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[Belknap]

I am planning to install gasification OWB and plumb to my wall hung boiler for radiant heat and DHW.  I want to have it so I can still the run the wall hung boiler in the summer for DHW.  Is a hydraulic seperator the best way to go?

[Scott7m]

Are you talking about a plate exchanger?  Often times when hooking to exsisting boilers we'll install anywhere from a 50-100 plate heat exchanger depending on heat load and such

[Belknap]

Do you just put the plate heat exhanger on the supply side of the loop off the boiler?

[Belknap]

intheoaks would you mind taking a picture of your hx and piping setup and post.  That would be very helpful for me.  Thanks

[RSI]

How do you get the air out of the plate exchanger with it mounted upside down?

[Scott7m]

I saw that, there not supposed to be mounted upside down, but he may have got lucky and had its bleed out. 

[RSI]

Bleeders higher arent going to get the air out of the plate.

I wouldnt be surprised if there is only water in half of the plates.

[RSI]

The pump will push some of it out but once it is full to the point where the water is not obstructed by the air it wont push anymore out.

[Scott7m]

The pump will push some of it out but once it is full to the point where the water is not obstructed by the air it wont push anymore out.

I bet your right, I made that mistake once.  It worked but water wasn't as hot as i thought it should be, remounted it and worked fine

[Belknap]

Thanks for the pictures.  It is always nice to see how other people do things.

What size HZ is that?  Do you size them according to the size of the boiler that is currently heating the load?  My boiler in my basement that I heat the house with is 115,000 BTU and the wall hung in my barn is 165,000 BTU.

I was thiking about using 1" for the house and 1 1/4" for the barn.  Does that seem right?

Thanks in advance for all the great information.

[Scott7m]

Depends on how far your going and such.  Pex al pex is an option as well, it's 1.04 vs pex 1" which is .875.  When tying to exsisting boilers I think keeping the flow up is very important, and big plate heat exchangers are needed.  Even if your exsisting boiler is just 115,000 btu, You should want a playe exchanger capable of much more than that, probably at least a 50 plate

[Belknap]

The OWB is going to be around 100 feet from where it enters the barn.  Then to get through the barn and into the house is another 100 feet.

Also with a system like this I am assuming I would just run the pumps on the OWB 24/7.

[Scott7m]

The OWB is going to be around 100 feet from where it enters the barn.  Then to get through the barn and into the house is another 100 feet.

Also with a system like this I am assuming I would just run the pumps on the OWB 24/7.

Yes the pumps would run 24/7... 

You would have to run 2 line sets, one for your barm and one for your home.  You couldn't heat that much space in series. 

The barn would pull off heat, then the home, and it would likely have your return water temps far to low to protect your boiler. That's why central boiler and empyre have boiler protection systems, is to eliminate water returning to cold and making the stove sweat inside

[Belknap]

Yes.  I was going to run 2 lines one for house and one for barn.  I was just wondering on if I should go 1" for house and 1 1/4" for barn.

[Scott7m]

You have to use the proper pump and line combinations, so there isn't one right answer. 

If you use 1 1/4" you could get by with a smaller pump, with 1" it might work for both, but of course your pump would have to be sized larger to make up with the restriction in flow. 

If I went with 1" pex to the house, I'd def go with pex al pex for the increased flow.

Funny this all came about today, had a customer call today who I had worked with before on a very similar distance/application as you.  His dealer sold him regular 1" and his flow is so low it's 40-50 degree difference in supply/return temps.  He will either have to get a substantially larger pump or use 2 pumps in series because his line is simply to small for the application.