Improving storage flow

[grumpy chief]

Hello, new member here. Have been reading the stickeys and older threads but have questions. I have a seton w90 I started using 5 yrs ago. 1st year terrible but learned quickly. Last year I was able to locate 2 500 gal propane tanks for storage. I cut into the existing lines between the boiler shed and basement and using sharkbites I T'd them in as the attachment shows. Last year I also changed the main circ pump to a yellow jacket and tried the dif T option. ( ended up using constant pump since the boiler would overheat when trying to get 180deg loop temp). Anyway I have the tank access open and was wondering if there are any suggestions on how to improve storage temp. I know now that the current piping is not optimal since I used a pipe from the top fitting to reach the tank bottom ( at least I read this gives poor stratification). Maybe next year I could mount one over the other and use the bottom fittings to get the best flow. Looking for the best way to get storage water through the boiler and up to temp. I have the original circ pump (taco 007) and thought about putting it back in as the main circ pump and somehow using the yellow jacket to get better flow through storage. All last year I never felt the storage temp was high enough. I am able to get the seton to burn cleanly and make hot water but feel the storage is not getting hot enough.
I currently have a calefi 280 series temp valve on order. I will add it in for boiler protection. Just took all the covers off and cleaned the heat exchanger (annual) very little creosote compared to previous years. Lot of grey flakey material on tubes but no creosote clogging the tubes. yea storage tanks.
Thanks for reading, Craig

 

[easternbob]

Craig,
What kind of temps are you getting in your storage? I know the dip tube on my propane tank was pretty small diameter if yours is the same it might be tough to get proper volume to flow thru it. I welded a nipple (think it was 1.25") on the bottom of the tank to make sure there was sufficent flow.
There any many other people with much more experience, hopefully they have some thoughts for you.

 

[grumpy chief]

Thanks, My dip tubes are 1" black pipe. I drilled out a 1 1/4 bushing and welded a 1" pipe with thread out the top to attach my pex barb fitting. Sorry to say I don't remember my readings from last year. I was opening a access panel and reading the pex in and out tube with my infrared gun. Been meaning to get some type of sensor and gage to be able to read from outside the enclosure.

 

[Clarkbug]

Grumpy, maybe I missed it, but is there a pump or something that charges your storage? Otherwise I don't see anything that would cause water to flow into/out of your tanks...

 

[NateB]

I would put in a pump to pump into your storage, and I would control that pump with a solar controller. The controller would watch the return temp, and when it is high enough(meaning the house is not calling for heat) turn on the pump to start storing the heat in the tanks. this is the one I bought http://www.supplyhouse.com/Tekmar-156-Difference-Setpoint-Control-On-Off-7954000-p

Hope this makes sense. Feel free to ask questions. I am still in the process of setting it up, but it seems to do its job well.

 

[grumpy chief]

Grumpy, maybe I missed it, but is there a pump or something that charges your storage? Otherwise I don't see anything that would cause water to flow into/out of your tanks...

That's correct, no pump. I don't show it but I have ball valves at storage T fittings. I would manually throttle down supply loop and fully open supply line to tank. At night all valves fully open. I am home 24/7 so keeping stove burning and manually manipulating valves is how I managed boiler protection and heat to storage. Am going to install the calefi 280 series when it arrives to automate boiler protection temp. So correct, no pump to storage which is why I was wondering if the yellow jacket and its delta T option would/could be utilized. Or any other suggestion to automate storage heat transfer.

 

[grumpy chief]

I would put in a pump to pump into your storage, and I would control that pump with a solar controller. The controller would watch the return temp, and when it is high enough(meaning the house is not calling for heat) turn on the pump to start storing the heat in the tanks. this is the one I bought http://www.supplyhouse.com/Tekmar-156-Difference-Setpoint-Control-On-Off-7954000-p

Hope this makes sense. Feel free to ask questions. I am still in the process of setting it up, but it seems to do its job well.

Thanks for the response. Was thinking the yellow jacket could do something similar with its delta t, or set point options. Just not smart enough to figure out exact /best way to get it done.
Also I am at the point I could redesign the storage plumbing to closely spaced T for in and out and add a circulator similar to primary secondary loops. Adding the calefi valve allows me some freedom to rearrange lines in the boiler shed.

 

[maple1]

You only have the one circ pump for the whole system now?

I think I would use two - one for just the system that pumps thru the rads (the yellow jacket) on a call for heat, and the other (007) between the boiler & storage that only pumps but pumps all the time when the boiler is firing.

OK, looked again. Two other pumps, one for each zone. That is almost a primary/secondary setup. The problem with just the one pump on the boiler loop is that it is sending most or all of the flow around the heating loop when the boiler is running. Do you have a diagram for how you are thinking of changing the piping when you add the Caleffi? You should incorporate the 007 to work with that, and it only would pump when the boiler is heating. Sorry, don't have time right now to suggest changes, gotta run....

