First Steps in Planning Water Storage

[RDabate]

Hi,

I'm using an EKO 25, this is the first year and so far it works pretty well, but I need it to work more efficiently. I hate waking up at 6:00AM to find my fire is out. I load the dam thing like 3 to 4 times a day. From what I understand, with storage, it will increase the efficiency of how this whole thing works. I was wondering, where to people go to find a storage tank? My boiler is located in the basement; I do not have a walk in basement, only a bulk head. So I'm worried that I'm not going to be able to get a big enough tank down there. And someone point me in the right direction?

Rick

 

[Bad Wolf]

Funny you should ask that question. I constructed an unpressurized system for use with my Tarm, and have been trying to unload, er sell the extra materials.

Seriously, one option for storage is an unpressurized system. A lot of people either buy them ready made from STSS or fabricate their own. I built a 1200 gallon system that I think works pretty well. It consists of a cut down swimming pool and an EPDM liner. See my listing under the for sale forum. I'm down in Colchester and would be glad to give you tips and point out my mistakes.


Greg H

 

[stee6043]

I have to tell you - when it get's really cold (below zero) you're going to be loading your boiler in the morning whether you have storage or not. We had one heck of a cold snap in January. For the days we had highs of five above and lows of fifteen below zero I was loading my EKO 40 when I got home from work at 5pm, again at 9pm, I'd set my alarm for 1am to load it and then I'd throw one more load in at 5:30am before I left for work. In all of this burning I was barely accumulating enough heat in my 1000 gallons of storage to take me through the work day.

All of that being said - on days when it's 20 or so outside, maybe a little sun, I operate all day on a fire started at 5pm and reloaded one time at 9pm. So on these days storage is absolutely GREAT.

FWIW, buying tanks can be a challenge. If you don't have easy access to your basement you may want to look into non-pressurized open tanks that can basically be built-in-place.

 

[Nofossil]

I have to tell you - when it get's really cold (below zero) you're going to be loading your boiler in the morning whether you have storage or not. We had one heck of a cold snap in January. For the days we had highs of five above and lows of fifteen below zero I was loading my EKO 40 when I got home from work at 5pm, again at 9pm, I'd set my alarm for 1am to load it and then I'd throw one more load in at 5:30am before I left for work. In all of this burning I was barely accumulating enough heat in my 1000 gallons of storage to take me through the work day.

All of that being said - on days when it's 20 or so outside, maybe a little sun, I operate all day on a fire started at 5pm and reloaded one time at 9pm. So on these days storage is absolutely GREAT.

FWIW, buying tanks can be a challenge. If you don't have easy access to your basement you may want to look into non-pressurized open tanks that can basically be built-in-place.

Please allow me to respectfully disagree about morning loading. As long as your heat load isn't too high and you have adequate storage, it's quite possible to load only in the evenings. I have loaded my boiler on exactly two mornings this season, in both cases because I was away the previous evening and couldn't get a long enough fire to charge storage.

On a really cold day I'll start my fire late afternoon (maybe 4:00 or 5:00) and load it three more times, the last being 10:30 or so, when I pack it as full as I can of the densest wood that I have. That will carry me until the next evening.

Most days, I'll build around 7:00 or 8:00, refill it in an hour, then refill it when I go to bed. On average, I need 7 hours of burn time per day and a load will burn 3 or 4 hours.

My boiler puts out around 60,000 BTU/hr, and my peak heat load is an average of 30,000 BTU/hr on the coldest days.

 

[Fred61]

Superman,

You will definately get better efficiency with storage but you won't see the improvement of others who's boilers idle for a longer time, will see. Loading that many times a day indicates to me that she's not idling much. You will see a huge improvement in efficiency in the shoulder seasons i.e. early winter - late winter.

 

[hoth2oguy]

as several folks here have indicated storage does NOT increase the output of your boiler, so on colder days you will have to load the boiler just as often. Storage really starts to sing on days when it is not so cold. I would suggest that nofossil is able to fire/load infrequently because his heat load is pretty small. My guess is that with a 2800 foot colonial yours is about twice his. This means that when you are firing the boiler on a cold day all of the heat generated is going straight into the house and there is little 'left over' heat for putting into storage. Don't get me wrong, storage is still the way to go and you won't regret it once you have it, but I don't want you to think it is going to help out much on the coldest days of the year. Good news is because your boiler is working hard and not idling as Fred61 points out, you are not building up excess creosote and condensation and shortening the life of your boiler.

