Idling

[chuck172]

To make conversion, I'd like to address the ugly term "idle"
Seems like no one here wants their boiler to idle. It's a dirty word. We want to have our boilers running @ 100% to hurry up and burn all the wood in the firebox, and heat our storage.
There are also those who don't have storage for one reason or another and wish they did.
I have 500 gallons storage, considered minimum here in America. I think about norm in Europe.

How wasteful is burning without storage? How much more maintenance is required? Lets face it, 1000 gallons of storage takes up alot of space, is expensive. Tarm, bio-heat, whoever - would like to sell you 4-250 gallon tanks for a small fortune. You can stand up two 500 gallon tanks and make your basement look like a Russian nuclear missile silo. You can put in unpressurized storage with heat exchangers and pray you don't get a leak.

I'd like to double my storage for convenience reasons but the wife flat out says NO. Maybe sometimes we overcomplicate matters. I know I do.

 

[SolarAndWood]

I think storage simplifies my plan. It means no solar required for DHW even in the off season.

 

[sdrobertson]

To make conversion, I'd like to address the ugly term "idle"
Seems like no one here wants their boiler to idle. It's a dirty word. We want to have our boilers running @ 100% to hurry up and burn all the wood in the firebox, and heat our storage.
There are also those who don't have storage for one reason or another and wish they did.
I have 500 gallons storage, considered minimum here in America. I think about norm in Europe.

How wasteful is burning without storage? How much more maintenance is required? Lets face it, 1000 gallons of storage takes up alot of space, is expensive. Tarm, bio-heat, whoever - would like to sell you 4-250 gallon tanks for a small fortune. You can stand up two 500 gallon tanks and make your basement look like a Russian nuclear missile silo. You can put in unpressurized storage with heat exchangers and pray you don't get a leak.

I'd like to double my storage for convenience reasons but the wife flat out says NO. Maybe sometimes we overcomplicate matters. I know I do.

Pretty good observations. I started burning wood with a OWB and I never really cared about how much wood I burnt, I just wanted to load the boiler twice a day and have a warm house. The only reason I would stack up the wood supply was that I would have to listen to the wife "complain" if I left the wood in piles as opposed to nice looking stacks. It had nothing to do with drying as the OWB would still burn the wood even if it was still wet but the smoke output was unacceptable as we live in a small village but with approximately 4 acres of land. Now that I have the EKO it seems that I have gone completely the other direction in how much I care about how much wood I need to burn. During the first year of burning the EKO I had allot of problems with smoke and trying to keep the boiler clean and efficient. All of my problems were directly related to the simple fact that I didn't know as much as I thought I did about drying firewood. If I had tried my first attempt at burning a indoor boiler (EKO) as I burned wood with the OWB without storage I'm sure I would have been complete discouraged and gone back to the OWB because I had to constantly shut down and clean the heat exchanger even though I was never going into a idle. I went with 2000 gallons as I work 12 hour shifts and I didn't want to have to come home after being gone for 14 hours and mess with starting a fire.

Looking back now, I lucked out and made the right decisions on my system. I can get 3 days off the storage during most of the winter when I need to and still have a warm house. I didn't really have a clue as to "btu's needed for x amount of hours" or anything else. I wanted a new polebarn and in this I designed a boiler room and a place for storage. 500 gallon propane tanks are long and slim and I figured that if I had 4 of them I could stand them on end and make a 9 foot square room.

I think that it is much more important to have dry wood for the boiler than storage as to efficiency and ease of maintenance. I've said it before that it should be mandatory that a moisture meter be included with the sale of a boiler. The "it looks dry and it weighs allot less" approach to drying wood was my downfall and it took a borrowed moisture meter to finally get it through my thick head. Storage is simply a battery and it does make life allot easier as to when you need to tend a fire.

 

[willworkforwood]

How wasteful is burning without storage? How much more maintenance is required?

