Help with new wood boiler install

[Woodsman New guy]

Hello all new to the site and hoping you can help. Background info- I live in PA in a raised rancher on a full finished basement. Total sq ft is 2000. Current set is an instant trinity 150 combi propane furnace which is for my hot water baseboard and my domestic hot water. As of this week I have a new woodsman 400 80 ft from my home. Lines enter into my basement utility room. I bought a 40 plate h/e for heat and a 20 plate h/e for hot water. Does anyone have experience with type of system? I was planning on hooking up from h/e to right before the propane furnace an turnig down the heat settin on propane furnace so it wouldn't use propane. What about the domestic hot water? Any ideas?

 

[Landmark]

welcome to AS. not sure what your question is about your domestic water. I am not familiar with propane water heater. I have electric and when I light my boiler I turn electric water heater off. Also have a 20 plate on it and have never ran out of hot water. Are you asking if you should turn down water heater incase the boiler can't keep water hot enough?

 

[Woodsman New guy]

Should I run a separate hear exchange for domestic? as of now water goes in propane boiler and is diverted either for hot water or baseboard hot water. It's a tankless system.

 

[Woodsman New guy]

If I were to put a 20 onto the hot water line it would suffice enough hot water without a hot water tank? Sorry for any confusion

 

[Landmark]

If I were to put a 20 onto the hot water line it would suffice enough hot water without a hot water tank? Sorry for any confusion

yes. it will supply. when my water tank is off it is essentially pumping cold water straight into the heat plate as if there were no tank. it heats it no problem, and I even have a mixing valve to cool water down a bit, as its too hot without it. can fill a antique clawfoot tub without a doubt. could run it non stop and as long as your boiler is pumping heated water into the heat plate it will heat your domestic without failing.

 

[Woodsman New guy]

Another question, if I install my pex lines into my 40 plate then into my propane boiler in which depend on the call would go to baseboard or domestic do you think the 40 would b fine for both or would you plumb both 40 and 20 into lines?

 

[Landmark]

I am not familiar with the 40 plate. mine is a forced air coil. It is attached to my furnace to heat the air as it goes into the ducts. I have the water heat plate plumbed in first then have the heat coil plumbed in next but have it plumbed so that I can bypass the heat coil and just heat the domestic water in the summer and run AC in furnace

 

[Woodsman New guy]

Oh ok. Thank you very much for your help. I talked to a plumber he ha told me there's no way the wood boiler could do my hot water. How much wood do you burn during summer to heat your water

 

[hupte]

If I were to put a 20 onto the hot water line it would suffice enough hot water without a hot water tank? Sorry for any confusion

oh yea!!

 

[hupte]

Oh ok. Thank you very much for your help. I talked to a plumber he ha told me there's no way the wood boiler could do my hot water. How much wood do you burn during summer to heat your water

in my experience plumbers have big ego's and zero knowledge about wood boilers. my buddy brought in a plumber to help with his wood boiler install. the plumber was highly skeptical about the 20 plate, and 30 plate heat exchangers. he went home, did his homework, and came back the next day highly impressed with the plate exchangers. he also hated pex for some reason, and refused to crimp any pex connections, but by the end of the job he was impressed with pex, and crimping as much as he could.

in the summer months i'll put 6-8 pieces of wood in the boiler about once every 3 days. I dont burn wood all summer just cause it costs more to run the pump than it costs to run my electric hot water heater. but i'm a single guy. also I like to keep my windows open at night so I dont like smelling the smoke from the owb all night if the wind is blowin the wrong way.

its hard to say where you should put the 20 plate without seeing or knowing more about your propane boiler.

 

[Landmark]

Oh ok. Thank you very much for your help. I talked to a plumber he ha told me there's no way the wood boiler could do my hot water. How much wood do you burn during summer to heat your water

I have not used mine for entire summer. the warmer months I have used it burns very little. never even put full load in it and have 24hr burn times.


here's some pics of my setup at the water heater/plate. the yellow handle is the summer bypass valve. plumb a three way switch
into the return line out of the heat plate. one pex line goes to you home heat source other bypasses past it to boiler. just plumb
the return side of your 40plate back into the return and you're good to go.