As far as sourcing a tank, you can save a lot of money if you build your own and there is a lot of good advice here about how to do that. BioHeatUSA sells both pressurized and un-pressurized tanks and I believe AHS sells pressurized tanks if you are looking for an off the shelf solution. Good luck!

 

[cguida]

Hi Superman,

Here is a thread that illustrateds my experience with tank-building -- about 1000 gallons SSTS-style, unpressureized; flat plate heat exchanger. Cost for the tank itelf was about $600. Heat exchanger and pump was another 400, so say about a thousand bucks total. We are very happy with it. My wife no longer makes comments about the 'Think Tank,' or "The-Tank-That-Talk-Built."

https://www.hearth.com/talk/threads/30706/

If you get some kind of storage going, you'll really like it -- especially when the weather softens up.

Regards,
Smee

 

[pybyr]

My wife no longer makes comments about the 'Think Tank,' or "The-Tank-That-Talk-Built."
Smee

Wives, girlfriends, Bah Humbug... my boiler keeps me warmer than most I've been around (although in truth, I am sincerely hoping to eventually meet one who is right for me)

 

[stee6043]

I have to tell you - when it get's really cold (below zero) you're going to be loading your boiler in the morning whether you have storage or not. We had one heck of a cold snap in January. For the days we had highs of five above and lows of fifteen below zero I was loading my EKO 40 when I got home from work at 5pm, again at 9pm, I'd set my alarm for 1am to load it and then I'd throw one more load in at 5:30am before I left for work. In all of this burning I was barely accumulating enough heat in my 1000 gallons of storage to take me through the work day.

All of that being said - on days when it's 20 or so outside, maybe a little sun, I operate all day on a fire started at 5pm and reloaded one time at 9pm. So on these days storage is absolutely GREAT.

FWIW, buying tanks can be a challenge. If you don't have easy access to your basement you may want to look into non-pressurized open tanks that can basically be built-in-place.

Please allow me to respectfully disagree about morning loading. As long as your heat load isn't too high and you have adequate storage, it's quite possible to load only in the evenings. I have loaded my boiler on exactly two mornings this season, in both cases because I was away the previous evening and couldn't get a long enough fire to charge storage.

On a really cold day I'll start my fire late afternoon (maybe 4:00 or 5:00) and load it three more times, the last being 10:30 or so, when I pack it as full as I can of the densest wood that I have. That will carry me until the next evening.

Most days, I'll build around 7:00 or 8:00, refill it in an hour, then refill it when I go to bed. On average, I need 7 hours of burn time per day and a load will burn 3 or 4 hours.

My boiler puts out around 60,000 BTU/hr, and my peak heat load is an average of 30,000 BTU/hr on the coldest days.

I should have qualified my statement with some stat's I suppose. I heat 3200 sq. feet with a water-to-air HX. In the math I've done based on my change in tank temps during they day I can push 60-70,000+ btu/hr heat loss when the temps are five and ten below zero (keeping it at 70 inside). I have a tremendous amount of windows but a 2003 built home. So there you have it. For me, on those wicked cold days, I can't physically stuff enough hardwood into my EKO 40 to avoid morning loadings. In January I probably had less than five morning loadings total, FWIW...

But again, here we are on Saturday and in West Michigan it's 44 degrees. I may not burn at all today. My tanks are 160 plus and life is good....

 

[pybyr]

I heat 3200 sq. feet with a water-to-air HX. In the math I've done based on my change in tank temps during they day I can push 60-70,000+ btu/hr heat loss when the temps are five and ten below zero (keeping it at 70 inside).

Stee- your set up is similar to mine, except that I'll have unpressurized storage with the water-to-air HX.

Can I ask you what you are finding in terms of how cool the water from your storage can get and still give you some useful heat output from the water-air HX?

Thanks

 

[stee6043]

I heat 3200 sq. feet with a water-to-air HX. In the math I've done based on my change in tank temps during they day I can push 60-70,000+ btu/hr heat loss when the temps are five and ten below zero (keeping it at 70 inside).

Stee- your set up is similar to mine, except that I'll have unpressurized storage with the water-to-air HX.

Can I ask you what you are finding in terms of how cool the water from your storage can get and still give you some useful heat output from the water-air HX?

