Outdoor Wood Furnace Info
All-Purpose OWF Discussions => Fire Wood => Topic started by: bruey on October 12, 2009, 08:06:13 PM
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was wondering if anyone has tried or heard of anyone doing this. was thinking of runing 2 new pex lines to my pond and spooling about 1000 feet , sinking it to the bottom where it is about 55 . put a pump inside the house on intake line , shutoff valves on the wood stove pipe, and the air pipe. summer pump the cold , winter switch and pump the hot. somewhat worried about the condensation but i put the air handler at the bottom with a drain plug just in case. i cant see why it wont work, but hate to spend the time and money for nothing. any help out their?????
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i don't think you would have to go to the pond, just bury the pipe in the ground around the house some where the ground temp. is around 55 , also deep enough not to freeze. it seems you could use non insulated line's for this.
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for sure on the non-insolated lines, but still am worried about the humidity, and if it will work.
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Your wonderful idea will surely work! But if I were you I will just spend my time and money with someone who is really capable to do all the electrical aspects. You are bound to ruin a lot if it will fail to work properly.
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I've often threatened to do this.
It will work, and depending on how well your insulation is in your house is how well it work. For example if your house is insualted fair, it might keep the ac from kicking on until it was 75 or so outside, if it was really tight it might extend those numbers up to 80-85.
Yea the coil will sweat of course. It will drain the same as a regular a coil will though.
I've often threatened to run a small pump with about 60 feet of black pex across my roof line and come back to my plate exchanger for my hot water. It does work. we have tried that on a larger scale by placing a spool of black water line on a flat roof in the summer. Water from that system was entering a swimming pool at 190 degrees on hot sunny days.
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Hey Bruey, It's been a good while since this was discussed. Did you ever try out this system? I have set my new system up for this type of cooling but it will likely be a while before I put in a ground loop.
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i hope to add the lines to try this , i have a sistern in front of my house that i would use
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If you do try this, please post some pics and details. My wife would be happy as all get out to figure an air system from the boiler. I was told $3000 + for air hook up to my forced air, aint gonna happen anytime soon.
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i got some old baseboard heaters that ill modif for the coil that will go into the sistern
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I actually did this. I have had a OWB for 2 years and year number one i was sitting outside phila sweating my proverbial you know what off and thought, hmmm i wonder if it would work. So i took out my calculator and figured that using cast iron radiator off of craigs list for free. I needed for my 3900 square foot house I would need 2000 inches of 1/2" pipe for the water entering at 100 degrees F to be reduced to 58dg F ( I have a fresh water spring that moves 3 gallons per minute. it is about 18inches wide and 6 inches deep.
So I dug a little pit in the brook, then I went and got rubber in a can spray (as seen on tv). Then used swimming pool paint. (that didn't work) So then i went with roofing tar from home depot. I put it everywhere then put the spray rubber on top of that to contain anything from messing with the water quality of my spring. So far It works.
Since I installed my pump close to my Forced air exchanger. I use that set up but I installed inside the house several just in case ball valves in case i wanted to add some extra hot water radiator baseboard heat in my basement. So, it cuts off the water from the stove and connects to my 3/4" pex which runs to my stream for the stove. I just placed some black 3/4"inch next to it, hooked it up with the extra valve that I had installed originally and there is a shut off valve in front of the extra valves.
OKAY got that... now here is the tricky part. IT FREAKIN WORKED. however, a small problem arose. It does not get rid of the humidity. Living outside philadelphia/wilmington, DE area it gets sticky here. so, i used my calculator to figure out with my size house that you need to run a 150 qt per 24 hour dehumidifier all the time. Since to buy one of those was about 3500 bucks i said no thanks. however i used 2-72 qt dehumidifiers in the house. Well, i got it to work by august 30th of this past year and bam... cold sept no real heat wave... so it worked and my humidity was around 48 percent for the house which acutally keep the house cool without running the central Air on days more than 80 but never really had bad humidity after that. So, all i know is the first test i did was that I let the OWB run at 90-95 dg F for a week and my house was 75 degrees with 82 percent humidity... That's what spurred on my next set of tests that i reveled here. So, I hope the calculations help you guys. oh copper was better than cast iron you needed less that 2000 inches. But i was looking for a cheap test, so i went craigs list FREE way and used cast iron. So i would show a picture but thing is buried in my stream. it is 2ft tall and 9 loops stacked on top of one another x 2 radiators. So imagine 2 radiators against a wall that are connected by a small nipple then dropped "laying down" into a 3 foot hole in a stream. The water flows on average 3-4 GPM across the fins showing. Above the radiator it is 58 degrees (water temp) and 50 ft down stream the temp is 70. So it does work
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Very cool, Thanks Patrick and welcome to the site.