As someone who runs a gasser without storage, idling is an important consideration for me. After going through 2 full seasons, I've come to regard idling as boiler "overload". I'm using overload here to describe the condition where the boiler has been running a bigger fire than is needed for that particular moment in time. This is not to imply that it's possible to avoid idling - boilers without storage are going to idle multiple times per day. The real questions are what's the total idle time, and how can it be reduced. I've been getting better results as time goes on by matching the size of the fire to the current and upcoming conditions (temp and wind). But, this isn't for everyone, and I believe there are some requirements to make it work well. The first one is that the boiler needs to located either be in the basement or an attached boiler room. Those who have boilers located some distance outside, will not appreciate getting dressed and going out in +5 to keep small fires going. The other key item is having someone available (and willing ) to regularly load smaller amounts of wood. My wife is at home while I'm away at work, so there is generally always someone around to load the "right" amount of wood. What's the right amount ? - my best friend in the burning season is the hourly forecast on the web. But, for someone away from the house as sdr describes above, right-sizing the fires just won't work. All you can do is fill to the gills, and take the efficiency hit of much more idling (or use storage to make it work well). Lastly, I agree completely about the importance of properly seasoned wood. Many (most?) of us have learned that it's #1 for gasser efficiency.
So, after this long-winded ramble, I believe the short answer to Chuck's questions about idling is: it all depends. Everyones situation and boiler setup is different and that also means varying degrees of (in)efficiency. I'm ok with not having storage - it's a decent fit with my situation. But I also troll this site, constantly looking for one more thing that might improve my setup - and then another one after that ;-)

 

[chuck172]

My storage is only 500 gallons. I wonder if there is a way to use this minimum amount to my advantage. If I heat the storage up to my 190* temp then load the stove with a pre-determined amount of wood. I would be heating the house and h/w with the boiler and use the storage as a "cushion".
That would really increase the time before reloading. Granted the boiler would idle at times, but like willworkforwood I can vary my load to meet the conditions.

 

[willworkforwood]

I would be heating the house and h/w with the boiler and use the storage as a "cushion".

Perhaps some folks would say that's not the best use of storage. But personally I would LOVE to have 500 gallons of 190* in the bullpen, ready to fix my "mistakes". I can usually figure out the required wood load very close, but of course not 100% of the time. On those occasions where I come up "short", it can take an hour or 2 to get the house back up to temp (sure, I could fire the oil burner, but the sound of it coming on hurts my ears :shut: ).

Chuck, since your better half already cast the deciding vote against more storage, why not go ahead and experiment with what you already own. Who knows - you may find a combination that works better for you. But if nothing good happens, you just go back to how you've run in the past.

 

[chuck172]

Another plus to my idea would be when the storage needs recharging, I would of course burn real hot for aprox. 4 hours at full bore. That would clean the boiler and the pipe of it's previous (idle) cycle.
This technique sure would give me a longer time period between loading.

 

[sdrobertson]

Another plus to my idea would be when the storage needs recharging, I would of course burn real hot for aprox. 4 hours at full bore. That would clean the boiler and the pipe of it's previous (idle) cycle.
This technique sure would give me a longer time period between loading.

I'm not sure if this will really "clean" the boiler out as most of the crud will be in the heat exchanger tubes but it will give you plenty of time to shut down and have time to clean. 500 gallons should be enough to modify your burning schedule some. Sometimes even just 4 to 6 hours helps allot in the real world. Storage really, really helps in the spring and fall where your heat load isn't nearly what it will be in the middle of the winter.

 

[Piker]

My storage is only 500 gallons. I wonder if there is a way to use this minimum amount to my advantage. If I heat the storage up to my 190* temp then load the stove with a pre-determined amount of wood. I would be heating the house and h/w with the boiler and use the storage as a "cushion".
That would really increase the time before reloading. Granted the boiler would idle at times, but like willworkforwood I can vary my load to meet the conditions.

This cushion that you refer to is also known as a buffer. A buffer tank is great for smoothing out the on off cycles of a boiler, and in fact is required on the new Froling pellet boilers for just that reason. You will also find a lot of the new mod-con boilers installed with buffer tanks as well.

No, it's not quite the same as thermal storage, but it's nonetheless an effective tool that you can use to clean up emissions and your heat exchanger a bit.

cheers

 

[tom in maine]

You can put in unpressurized storage with heat exchangers and pray you don't get a leak.

I think this is a possibility with any tank. I would argue that an unpressurized tank is much quicker and simpler to rebuild if the unthinkable does occur.

 

[chuck172]

Piker,
How does a buffer tank differ from a storage tank?

 

[Piker]

Piker,
How does a buffer tank differ from a storage tank?

That's a good question... in fact thermal storage and buffer tanks have some similarities... basically they both consist of a volume of water used to absorb btu's. There are a couple of subtle differences though.

Thermal storage is intended to be as remarked earlier... a battery. Once thermal storage is "charged" the boiler is completely shut down and circulation through the tanks is halted to maintain stratification of the water... unless of course a zone is calling for heat, at which point your battery is discharged to satisfy the heat load. Thermal storage is intended to supply lengthy periods of heat all on it's own... without input from the boiler.