Thanks

I've learned a lot in terms of "useful heat". First and foremost the addition of a 3 speed pump on my HX loop was a huge improvement for me. I've really had a much better time dialing in my system with the ability to adjust flow without using my ball valves and a dimmer switch.

For me anything above 160 in the tanks is "great". I get good heat through the house without the furnace blower running "too much". On most days (anything above 15 degrees or so) I can still do a pretty good job heating the house with 140-160 degree water without excessive furnace blower on-time. Anything below 140 for me starts to get shady. If it's sunny and 30 outside, no problem. But if it's cold and cloudy or nighttime my furnace blower will run almost non-stop when water temps are in the 130's and below. Since furnace blower = electricity I've been trying to do my best to time loadings and adjust flow to avoid dropping my tanks below 140. Some days it can't be avoided but most days I do pretty well...

 

[Piker]

Superman,

You will definately get better efficiency with storage but you won't see the improvement of others who's boilers idle for a longer time, will see. Loading that many times a day indicates to me that she's not idling much. You will see a huge improvement in efficiency in the shoulder seasons i.e. early winter - late winter.

I think this is key. If you're boiler is not idling, you don't have any excess Btu's to spare for storage, and thus may actually have a more difficult time with maintaining fire if you add storage.

One thing to check... if your boiler is sized properly, and your not idling at all, make sure your wood has a fairly low moisture content. 25% or below. Several of my customers have gotten into situations where their wood was much much less than optimal, and their boilers had to run flat out all the time just to keep up with demand... as soon as i brought them some decent dry hardwood, their boiler output increased drastically, and allowed for longer burn times and the idling that is necessary to get 8 and 10 hour burn times.

As a rule, I think it's a good idea to double the size of the boiler needed to heat just the house alone when you add thermal storage. So if your heat loss calcs come in at 75,000 Btu/hr then I would want a boiler with 150,000 Btu/hr output. Remember, solid fuel boilers do not have static output... a little over head when necessary can be beneficial. The smaller the boiler you have, the longer you will have to keep it fired to get your storage charged, and the less storage you will actually need. That's fine, but you may find yourself going to bed at night knowing that your storage won't be up to temp by the time the wood in the firebox runs out. As you increase the size of your boiler, the amount of time it takes to charge your tanks decreases, and thus will require more thermal storage to get you to your next filling. What you first have to figure out is how often do you actually want to fill the stove, and then reverse engineer everything from there.

Storage IS very beneficial. Think about it... at some point in the season, regardless of what size boiler you buy, it will be oversized. To fire your boiler once every two days or so in the shoulder seasons is definitely bliss.

cheers

 

[timberr]

Hey Superman,

I have a Eko 25 w/ 500 gal. of storage. I do 2 burns to heat the house, DHW, and Hot tub. If the lows are in the teens I get away with 2 burns, when then temps bottom out below 0 I need to add wood during the night. I have added a DC power inverter so in my AM burn I can "load" the boiler. Storage is good but if you let it get too cold it is a groan to get back "ahead" of. I too only had a bulk head to get my 500 gal. propane tank into, i needed to take out and inner door to make it fit but no big deal. Personally I liked the pressurized storage option, it is more compact and I felt the long-term maintenance was going to be less.

Good luck

 

[Piker]

Just a quick note, like timberr said... if your storage temp drops to a point where your radiation can't keep up with the heat load of the house, you will be going much longer without heat while your boiler catches up. This is another reason why I don't have a problem with folks getting a boiler with a little bit of overhead.

cheers

 

[Fred61]

Superman,
Going back to your original post. I see you are heating a 2800 sq. ft. home built in 2003. I don't know your heat loss nor what you are burning for wood, but I do know that if your wood is good hardwood and at a reasonable moisture content, you are putting out a hell of alot of heat. A home built in 2003 should have been built to the most recent energy standards and, in my opinion should heat quite easily. I think you should have storage but I would start looking elsewhere to find where all that heat is being lost or whether you boiler is making the most efficient use of the fuel you are feeding it.

 

[Piker]

My first suspicion is always the wood.

cheers

 

[sweetheat]

superman: With thermal storage you life will be much easier. For example my last fire was Saturday afternoon. My storage tank temps were 175, Sunday was 45 degrees here so of course I did not have to fire the boiler. I'll check my storage tank temps this morning, I should see 110 or 120. It might make it through the day but if I have time I will fire this A.M. or I could go all day without a fire if it warms up a bit more. Good insulation + dry wood+ 806 gallon of storage + radiant slab = less wood consumption, a warm shop, and clean burns. Sweetheat

 

[RDabate]

WOW, you guys are great! Lots of information. I've been kind of busy, expecting a second baby boy next month.

