Thermal storage Qs, PEX vs Copper; bleach in non-Pressu. tank; Flue and boiler sizing

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

Bad LP

Minister of Fire
Nov 28, 2014
1,788
Northern Maine
Oh right, i forgot about that part...good thing the father in law is a plumber, he'll catch the stuff i miss.

Does the dump zone have to be gravity feed/below the "water out" from the boiler level?

No, it's above the boiler. Mine is hanging off my floor joists. You use a normally open ZV.
 

Woodman1

Burning Hunk
Jan 15, 2018
138
Michigan
Here are some of my thoughts and observations from operating my EKO 60.

First some facts, my house heat loss averages 24k btu / hour. I have 60 degrees of usable heat from my storage. My boiler and storage are in a separate building.

I would not want anything less than my current 1000 gallons of storage. To heat this 1000 gallons of storage I would not want anything less than my 60. I would not want my eko inside my house due to smoke spillage.

First, the ability to pull 60 degrees from storage is huge. This gives me 20 hours of heat from storage on all but the coldest days. Second, I'm lazy, I'm busy, and I am not around to add wood to a boiler during the day. I get home around 5 o'clock most days. At this point my storage is pretty much depleted. I start a fire in a cold boiler and during that 4 or 5 hour burn the 60 has enough horse power to recharge my storage and heat my house at the same time. Since I set my timer on my boiler I don't have to go back outside (lazy) and I am done for the day.
 

salecker

Minister of Fire
Aug 22, 2010
1,530
Northern Canada
You are going to need a powerless dump zone and that unused fin tube will be perfect for it if you have enough of it.

Unless you have storage,then it becomes the dump zone.
 

maple1

Minister of Fire
Sep 15, 2011
10,809
Nova Scotia
Unless you have storage,then it becomes the dump zone.

It can become a dump zone, but you need to be careful with it. One thing is if you overcharge storage, or it gets close to fully charged, the heat has nowhere to go. But also if you are wanting a no-power dump zone (which should really be part of any system), you also need to make sure you get everything oriented right, and generously size your boiler-storage piping. I thought I had my setup oriented & plumbed right for good convective flow when the boiler circ powers out. Well, it does flow, but I found out in a power outage it wasn't enough flow to handle the boiler output in mid-burn. So was glad I also had a zone to dump to my upstairs rads (which happened to be airlocked at the time), and is also why I also later added a big UPS to plug my boiler circ into. Redundancy is a very good thing when it comes to overheating & dumping.
 

MapleFoxFarm

New Member
Jan 5, 2019
13
vermont
Unless you have storage,then it becomes the dump zone.

Ya, i was wondering if the thermal storage would/could be the dump zone; thanks salecker. So in a power failure or pump failure heat will still make its way/be absorbed by the thermal storage? How does it get there w/o a pump?
 

MapleFoxFarm

New Member
Jan 5, 2019
13
vermont
It can become a dump zone, but you need to be careful with it. One thing is if you overcharge storage, or it gets close to fully charged, the heat has nowhere to go. But also if you are wanting a no-power dump zone (which should really be part of any system), you also need to make sure you get everything oriented right, and generously size your boiler-storage piping. I thought I had my setup oriented & plumbed right for good convective flow when the boiler circ powers out. Well, it does flow, but I found out in a power outage it wasn't enough flow to handle the boiler output in mid-burn. So was glad I also had a zone to dump to my upstairs rads (which happened to be airlocked at the time), and is also why I also later added a big UPS to plug my boiler circ into. Redundancy is a very good thing when it comes to overheating & dumping.

Oops, didn't see your post till just now Maple1. Thank you.
 

Bad LP

Minister of Fire
Nov 28, 2014
1,788
Northern Maine
Unless you have storage,then it becomes the dump zone.

Not something I was willing to try. The dump zone was too easy to build and I'm not sure how it would work with my boiler protection that also has a pump on it.
Powerless works no matter what my tank temps are. I'll think of it being redundancy.

Maple,
With your boiler not having a fan you have nothing to stop the burn. Correct?
In a power outage I'm only w/o it for 20 seconds until the genset fires up and transfers to my generator panel thus turning my fan and pumps back on.
There is always the question... what if the genset doesn't start?
 