A buffer tank, on the other hand, is generally a much smaller volume of water... perhaps only 50 or 100 gallons on some systems. It is used to create some thermal mass on the system mostly just for the purpose of decreasing short cycling of the boiler - On a gas or oil boiler, this can lengthen the life of the equipment with less on/off cycling... and with wood boilers, it can give you longer periods of good hot combustion followed by a subsequently longer period of idle time... in essence, higher highs, and lower lows. This increases efficiency and helps to keep the boiler perhaps a little cleaner. Buffer tanks are not intended to provide very long periods of usable btu's without input from the boiler... just enough to smooth out the on/off cycling, and circulation is not necessarily stopped through the buffer once the system is up to temperature.

A big 500 gallon buffer tank connected to a boiler with a 20° or 30° on/off differential can make for a pretty efficient non-thermal storage system. For example... once the boiler reaches 185°, it will shut down combustion until it reaches 155. During this time, the buffer can maintain the heat load for "x" number of hours by dispensing 8.3*500*30 = about 125,000 Btu's. The boiler then turns back on to bring the water up from 155 back to 185. This complete cycle might take 4 or 5 hours in a typical home, obviously less if the heat load is higher... but instead of short cycles between on/off, you get long hot burns followed by deep idle time. Long hot burns giving the best combustion efficiency, and deep idle time producing the least woodgas to escape into the atmosphere.

There a a few people I have talked to that use their thermal storage like a buffer in the coldest part of winter... and then like heat storage in the shoulder season. It's important to note that an extremely large buffer that isn't well insulated could end up being more problematic than anything. If too much heat is lost through the piping and tank walls, you just end up burning a lot of wood. Obviously, if the heat is going into the living space, then it's not a big deal unless the living space is being overheated.

hope that wasn't too confusing...

cheers

 

[chuck172]

I can visualize two methods of burning wood with a gasifier and minimum storage :
Method A:
Run boiler to heat storage to 190*
At this time house is using boiler to satisfy zones and dhw providing boiler water temp. is 165* or more, and excess heat is dumped into storage. This usually requires one full load of wood, sometimes adding more wood in cold weather to achieve storage of 190* The boiler does not idle.
Boiler satisfies storage load, runs out of fuel and then house uses 500 gallons of storage.
When storage is depleted (145*) load up boiler and repeat process.
The boiler runs at full bore does not idle.
Method B:
Run boiler to heat storage to 190*
@this time house is using boiler to satisfy zones and dhw providing boiler water temp. is 165* or more, and excess heat is dumped into storage.
Boiler satisfies storage load.
Refill boiler with wood using experience (current weather conditions) to judge how much wood to feed.
Now the boiler will heat the house's requirements, it will idle at times, depending on the house's heating load, storage will be held in reserve to be used when the boiler cools down below 165*.

Seems like method B will greatly increase unattended boiler heating time.

 

[lawandorder]

I also have 500 gals of storage and looked into the price tag of putting in more storage but have decided against it opting instead for working on replacing my traditional baseboard heat with lower temp baseboard or possibly even in floor. Thats what I am contemplating at this point.

 

[woodsmaster]

I can visualize two methods of burning wood with a gasifier and minimum storage :
Method A:
Run boiler to heat storage to 190*
At this time house is using boiler to satisfy zones and dhw providing boiler water temp. is 165* or more, and excess heat is dumped into storage. This usually requires one full load of wood, sometimes adding more wood in cold weather to achieve storage of 190* The boiler does not idle.
Boiler satisfies storage load, runs out of fuel and then house uses 500 gallons of storage.
When storage is depleted (145*) load up boiler and repeat process.
The boiler runs at full bore does not idle.
Method B:
Run boiler to heat storage to 190*
@this time house is using boiler to satisfy zones and dhw providing boiler water temp. is 165* or more, and excess heat is dumped into storage.
Boiler satisfies storage load.
Refill boiler with wood using experience (current weather conditions) to judge how much wood to feed.
Now the boiler will heat the house's requirements, it will idle at times, depending on the house's heating load, storage will be held in reserve to be used when the boiler cools down below 165*.

Seems like method B will greatly increase unattended boiler heating time.

I think that I would only use method b when I needed the extra time away or you will have to clean your boiler more from what I understand.

 

[chuck172]

Every second burn would be at maximum. No idling for 4 hours plus, to recharge the tank. That should help keep down the creosote a bit.