 

[hupte]

one thing to remember with a plate exchanger is to plumb the water in opposite directions. like if the boiler water comes into the top and out the bottom, then plumb the domestic water in the bottom and out the top. I hope that makes sense.

 

[Woodsman New guy]

Awesome thank you all!

So- one side of heat exchanger is for the wood boiler other wide run opposite direction feed would go into my propane boiler and then the return into the return then good to go for the most part.

 

[hupte]

Awesome thank you all!

So- one side of heat exchanger is for the wood boiler other wide run opposite direction feed would go into my propane boiler and then the return into the return then good to go for the most part.

Its hard to understand your message without punctuation. sorry, not trying to be a jerk or anything... I think you have it though. with addition to your domestic water.
one other thing worth mentioning is that your boiler water and your propane boiler, and domestic water, are 3 separate systems. the boiler water and the propane boiler water never mix. also they never mix the domestic water. I hope that makes sense.

 

[Woodsman New guy]

Sorry, will work on that. But yes that is understood. Can't wait to get off work to get this project underway.

 

[hupte]

Can't wait to get off work to get this project underway.

lol. you got a sweet job!!! lol.

 

[Landmark]

one thing to remember with a plate exchanger is to plumb the water in opposite directions. like if the boiler water comes into the top and out the bottom, then plumb the domestic water in the bottom and out the top. I hope that makes sense.

that doesn't make sense. the boiler water will keep the plate hot from either direction. Domestic water is heated in either direction. the only way this would be right is if the heat plate is hotter on one end than at the other, which it isn't. Even though the diagrams show opposite directions, it will work either way just fine.

 

[Oldman47]

A counter flow is always a good idea for any heat exchanger. It puts the coldest water together on both sides of the plate and the hottest together on both sides of the plate. The boiler water is hottest coming in and the water heater water is hottest going out. If you run both in the same direction you will still get some heat but it will not be nearly as efficient for the heat transfer as a counter flow arrangement.

 

[Landmark]

A counter flow is always a good idea for any heat exchanger. It puts the coldest water together on both sides of the plate and the hottest together on both sides of the plate. The boiler water is hottest coming in and the water heater water is hottest going out. If you run both in the same direction you will still get some heat but it will not be nearly as efficient for the heat transfer as a counter flow arrangement.

Please dont tell my system that. I believe it runs sames direction and has heated 2600 sq ft and our water plus runs a hydronic clothes dryer for 6 winters now and does great. I dont think it matters as much as you think about direction. Sometimes the manufacturing nerds over think themselves.

 

[Oldman47]

I am retired now but in my former life, as an employee in an industry that uses lots of heat exchangers, we used nothing but counter flow arrangements. The real question about efficiency is best seen this way. Say you want to add heat from a 170ºF source to a 70ºF system. In a really good heat exchanger you might raise the 70 stuff to 120 and drop the heat source to 125 fairly quickly. After that no heat transfer really takes place because the fluids are more or less at the same temperature and they just run side by side although you might get another couple of degrees from it. Now set up a counter flow situation and the heat source does lose its heat a bit slower but in the first 10% of its flow path it only raises the heated fluid from maybe 160ºF to 165ºF. In the next 10% maybe it heats the 150F fluid to that 160 and so forth. The end result is that counter flow gives a much closer approach to the heating fluid temperature. You get 165 out of counter flow and 120 out of parallel flow. Which heat exchanger is more efficient? No doubt that both systems provide some heat but we want to get what we can from that heat source. The same kind of thing is happening at the boiler. When the temperature difference is bigger, you get better heat transfer so the 75F returning water picks up more heat than the 125F returning water.