Last edited:

maple1

Minister of Fire
Sep 15, 2011
10,809
Nova Scotia
Not something I was willing to try. The dump zone was too easy to build and I'm not sure how it would work with my boiler protection that also has a pump on it.
Powerless works no matter what my tank temps are. I'll think of it being redundancy.

Maple,
With your boiler not having a fan you have nothing to stop the burn. Correct?
In a power outage I'm only w/o it for 20 seconds until the genset fires up and transfers to my generator panel thus turning my fan and pumps back on.
There is always the question... what if the genset doesn't start?

Yes, correct. The thing burns wide open whether it has power or not. If I am there, I can shut the draft up if I have to. Still pumps out some heat for a bit though - so certainly a boiler that loses its air input when the power goes out wouldn't need as much flow as mine when things go dark.

It also heats the house good in a power outage, by convection. But I have to be there & watch close & manually close the damper some & also maybe tweak it on the go so it doesn't get too hot. Small fires for sure in that case.
 

Bad LP

Minister of Fire
Nov 28, 2014
1,788
Northern Maine
Yes, correct. The thing burns wide open whether it has power or not. If I am there, I can shut the draft up if I have to. Still pumps out some heat for a bit though - so certainly a boiler that loses its air input when the power goes out wouldn't need as much flow as mine when things go dark.

It also heats the house good in a power outage, by convection. But I have to be there & watch close & manually close the damper some & also maybe tweak it on the go so it doesn't get too hot. Small fires for sure in that case.

As I figured from your posts.

Great to learn how others are dealing (and sometimes failing) with self engineering.
I learned a bunch here but also saw both good and bad advice. Fact is... I learned. Hate to pass off bad advice costing good people time and $$$. Myself, like others here have good solid trade(s) advice we can all learn from.
 

salecker

Minister of Fire
Aug 22, 2010
1,530
Northern Canada
Ya, i was wondering if the thermal storage would/could be the dump zone; thanks salecker. So in a power failure or pump failure heat will still make its way/be absorbed by the thermal storage? How does it get there w/o a pump?
Maple1 made a few points.
My storage is my dump zone,works good we have had a few outages where i had just filled the boiler.Heat went into storage.
As to having the room for BTU's in storage...
With my controls on my boiler the highest i can get storage to is in the 180'sF I know roughly how much wood to burn to get to my max temps.Even them there is still room for more BTU's should there be any.If i know that i am 1/2 load away from max temp i will not load a full load.If someone is running their system and knows it i cannot see how they could ever need a dump zone with storage.
My boiler dosn't run wide open when there is no power.Not sure that there actually many gasification boilers the would run wide open,because most have a fan to provide combustion air,no power no fan.So depending on your choice of boilers.... i still don't see a need for a dumpzone while having storage.
 

Fred61

Minister of Fire
Nov 26, 2008
2,444
Southeastern Vt.
I can visualize thermo syphoning in a pressurized system where storage is just an extension of the boiler water jacket. With an unpressurized setup you will be heating the "bath" either with the existing coils or as I did with a plate heat exchanger. The added hardware between the boiler and storage could gum up the gravity flow. A 200 foot coil could also slow or resist flow.
 

maple1

Minister of Fire
Sep 15, 2011
10,809
Nova Scotia
Yes, pretty sure it wouldn't work very well with open storage. Also if the storage & boiler were very far apart at all, that would hinder.

Mine are right next to each other, but there are some piping bends and some horizontal piping in between and the storage isn't a whole lot higher than top of my boiler. Also not sure how much the loading unit holds flow up. Literature indicates not much but likely it does a little bit. If I had gotten my storage as high as I could, made more direct connections to the tanks, and oversized that piping, it would have improved it a lot.
 

