it campinspecter?
You guys are great. Trust me I will take my time and will be keeping this build updated step by step. I know anything overlooked or can be done better will not go unnoticed by some eagle eyes.