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For most chill water air conditioning to obtain good moisture removal a good chill water temp is about 45 degF. A 15degF drop across your coil is going to be borderline for good moisture removal (air entering-air leaving). A 55degF coil mite work better for sensible cooling if you tried reducing your air flow to let that air really hang out longer with the coil. It will lower the air temp as well as extracting a little bit more moisture. Just remember to speed it back up again before turning that AC unit back on. I have built two residential water chillers based on the same idea of if your using water why not stick with it. First one was a flop. Second one worked well for a while and began to freeze up, evaporator was too small. Building third one now and hopefully will have all the bugs worked out of this one.
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I was just thinking about this a couple days ago. I am thinking a coil of pipe in the return side of the furnace would work to condense the water. It should be pretty simple to make a coil similar to what is in a dehumidifier. It should work much better without the fins as the metal surface will be a lot cooler.
Then put it in series with the existing heat exchanger.
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UPDATE:
after more tests this summer (kind of a hot one huh?) I have concluded that the system described above works, sort of. We were able to get the water temp. down that was going through the heat exchanger in the air ducts. We discovered using old cast iron radiators was not a good idea. the "flow" of water just doesn't cooperate with my theory. So we changed it to round coils of copper from amazon home brewing beer kit. 3800 square foot house needs 1600 inches of copper or 160 ft or so. great results. it worked hooking up the dehumidifer that is already connected to the system with some simple rewiring to work when the fan is working. I need to create a "manifold" for a summer and winter configurations. it turns out we were trying to cool the water in the wood boiler... man i am an idiot.
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UPDATE:
after more tests this summer (kind of a hot one huh?) I have concluded that the system described above works, sort of. We were able to get the water temp. down that was going through the heat exchanger in the air ducts. We discovered using old cast iron radiators was not a good idea. the "flow" of water just doesn't cooperate with my theory. So we changed it to round coils of copper from amazon home brewing beer kit. 3800 square foot house needs 1600 inches of copper or 160 ft or so. great results. it worked hooking up the dehumidifer that is already connected to the system with some simple rewiring to work when the fan is working. I need to create a "manifold" for a summer and winter configurations. it turns out we were trying to cool the water in the wood boiler... man i am an idiot.
Have you put in a thermometer to see what temps you are getting before the water enters the heat exchanger? I am confident I can keep the house cool enough but I am wondering how low the temps need to be to dehumidify.
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Never ever thought this discussion would end up on this forum.... Wow. I've tried this also, works great! Sort of..... I too had problems with humidity. Cooled well but still sticky. There are so many different factors to cooling its rediculous. I do my own manual j inspection every time we remodel another room (100+ year old farm house) and heating is easy, but cooling is far from. Btus, tons, latent and sensible heat, blah blah blah....
I did learn one useful piece of knowledge though, that every 1 ton of cooling requires a 600 foot slinky coil stretched out I. A trench about 60 feet long if you are going to have a continuously cooling water supply. Otherwise you heat the ground and it takes a long time for dirt to dissipate heat. If you really want to dive in to an amazingly rewarding project, Google "diy heat pump" I've torn into a few window AC units now and use r-290 (propane) as the refrigerant. It's user friendly, legal, and safe with common sense. The entropy cycle is very interesting to study for the technical minded or the extreme diy'er.
I might add, that in order to remove humid you need to be at a temperature lower than the dew point. And have a very efficient coil to cool large amounts of air very quickly, surface area is key. More fins the better. Don't forget you need to have somewhere for that moisture to drain to. A used A-frame coil from central cooling would be a good start.
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When I purchased my exchanger I bought a chilled water coil which is about 20x20 and five or six rows deep. Is it possible to pull enough moisture from the air using just ground temps if there is enough ground loop and enough surface area on the coil? I quick google search looks like dew point varies so I have not figured it all out yet.
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I have an inline water temp gauge from home depot water entering was 90 degrees-ish high 80's