BoiledOver

Minister of Fire
Apr 14, 2013
620
43°58'55 N - 85°20' W
Fred, thanks (again),
I say, 'again' because we actually talked through craigslist about your set up several weeks back! My name is Trevor from near Montpelier. I would really love to buy your system but as we discussed, i can't get that tank into my basement and it sounds like a lot of folks are saying don't put your thermal storage in an out building bc of heat loss. Thanks for all the real world operating specifics on the EKO 25. Much appreciated.
Hello MapleFoxFarm welcome to the boiler room. You've already received most pertinent info concerning your plans. The flue size has been discussed so I will just add what I had done before the install. Cut a round plate to fit the boilers flue exit size and welded in place, then cut a 6" hole in that to begin the flue piping. Adapters and reducers will accomplish the same result but I chose to keep it short.

In my opinion, you might want to rethink Fred's system. The only thing you would need to supply is a new storage vessel to fit the exchange coil which is a proven component. Some folks purchase kits and others do their own MacGyvering. A 10 year Eko boiler is not near its end of life. Components are still available from Zenon at New Horizon and any leaks to the water jackets are welder repairable. I have backup components for my particular setup on a shelf ready for installation when/if the need arises (boiler controller, blower assembly, circs and aquastats). A member here had purchased two units way back when, not Eko and didn't install the backup until just a few years ago. I'm thinking it sat in his barn for a couple decades until needed.
 

MapleFoxFarm

New Member
Jan 5, 2019
13
vermont
Hello MapleFoxFarm welcome to the boiler room. You've already received most pertinent info concerning your plans. The flue size has been discussed so I will just add what I had done before the install. Cut a round plate to fit the boilers flue exit size and welded in place, then cut a 6" hole in that to begin the flue piping. Adapters and reducers will accomplish the same result but I chose to keep it short.

In my opinion, you might want to rethink Fred's system. The only thing you would need to supply is a new storage vessel to fit the exchange coil which is a proven component. Some folks purchase kits and others do their own MacGyvering. A 10 year Eko boiler is not near its end of life. Components are still available from Zenon at New Horizon and any leaks to the water jackets are welder repairable. I have backup components for my particular setup on a shelf ready for installation when/if the need arises (boiler controller, blower assembly, circs and aquastats). A member here had purchased two units way back when, not Eko and didn't install the backup until just a few years ago. I'm thinking it sat in his barn for a couple decades until needed.

Thanks for the advice BoiledOver! I hear you on Fred's setup but back when Fred bought his setup those EKOs were a lot more expensive. I can get a new 25 for about $3,600 + $400 shipping. New 3/4" coil 200' is about $1400, and a 200k btu heat exchanger is around $350, however, I'm probably going use an old radiator unit as the change 'coil'. So w/o new copper it'll cost my ~$4,350 + home made tank.Plus I'm running this in parallel with a propane boiler so I don't need new circulators.
Are there other components to the boiler itself that Fred's has that I would have to buy if i went with new? Like some sort of controllers or something? Again, I would love to help Fred out but the numbers as i understand them don't quite tip the scales in Fred's favor (for me). But again, I'm clearly new at this, so there might be something I'm missing.

On another note, are you running radiant, bb or something else from your 25 w/1000 gal storage?
Im running baseboard so i was curious what your burn schedule was and if you had a hard time with getting an average of 180 F for bb heating (if that's what you have)?

thanks !
 

maple1

Minister of Fire
Sep 15, 2011
10,809
Nova Scotia
Your emitters needing an average of 180 doesn't match up with using storage.

The whole point of storage is burning wide open until storage is charged, the coasting off storage until you need heat again. Which means storage supplied temps would range from (say) 180, down to the minimum you need to keep warm. In my case, thats 130-140. Or so. If your emitters need water that hot, you will be burning more often, which likely means idling and all that comes with not having storage.

I also have baseboard, but it is oversized for my heat loss.
 

