Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: woodburner85 on April 03, 2015, 08:12:02 AM
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Has anyone hooked 2 plate exchangers in series to gain temperature in the water circulating through the baseboards of a house. I have trouble keeping my house warm because the baseboard heat was designed for 180 degree water and am looking for options to increase water temp. Thanks
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You probably won't gain much from the 2nd heat exchanger. The temperature differential will just be too low to do much.
What size is your existing heat exchanger?
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It is a 40 plate
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It is a 40 plate
Instead of using two buy a single higher plate count like a 60 or 70.
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What temp are you running your boiler at?
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If you only have a 40 plate now then going with one large one should help.
Have you checked the OWB water temp out of the plate when it is under load? If it is dropping to near the temperature of the outlet of the plate to the indoor system, you don't have enough water flow on the OWB side and going with a larger heat exchanger won't do much.
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Pump I had was a 009, I just put in an 011 yesterday. Pry won't be a good test till it gets real cold again next year.
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I'm going with a bigger exchanger for next year also. Had a 40 plate and on the coldest nights it couldnt keep up. Reading the descriptions on altheatsupply or whatever it is, looks like i need a 60 or 70. Im gonna repurpose the 40 and put it on the hot water heater.
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Same here going from a 40 to at least an 80 those real cold nights it didn't keep up!
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Well if anyone is looking for a used 40 plate, I will pry have a 2 year old one for sale. Let me know
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Do you heat your DHW with the OWB?
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Yep with a 20 plate and I am able to kill power to the water heater
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I would replace the 20 plate with your 40 plate and sell the 20 instead. The 40 plate will have less head pressure loss so you will get better flow on the OWB. This will help get the most out of the new larger plate.
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woodburner, turn you aqua stat up. I run my boiler at 191 on 180 off. You would not believe the difference in the amount of heat this produces in baseboards compared to 160 to 170. It is honestly night and day difference.
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I run a 60 plate by the way.
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How many zones in the house? What size piping on the exchanger? 1or 1 1/4? A 60plate will come with 1 1/4 piping. 2 or 3 zones on 1in is ok but more will reduce the flow thru the exchanger not allowing enough gpm to the zones. Most baseboard requires 3gpm minimum. So if 3 zones are running it is trying to push 9 gpm thru the plate. You can pipe 2 BPHX in parallel to increase the flow, so both get the hot supply and there is no temp decrease by being in series and the 0011 will give you enough gpm from the woodboiler to keep up with zones. Or you could use a tube and shell style exchanger for pools with 1 1/2 piping and have high gpm thru the exchanger. I used one on a church with 8 zones and 2in piping and it worked great. It was 500,000 btu you may not need one that big but it is an option.