 

[NateB]

Thanks for the response. Was thinking the yellow jacket could do something similar with its delta t, or set point options. Just not smart enough to figure out exact /best way to get it done.
Also I am at the point I could redesign the storage plumbing to closely spaced T for in and out and add a circulator similar to primary secondary loops. Adding the calefi valve allows me some freedom to rearrange lines in the boiler shed.

I am not sure how the yellow jacket works, but if it has 2 temp sensors and will work off of the delta T. You could watch supply and return, and when the delta T starts to shrink you could turn on your storage pump, and when it gets to the +20* delta turn the pump off.

Hope this helps.

 

[grumpy chief]

You only have the one circ pump for the whole system now?

I think I would use two - one for just the system that pumps thru the rads (the yellow jacket) on a call for heat, and the other (007) between the boiler & storage that only pumps but pumps all the time when the boiler is firing.

OK, looked again. Two other pumps, one for each zone. That is almost a primary/secondary setup. The problem with just the one pump on the boiler loop is that it is sending most or all of the flow around the heating loop when the boiler is running. Do you have a diagram for how you are thinking of changing the piping when you add the Caleffi? You should incorporate the 007 to work with that, and it only would pump when the boiler is heating. Sorry, don't have time right now to suggest changes, gotta run....

My original setup was based on primary secondary as I understood it. I added and used hand ball valves to force hot water through the storage, not a great setup but did work. This year trying to automate and improve storage operation. Diagram of boiler protection valve and possible change to closely spaced T with a possible pump?Link Removed

 

[maple1]

If this post works - I quickly scribbled in a few things to think about. I would put the yellow pump on just the heating loop, pumping on call for heat only, and the 007 that only circs through the boiler when burning - that is its only job, move heat out of the boiler. When the boiler burns out & the 007 stops, the yellow will pull thru storage in the direction opposite that of when the boiler is burning & the 007 is running.


That is just meant to show a couple of principles - there are other things you would need to sort out, like controlling when the 007 starts & stops. The main thing to think about in something like that is a very simple one but easy to overlook - the load circuit that has the yellow circ in it needs to see more head or resistance in the piping on the boiler side of those Ts, than the storage side. Then the water will flow through storage and not the boiler when the 007 stops pumping. No manual intervention or other controls should be needed. So more pipe, or more fittings, or bends, or whatever, between the T & boiler, than T & storage. I also turned the Ts around so the load-storage circuit straight shoots thru the Ts - less resistance to/from storage.

Just ideas - I am no pro. Hopefully you will get more feedback.

But one more thing - what do you have for overheat protection for the boiler? Seems to me the Setons are easy to overheat, and most storage setups rely some on convection through storage in a power outage. Which I don't think is possible here - so you should have some radiation directly overhead of the boiler plumbed through a normally open zone valve that could dissipate heat if the power goes out.

 

[grumpy chief]

Studying your drawing and will count up resistance issues tomorrow to see if the flow will reverse due to pressure difference. Originally had a fan and radiator that kicked in when the boiler reached 190. Last year I removed them and used them in a garage heating loop that is not shown in the diagram (another secondary circuit beside the house circuits.) That being said I operated last season without power loss protection. Remember in my original post I stated I had to reset the yellow jacket from delta T to constant pump. When the primary loop was running around 160 with a fire and the house heat shut down the pump did not seem to ramp up fast enough and I would get short spikes of damper door opening and shutting with occasional overshoots that reached 210 and once popped the temp relief. Just learned how and when to load wood and kept operating, I am planning on setting a greenhouse beside the boiler shed and then will reinstall a heating and boiler protection setup with excess heat going to the greenhouse. I have an invertor and holding relays ready to hook up for power outage, need batteries but have to set priorities. Generator is prewired currently just takes a few minutes to start up. Thanks Craig

 

[Clarkbug]

Studying your drawing and will count up resistance issues tomorrow to see if the flow will reverse due to pressure difference. Originally had a fan and radiator that kicked in when the boiler reached 190. Last year I removed them and used them in a garage heating loop that is not shown in the diagram (another secondary circuit beside the house circuits.) That being said I operated last season without power loss protection. Remember in my original post I stated I had to reset the yellow jacket from delta T to constant pump. When the primary loop was running around 160 with a fire and the house heat shut down the pump did not seem to ramp up fast enough and I would get short spikes of damper door opening and shutting with occasional overshoots that reached 210 and once popped the temp relief. Just learned how and when to load wood and kept operating, I am planning on setting a greenhouse beside the boiler shed and then will reinstall a heating and boiler protection setup with excess heat going to the greenhouse. I have an invertor and holding relays ready to hook up for power outage, need batteries but have to set priorities. Generator is prewired currently just takes a few minutes to start up. Thanks Craig

Just be careful with using your greenhouse as the overheat loop, since there is potential for it to freeze if you arent also actively heating it (and the space between where the lines run)

Do you batch burn in your Seton, or does it run continuously during the heating season?