I guess I don't know where to start when trying to make this thing the most efficient. I haven't really changed any settings on it. I don't have a moisture meter to test the wood yet. And have not adjusted the secondary fans because I can't get the panel off. The screws are too tight and I don't want to strip it. The people I bought it from where supposed to help me but have proven to be useless. I keep the controller set at 180.

I'm not sure yet what I'm going to do with storage yet. All I know is that I don't want a giant pool in my basement. I'd like something as compact as possible.

Just a few random questions while I'm here.

When you guys say, "I do about two burns a day", do you mean your loading wood twice a day.
If the EKO is on Idle, does that mean I should not hear the fan running?
Also, this is the first year and everything is new. There is already A TON of ash and sut in the vents / ductwork that goes out to the chimney. Is this normal?
How often (if at all do you have the chimney cleaned out?).
When loading wood, (Sometimes my duct work gets so hott ,it will sizzle if I spit on it. Is that normal?

 

[Piker]

if you have creosote in your chimney with the boiler running full tilt to keep up... your wood is too green.

Check the wood first, or get some stuff that you KNOW for sure is dry and see what happens.

cheers

 

[stee6043]

For me "two burns a day" means a cold start with a full load of wood (at 5pm) and then a refill at 9pm. That's it for a "normal weekday". Weekends I burn more since I keep it warmer for longer and I like to get my tanks back up to full temp.

If your EKO is idling the fan should not be running except for the breif "puff" every few minutes....

 

[RDabate]

Since this is my first year, I'm not in control of the wood I have. I had to buy it from someone I know who sells it. Good deal by the way, 180 a cord. Or a least I think that's a good deal. Anyway, I first bought 3 cords from him in the fall........that batch seemed very dry. Since then I got two cords in the middle of winter, this wood didn't seem as dry as the first batch. I'm on my 5th cord for the year. I've seen it idel at times, but mostly, the fan is on.

 

[Piker]

5 cord seems like a lot for 2800 sq feet at this point in the season.

Without seeing your heat loss calcs and your install... my first guess is still the wood. My experience has shown that if everything else is "right," ie installation, boiler adjusted properly, boiler not undersized, boiler is free of excessive amounts of ash in the firebox and combustion chamber, smoke stack is not plugged with ash, etc etc... the wood is almost always the cause of most folks' troubles.

 

[RDabate]

As far if this is installed correctly, to be honest, I was at the mercy of the company I bought it from and the person they recommended to install it. I made a bunch of calls and nobody understands this stuff. The guy installing it was pretty good, but this was his first one. I'm not exactly "HVAC" inclined so I feel like I'm kind of screwed and on my own unless I can find someone local to me that can take a look at it who actually knows what there talking about.

 

[Piker]

To be sure, there is much more science involved in hydronic heat than most people know or even care to know. Now, I don't consider myself to be even close to being an expert at all this... I have an engineer who assists me with the more complex systems... but when I start talking hydronics to customers, ie thermal storage capacity, flow rates, head loss, heat loss, etc etc... folks tend to give me the deer in the headlight look. While these are definitely a "thinking man's heat system," I feel it's not necessary for the customer to understand 100% of the mechanics of their system... as long as I do, there shouldn't be any problems that we can't solve with good communication. If you had someone install your system that was new to the gassers, there might be issues... there might not be... I would still check the wood before I got my knickers all in a bunch.

Just be patient, and you will get this figured out. Start with the wood and go from there. It has alot more to do with performance than most people realize.

cheers

 

[Medman]

I am also running the EKO 25 for the first year. I am burning known dry wood, and I also have a lot of flyash buildup in the flue/chimney pipe. I have had to clean this out every few weeks, but it is simply a matter of dropping the bottom plug out of the tee I installed on the back of the EKO and using a shop vac (boiler fire out) to clean it. The rest of the chimney is clean. I think your wood usage is definitely due to the wood being too wet. I have 2500 sqft and DHW and I am seeing a lot of idle time with the boiler. Temp set at 180* during the cold weather, 175* during this mild spell. I have burned 3 full cords since Nov. 20, and I expect to burn about 1 more for the season.