Questions on getting the best of my storage

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warno

Minister of Fire
Jan 3, 2015
1,237
illinois
As of right now my system is only heating my garage, and now that it's finally running really well I would like to get things plumbed to my house.

Details on current heat in house. It's a 1100 sqft home that's 1.5 story. It's heated currently with a 70,000 btu forced air furnace. It's heats fine with the current furnace but if winter is really bad the gas bills tend to get high.

My plan. I have a 100,000btu "rated" WAHX that I already owe. I plan on installing that in my supply duct of the forced air. Which leads me to my question of getting the best from my 750 gallons of storage. I can run my storage up to 180° pretty easy if need be. But my house will need a run of 100 feet worth of underground lines. So my plan is to install a header system in the house crawl space. Then I could run a delta t circ to and from that header system to hopefully utilize ther most of my storage as possible.

My header I'm thinking about building looks like this.

20181231_162650.jpg


Thinking with this header. Supply from storage comes in the top header and heating loads will pull what is needed from the header. If any excess pressure builds in header it will be sent through the bypass. Then returning water from loads will be sent into the return header and back to storage. I'm thinking running the delta t around 30 because my return lines go straight into the bottom of my storage tank. So any remaining "hot" water will mix in ther lower temp storage waters and get wasted.

If all that works I'm thinking about wiring my furnace circ to run on a temp sensor so it continues to run until the WAHX return hits a certain temperature. That's another reason for the bypass on the header. I can shut down the storage supply circ while this is happening then the furnace circ can continue to run through the bypass and use all the heat in those lines and HX.


Does this makes sense to you guys. Suggestions or concerns are welcome.
 
I don't see a need for the bypass. You probably already have a T&P blow off valve in your system. One suggestion though, don't short yourself on isolation valves. At $6.00 they sure do save a lot of aggravation at a future date.
 
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I don't see a need for the bypass. You probably already have a T&P blow off valve in your system. One suggestion though, don't short yourself on isolation valves. At $6.00 they sure do save a lot of aggravation at a future date.

The only reason I was thinking about the bypass through the headers was for when the home heating cycle satisfied the thermostat I could shut down the storage to header circ and allow the home heating circ to continue running until it depleted the heat remaining in the WAHX and related plumbing before shutting down itself.
 
Is there a need for two circs? Since you are contemplating a header, I assume you are thinking of other loads. Maybe a single alpha circ with zone valves for each load. I made headers too but have yet to tap any of the ports, after 7+ years. I use one circ for the house side and one for the boiler circuit in the shop. The house loop runs all winter using outdoor reset, very smooth. You've come a long way, glad to hear you are satisfied with your boiler/storage rework.
 
@BoiledOver

I was concerned about the 100 feet of underground adding too much head loss to the full loop. I did plan on adding other loads. If I go all out it will be the WAHX in the furnace duct, an upstairs base board loop, and DHW.