Plumbing Schematic for my application

[bryankloos]

Hey Guys,

Still researching the options for a wood boiler with the existing oil as backup...

I'm having trouble finding the schematic which represents my desired configuration.

I currently have oil hydronic with zone control valves feeding 5 zones (one being an indirect DHW heater).

I want to add a wood boiler similar to schematic PT4, but with zone valve control and not individual circulators on each zone. That said, what modifications to PT4 would be necessary?

Thanks in advance.

Bryan

 

[hiker88]

Let's see if this will work for you. I was in the same boat, except I have three zones. This diagram is a bit older but someone at Tarm gave it to me to help out - has a nice write up too.

I kind of worked off of two diagrams. I used the one I am attaching here for when I got into the area above the oil burner (between the check valves). For all the rest of my plumbing, I worked off the "square tank" diagram, but you could do the same with the pt4 diagram. I found the attached diagram pretty confusing for most of that entire area around the wood boiler, but I had never soldered before I put my system in, so it didn't take a lot to get me scratching my head.

The cool thing about pump p-1 in the attached diagram is that it is an alpha auto adapt pump that just plugs into a 110 outlet. When a zone valve opens, it runs just as much as it needs to, the more zones open at a time, it runs harder.

 

[Clarkbug]

What about using the schematic PT1ZV?

Looks like it has pretty much everything you want! If you already have the zone controller with DHW priority, you should be pretty good to go I would think. Would have to hammer out the details on control for your pumps, but thats a bridge to cross a little later down the road.

 

[bryankloos]

The only thing about PT1ZV that throws me off is the check valve "G". I have no connection from supply to return other than through the actual zones as shown in PT3 or PT4... Other than that, with the addition of the extra zones and DHW heater, it would work. Any thoughts?

 

[Clarkbug]

Are you looking to use storage with your boiler? That will certainly make a difference. Just dont want to try and give bum advice...

 

[bryankloos]

Probably 1000 gal...

 

[Vizsla]

Where are these PT plans? Lookin in the sticks till.

Doing the DHW with a pump instead of ZV is the preferred method by most manufacturers, if you want the spec output. 1" full port ZV don't always provide enough GPM without circ oversize.

 

[Clarkbug]

(broken link removed to http://www.woodboilers.com/images/stories/documents/woodboilerplumbingschematic1211.pdf)

What about just sticking some closely spaced Tees on the output side of the oil boiler, and connect those to your storage with a circulator. That way control is a set of relays, and if you arent running on storage, your system runs just like it does now.

 

[bryankloos]

What about just sticking some closely spaced Tees on the output side of the oil boiler, and connect those to your storage with a circulator. That way control is a set of relays, and if you arent running on storage, your system runs just like it does now.

Closely spaced Tees confuse the heck out of me. I need to read up on them some more...

I've currently got the IDHW fed through a zone valve with one common circulator. No problems with hot water yet but the kids are still young enough that they share a tub. Wen they are teenagers, things may be different...

 

[heaterman]

You must be over thinking it. The late Gil Carlson of B&G put it this way and if you give it about 3 seconds of thought it makes sense.

His quote of the ages was simply this, "What goes into a T must come out of the T."

If you put a pair of t's side by side there is next to nothing as far as flow resistance or effect on the piping they are connected to as long as there is no floe in the loop serving those T's.
Once circulation is introduced in that "secondary" piping the flow from that is added or subtracted from the space between the T's that they are connected to.....but here's the catch....that increased or decreased flow is seen only in the inches between the 2 T's. The flow is immediately returned to the total at the point where the second T returns to the source, be that a boiler or storage or whatever.

 

[Vizsla]

You are way over thinking it. Close T's work just like a hydraulic separator.

Here are some more examples

(broken link removed to http://www.econoburn.com/images/PDF-Covers/Integrating-Wood-Water.pdf)

(broken link removed to http://www.econoburn.com/index.php/resources.html). Goto the idronics link for wood boilers.

The size of your boiler in relation to the load demand, might steer you toward one method or the other. Always plan for storage, even if small like a buffer tank.
The check valve G only makes the oil think or see a moose antler header system when everything else is off. Without it you could have short circuiting depending on the ZV circ size. It can help if the return were further away from the ZV supply. There is also a site called comfort calc, which has some very good explanations of near boiler piping , hydraulic separation by several methods including measured flow thru close tees. He is a regular guy ( boiler man) just like us, so it's not to fancy to understand. Simple is best, but don't worry about an extra circ or two for proper control. And do NOT let the wiring scare you, with the knowledge here alone, its a piece of cake. Whether you go full controls or homemade relays.

 

[SIERRADMAX]

If you want to keep a single circulator & zone valve setup, follow PT4 but only use 1 circulator on the supply. Downstream, branch off with a manifold then add your zone valves. Also, I don't think circ C6 is needed. I followed this but eliminated the near boiler (oil) circ. individual zone circulators pull water through the oil boiler when in operation. Keep in mind, these schematics are good guidelines.

 

[Clarkbug]

Closely spaced Tees confuse the heck out of me. I need to read up on them some more...

I've currently got the IDHW fed through a zone valve with one common circulator. No problems with hot water yet but the kids are still young enough that they share a tub. Wen they are teenagers, things may be different...

Did the links above get you straight on the tees? Or more confused?

 

[bryankloos]

Did the links above get you straight on the tees? Or more confused?

I am more clear now, thanks! I'm still deciding the correct path and timeline, but will make use of the above information in my design.
I'm probably looking at an install not his summer but the next, so I have plenty of time to study the science.

All help is appreciated.

Bryan

 

[jeffesonm]

I too have been thoroughly confused at many points during this planning process... primary/secondary, closely spaced Ts, hydraulic separators, flow rates, etc...... all I can suggest is read read read! It gets better...