Woodman1

Burning Hunk
Jan 15, 2018
138
Michigan
I agree with maple. If you really need an average of 180 water I see very little benefit of storage for you. I also think you will have a hard time getting your storage up to 180 with your described heat exchangers. I would think an average of 10 degrees less at each exchange point. So a 180 degree eko might get you 160 degree water to your bb. It seems to me you would be better off just running without storage and see how it goes
 

Fred61

Minister of Fire
Nov 26, 2008
2,444
Southeastern Vt.
I was able to get my storage above 180 but I seldom did because there was not a need to. Those last few degrees come at a cost. But I cheated to achieve it. What I did was incorporate a Techmar 156 in place of the original sensor for the boiler and through hit and miss bury the original sensor into the insulation which would allow the boiler to get to 200 degrees before overheat shutdown. Being a D/T control, the Techmar was then in control. So one sensor in the boiler and the second one in the well in the center of the tank gave me all kinds of flexibility and I was able to monitor the boiler temperature from the readout screen of the Techmar.
 

MapleFoxFarm

New Member
Jan 5, 2019
13
vermont
Your emitters needing an average of 180 doesn't match up with using storage.

The whole point of storage is burning wide open until storage is charged, the coasting off storage until you need heat again. Which means storage supplied temps would range from (say) 180, down to the minimum you need to keep warm. In my case, thats 130-140. Or so. If your emitters need water that hot, you will be burning more often, which likely means idling and all that comes with not having storage.

I also have baseboard, but it is oversized for my heat loss.

Hi again Maple1, thanks for all your input on this thread.
I do see the advantage of storage and how you coast off the stored heat in the water after burning "wide open" which is good for efficiency (no idling, less creosote, less ash). I believe it was you and i that were talking a few days back about a boiler being able to "keep up" as i put it, and this is what I was referring to. If I need ave 180 F water to circulate through my BB, will i be able to have enough of that temperature water in my storage tank to satisfy house heating requirements? I think you answered that just now by saying i would have to fire more often but I wanted to incorporate thermal storage to avoid having to fire more than twice a day. Am I up the creek?

Now, the impression I'm operating under is that i need ave 180 F water for BB because i feel like folks have been saying that. Is this not the case? I also think i heard/read that you can increase your finpipe/radiator amount to radiate more heat at lower water temps? Is that true?

I have been reading up on plumbing stuff at this site and page:
https://www.pmmag.com/articles/9985...e-heating-and-repurposed-thermal-storage-tank

Is this a good source of info or would you recommend somewhere else?

Thanks for your time Maple1!
 

Bad LP

Minister of Fire
Nov 28, 2014
1,788
Northern Maine
You must either add more BB fin tube to offset the lack of 180 water or change your BB to panel rads. Having a two story house with only two zones tells me that panels won't work but that's just a wild ass guess on my part. Like I said earlier at some point I will add panels in at least the master bedroom and loft (that barely runs) and either a CI or more panels in "Man Town" that currently is closed off in the winters unless we have a house full of snowmobile guests for the weekend. Man Town is not a priority now because we don't live there full time yet.
 

maple1

Minister of Fire
Sep 15, 2011
10,809
Nova Scotia
If I need ave 180 F water to circulate through my BB, will i be able to have enough of that temperature water in my storage tank to satisfy house heating requirements?

As you heat from storage, the temperature of it will decrease over time. So how far you can go with that depends what your heating requirements are.

Now, the impression I'm operating under is that i need ave 180 F water for BB because i feel like folks have been saying that. Is this not the case?

Again, depends totally on your heating requirements and how the heating system was sized to the house. If professionally done, they would for example design how much baseboard to install based on a certain supply temperature.

I also think i heard/read that you can increase your finpipe/radiator amount to radiate more heat at lower water temps? Is that true?


Yes, basically speaking. The ease of doing so would depend on your particular baseboard install situation.

You should be able to get half an idea how you are sitting with respect to all that by observing how your existing system heats your house with certain supply temps.
 

Bad LP

Minister of Fire
Nov 28, 2014
1,788
Northern Maine

I also think i heard/read that you can increase your finpipe/radiator amount to radiate more heat at lower water temps? Is that true?


Yes, basically speaking. The ease of doing so would depend on your particular baseboard install situation.

You should be able to get half an idea how you are sitting with respect to all that by observing how your existing system heats your house with certain supply temps.


To expand on the above you could turn your current boiler limits down to say 135-150 (L-H) and see how your home performs. Don't go lower than 135 or you may have issues with condensation.