 

[grumpy chief]

Would say some of both. Morning time would be several small batches, maybe a midday, then two loads to bring storage up. Never loads over the door bottom ledge. I have a actual thermometer that the probe is in the middle of the 8 in schedule 80 pipe chimney. I try to keep the fire where the temp is about 400, I found that is where the refractory is clean and the boiler is not cycling. Although I never let the fire completely out except when I clean out the ashes. very seldom have to refire. I don't burn large unsplit rounds. 8 - 12 in round would be quartered therefore I have a lot more surface area available to burn. Actually the greenhouse will share a common wall with the boiler shed and have a door between the two. Seems a shame to waste the heat inside the boiler shed. Shed can at times become a hangout.

 

[Bob Rohr]

I'm not sure how much repiping you would be up for, but there are some simpler ways to pipe that system and give it all the functions you want.
Also it would be best to have one expansion tank connection for one PONPC.

You want buffer capacity
need for hydraulic separation, currently as P/S piping
Ability to take heat to load as boiler starts without warming tanks first
Ability to pull from tanks without boiler running

You have all the right components, just some re-shuffling.

In this example, ignore the backup boiler on top, just consider that the loads.
This is what is know as two pipe buffer tank

Boiler is protected from cold return with the mix block
Piping at the tank is the hydraulic separation
one, or multiple load pumps at the tank, a smart zone valve could be adde to give the zones ODR, like the Taco i-valve

More multiple tank piping ideas here

http://www.caleffi.com/sites/default/files/coll_attach_file/idronics_17_na.pdf

 

[grumpy chief]

I'm not sure how much repiping you would be up for, but there are some simpler ways to pipe that system and give it all the functions you want.
Also it would be best to have one expansion tank connection for one PONPC.

You want buffer capacity
need for hydraulic separation, currently as P/S piping
Ability to take heat to load as boiler starts without warming tanks first
Ability to pull from tanks without boiler running

You have all the right components, just some re-shuffling.

In this example, ignore the backup boiler on top, just consider that the loads.
This is what is know as two pipe buffer tank

Boiler is protected from cold return with the mix block
Piping at the tank is the hydraulic separation
one, or multiple load pumps at the tank, a smart zone valve could be adde to give the zones ODR, like the Taco i-valve

More multiple tank piping ideas here

http://www.caleffi.com/sites/default/files/coll_attach_file/idronics_17_na.pdf

I don't see how I could repipe for that schematic with my current setup. Was studying your sticky drawing and saw that you pulled a storage serial loop. Could I achieve the same result by breaking the supply loop between the boiler and mechanical room; adding a set of closely spaced T"s with the yellow jacket pumping into tanks. Could use setpoint option to pull into tanks when temp is high. Three pictures show my situation. Boiler room to left of storage tanks and dug out trench. Mechanical room is in basement below the electrical box on the back side of house. One picture of piping uncovered and waiting to be cut and tied into storage. Closely spaced T setup would work. Also think I could work Maple1's setup into the trench also but feel spaced T's might be easier. Easy to mount the yellow jacket circ in the storage enclosure.
Thanks for the information on the expansion tanks. Would the location above the storage tank be the best. My thinking was most expansion would be at the tanks due to the large quantity of hot water and the largest temp swing.

 

[maple1]

The whole system should see the pressure increase from expansion so it shouldn't matter in that respect where your expansion goes. It is better if it is tied in just upstream from the system circulator (on the inlet side of it). What are you using for expansion? Would also be better to get it as high as you can to max its expansion capability.

I didn't know you were in the middle of trenching - thought this was a fully installed system. But I don't think any of the possible changes I gave to think about would require much serious in the way of re-piping.

Disclaimer repeated - I'm no pro.

And to add - Bob is & knows his stuff.

 

[grumpy chief]

Ok, time to admit my poor decision. Last year I added two 500 gal tanks to the existing 5 year old system. The hot tub sat where the new trench is now. I made a snappy decision to run the lines on the other end of the tanks across to the boiler shed. Probably 60 feet loop. Did not dig deep enough (underground electric service line makes me nervous) and poorly insulated. All winter the snow melted above the newly installed lines. Thought If I had to redo the lines I should put them closer to the existing loop so I dug the new trench to do a tie in. (with proper insulation). Your changes could be done in the trench just a tight fit with no slack to play with.
Using the existing small expansion tank that came with the seton maybe 2 gal capacity. I added a converted 50 gallon water heater as an exp tank when I added the storage. It is at the highest system point in the boiler shed. Two previous trips to Halifax in the winter make me think that if your system works up there you must know enough.

 

[maple1]

If one of those trips was last winter, in February - April, you saw an extreme. Lol. Hope to heck we don't have another one of those - and I snowmobile.

This is a great time to truly make sure your underground is good, and it's the one part that really can impact system perfomance big. Did you read the 'underground' sticky thread? Lotsa good info in there. Or use the Logstor or Thermopex type. Closed cell foam is the important bit.

Good luck, anyway.