Setting up OWB

[vinrum]

I am running a plate exchanger, and my question is? I have a inch and half supply on my oil furnace, and I was wondering if I could cut 2 T's into the supply and hook the in and the out of my plate exchanger to just the supply side of the oil furnace..I was going to put a shut between the T's so the supply water has to go through the plate?

 

[vinrum]

Or could I just cut the supply and put the plate right in line? Or would that restrict the flow

 

[RobC]

I haven't done a heat exchanger set up so I can't advise on best placement but I would set suggest you plumb HX so it can be removed easily for cleaning if necessary. I believe some also will use an inline filter.
Second have you given thought to how the OWB and OB are going to be controlled together ? This might also effect placement. For example if you placed the HX in the return line to OB then the OB would "think" it was always hot. This may be the simplest way to hook up but not the most efficient because your keeping the OB hot all the time and you will have standby loss. VS the supply side the return water after zones will be cold. Boiler will think it's cold all the time. Does your OB have tankless hot water coil ?
To advise on a good location I think you may need to provide a bit more details on your system layout.
Your asking in the right place....

 

[vinrum]

Rob, the hot water heater is a indirect Weil McLain.. I under stand what you saying about the return line,.Do you think I should make a loop between the supply and return and run a circulating pump so the OB is always at temp? Also, my current Oil Furnace is being controlled my a 4 zone Taco box, that controls 3 circulating pumps. 1st floor, 2nd floor, and Hot water heater. And I have one spare zone still in the box. The system is a Hydronic system with 2 Air Handlers, 1 in the cellar, 1 in the attic. And the OWB has a 1 zone taco box that turns on the pump for that

 

[bigburner]

what kind of HX, do you know pressure drop ? If it's a big one there should be no pressure drop issues. Now how do you want your system to operate?? Hot boiler,Cold boiler?? My advise would be to keep every thing on the oil side operational, also this can give you freeze protection for out door wood boiler. [pump on] If it were me and I was using a basic OWB I would run the hot boiler and put the HX in line [but plumb it with enough vales for a by pass] use a strap on aqua sat that will electrically isolate the oil boiler from the OWB, and when temps fall [didn't get out of bed and feed the OWB] the oil boiler turns on. In this set up you could fill the OWB on Friday night, leave for the weekend and not worry about a freeze up and the house would still be warm, I don't recommend antifreeze, it's cost to much and the little bit of oil used to prevent a freeze up won't buy much antifreeze. JMO

 

[RobC]

One way to control a OB and an OWB together it to run 2 thermostats, where the OWB thermostat is set a couple of degrees higher than the OB. If for some reason the OWB doesn't supply heat the OB kicks on. I don't know how to incorporate that to a Taco controller but those are nice and I'm sure it can be worked out.
Here is a thread on plumbing a Garn which is a non pressure Gassifier. So this would be the same set up as yours. If you follow some Garn threads you will come up with a ton of info on plumbing options and controls. About A year ago RowCropRenegade did some long and informative threads on Garn his build with many pictures. rvtgr8 also did a nice posting.
https://www.hearth.com/econtent/index.php/forums/viewthread/53699/

 

[RobC]

Big burner makes a good point for freeze protection.
Whats your boiler ? Pipe size to and from OWB to HX ?

 

[RobC]

Here are some other diagrams....
http://wdheat.com/installation-scenarios.html