 

[Duetech]

I burned wood in the off season as well as during the "heart of winter" and idled both times. Idling can be modified so you dont' use so much wood. With good dry wood in my EKO40 I would put in about a half load in the afternoon or early evening (summers) then shut the boiler off about bed time (one circ kept running to protect from overheating). The wife and I were gone during the day so after the moring shower routine there was no demand for dhw. Returning from work I would find the boiler temp at around 110-130 and the circ still running. The boiler refractory didn't go through a lot of thermal shock with "cold" boiler start ups either. From the way some have spoken my refractory was in better condition after 4 full years of near non stop running compared to their once-a-day full throttle marathons and seasonal shutdowns. Homeowners Insurance forced me to close down my boiler but it sprung a leak in the bottom seam so it was not a total loss. The boiler paid for itself plus. AND I have a better appreciation of insuratative bureacraticle cohesive influence that has left me with a distinct impression of my lack of enough tar and feathers to share with them. Life goes on. Oh didn't mean to digress... with my 1700sq antiquated farm house I heated with around 7.5 full styled cords per year. summers were usually focused on low btu woods and winters with the premiums btu woods...
I'd do it again witout storage and not blink more'n once or twice though I had storage plans on the table when my plans got changed. Cave2k

 

[goosegunner]

I burned wood in the off season as well as during the "heart of winter" and idled both times. Idling can be modified so you dont' use so much wood. With good dry wood in my EKO40 I would put in about a half load in the afternoon or early evening (summers) then shut the boiler off about bed time (one circ kept running to protect from overheating). The wife and I were gone during the day so after the moring shower routine there was no demand for dhw. Returning from work I would find the boiler temp at around 110-130 and the circ still running. The boiler refractory didn't go through a lot of thermal shock with "cold" boiler start ups either. From the way some have spoken my refractory was in better condition after 4 full years of near non stop running compared to their once-a-day full throttle marathons and seasonal shutdowns. Homeowners Insurance forced me to close down my boiler but it sprung a leak in the bottom seam so it was not a total loss. The boiler paid for itself plus. AND I have a better appreciation of insuratative bureacraticle cohesive influence that has left me with a distinct impression of my lack of enough tar and feathers to share with them. Life goes on. Oh didn't mean to digress... with my 1700sq antiquated farm house I heated with around 7.5 full styled cords per year. summers were usually focused on low btu woods and winters with the premiums btu woods...
I'd do it again witout storage and not blink more'n once or twice though I had storage plans on the table when my plans got changed. Cave2k

Tell us more;

Did the EKO 4o spring a leak after 4 years?

Why did insurance make you shut it down?

gg

 

[Duetech]

Yes the EKO40 (closed system) sprung a leak after 4 years of nearly nonstop running.
Insurance cancelled my policy for no specific reason just general home appearance. But it always came back to the boiler location. The boiler sits there unused and un repaired. Don't know what to do with it.

 

[willworkforwood]

Yes the EKO40 (closed system) sprung a leak after 4 years of nearly nonstop running.
Insurance cancelled my policy for no specific reason just general home appearance. But it always came back to the boiler location. The boiler sits there unused and un repaired. Don't know what to do with it.

All of us who have gone through all of the effort and expense associated with a wood boiler can feel your pain. I would imagine you must have contacted the manufacturer and also perhaps tried getting one or more repair estimates. Can you share any details of where the leak is and how it might have occurred, and the process of trying to get it fixed? Any boiler could potentially leak, and I'm sure most of us are interested :-/ in the specifics, regardless of which make of boiler we own.

 

[Duetech]

Been kind of busy for the last couple of days. sorry for the delay. Boiler leaked in a small straight line about 1 1/4" long, 2 pin holes and one just over 1/8" in diameter and 1/2 again as long. Very bottom on the right when you look at the boiler loading door and about 9" from the front going towards the back. Boiler is still on the steel shipping pallet that it came on so the leak was easy to locate. Comapny I bought if from had a "no sweat" attitude. "It is under warranty get it fixed and we'll send a reimbursement". Guess I couldn't ask for more and I am pleased with their response. (stipulations of a certified welder were a prerequisit and I heartily agrree).
Since the leaks occured in a straight line I think it was a weld seam. (I can't imagine general corrosion eatin through the outer jacket like that in such a specific way). Not disappointed with the boiler. It functioned well and was forgiving enough for my learning curve. Not every manufactured item is perfect. Auto maker recalls are a good example. My woe came from an insurance company that changed its position and my lack of implementing long range plans from the start. If we live past our mistakes hopefully we don't repeat them.
For the above topic of idling and storage dry wood is the bes way to go. I used an air exchange set up that could not tolerate water temps below 140 and work. Trying to use wood above 20% MC is a gunk in process idle or no. This forum has been a great source of info. thanks to all!!