# EKO or Econoburn?



## Father John (Dec 13, 2007)

I would greatly value an opinion on the merits/need of water storage. Our monastery will be installing a wood gasifier to heat our hydronic radiant floors, and have been looking most seriously at EKO and the Econoburn. The importer for the EKO very kindly explained why a storage tank was so valuable, and it made great sense to me. The people at Econoburn kindly explained why a storage tank wasn't needed really, and that also seemed reasonable.

Is the technology that different between the two boilers or is something else at play here?

Many thanks for the help.


----------



## Grover59 (Dec 13, 2007)

I am at this time building a storage tank, I ran last year without it, and I was fine I have a Black Bear Boiler which works much like what you are considering. I want the storage because it will allow me to be more flexable as to when I have to stoke the boiler. In my opinion the tank would work great with radiant floor heat because you can bring the temp of the tank down lower and still get usable energy from it. If you seach here in this forum you will find many threads and comments on why or whynot a storage tank.

Steve


----------



## Eric Johnson (Dec 13, 2007)

Welcome to Hearth.com and the Boiler Room, Father John. I'm glad to hear that your monastery is serious about wood heat and wood gasification.

I think gasifiers and hot water storage tanks are made for each other, especially in a warmer climate like you're likely to see in southwestern Virginia.

The reason you want storage if you can afford it is that modern gasifiers such as the EKO, Econoburn and Tarm run most efficiently and cleanest when going full-bore. So if you can run them at the optimum level in any weather, and stash any heat that you don't use immediately into the tank for recovery later, you're going to use less wood, create little-to-no smoke and extend the life of your boiler. Think of the hot water storage tank as a battery.

In my opinion, the reason manufacturers and dealers tend to downplay the need for a tank is that most customers have enough trouble getting over the sticker shock of the boiler and installation cost alone, and it's hard to make the case for spending half again as much for a tank. I think they assume, rightly so, that once you get the boiler and realize the potential of the tank, you'll add it later. And that's not an unreasonable approach. I don't have my tank working yet, so I'm running my EKO without it, and it works great. It will be even better with a tank, but it's not absolutely necessary. I look at the tank like cruise control and air conditioning in a car: You don't need it to get from Point A to Point B, but it sure makes those long summer drives a lot more bearable.

So, you were getting an accurate answer from both people. There are no fundamental differences between those two boilers that I'm aware of. It's just a different sales approach, IMO.

As Maine says, there's a lot of discussion of the relative merits of storage tanks in this forum, both from people who are using them, and those who are not. I don't think we have any Econoburn users onboard yet (one dealer, who may be using one), but it's just a matter of time. Plenty of EKO and Tarm owners, too, plus a number of other brands you might be interested in learning about.


----------



## Nofossil (Dec 13, 2007)

I'll echo the comments by Maine and Eric. I'll also suggest that there's more planning and engineering involved in sizing and setting up a storage tank and the associated heat exchangers. Again, lots of discussions in other threads. It's something where it may be difficult to find anyone in your area with the experience to do it for you, so dealers may fear that suggesting it might scare you away.

It's worth doing a heat loss study and determining both peak and average heat loads. From that, you can determine how long a tank of a given size could heat your building. Tanks are great, but too small a tank may not be worth the aggravation.


----------



## kuribo (Dec 13, 2007)

Nofossil-

could you tell me what your heat loss is at your design point, and what outside temp you are using for your design point? Thanks....


----------



## Father John (Dec 13, 2007)

Eric, thank you very much for the explanation of the dealer's attitude about storage. I am trying to determine storage type and size right now, since we will be using some of the aerated concrete blocks left over from the monastery construction to build a boiler/wood storage room off the end of the garage. I am wondering if the aerated concrete (because of its thermal mass inertia) would be a suitable material to use for a tank, or would epdm lined plywood be better?

Also, is a flat plate hx suitable for a 1000 gals tied to an EKO 80, or are copper coils/loops required?

Thanks again for the valuable opinions.

Father John


----------



## Father John (Dec 13, 2007)

Sorry to ask a well worn question. I have only just found the discussion about cinder block walls and swimming pools for tank material.

Although our total area is over 11,000 sq. ft., our total panel output is 228,255 Btu/h, and the total panel back loss is 48,347 Btu/h. There are 14 zones in the building, each zone with its own manifold, circulator, circuit setter for flow control and attached to the boiler loop with 2 Grundfos injection mixing pumps (that is, half the zones on each injection system). The system was ably designed by Embassy Industries, but installed by us, so not a professional installation. Everything seems to work as planned though.

I am curious to know exactly what info I will need to measure to size the storage tank and determine type/size of hx?

As far as average loads go, the system currently has 2 Burnham V84 oil boilers attached, each rated I think at 144,000 Btus. Since our design temps were 0 degrees outside and 70 inside, we have never run more than one boiler at a time. We planned to put in the wood fired main boiler when construction was over, but with oil prices what they are I think time spent in the woods is more than justified now.


----------



## Eric Johnson (Dec 13, 2007)

Beautiful setup, Father John. I'll wait for the heating pros to comment on the specifics, but methinks you will want more than 1,000 gallons of storage if you can swing it. We also have one member, leaddog, who is running an EKO 80. Hopefully he will provide some insight, too.

As to a flat plate vs. copper, copper is the tried and true, but I think an external hx like a flat plate has potential. But there are basic differences between the two approaches that you need to consider, probably with the help of someone with a lot more experience than I have. The good news is that you size the hx to the size of your boiler, not your tank, so a bigger tank does not mean more expensive copper or a bigger flat plate.


----------



## Nofossil (Dec 13, 2007)

kuribo said:
			
		

> Nofossil-
> 
> could you tell me what your heat loss is at your design point, and what outside temp you are using for your design point? Thanks....



My design is based on a peak heat loss of 30,000 BTU/hr at -20 degrees. Seems about right based on actual experience.


----------



## Nofossil (Dec 13, 2007)

Father John said:
			
		

> Sorry to ask a well worn question. I have only just found the discussion about cinder block walls and swimming pools for tank material.
> 
> Although our total area is over 11,000 sq. ft., our total panel output is 228,255 Btu/h, and the total panel back loss is 48,347 Btu/h. There are 14 zones in the building, each zone with its own manifold, circulator, circuit setter for flow control and attached to the boiler loop with 2 Grundfos injection mixing pumps (that is, half the zones on each injection system). The system was ably designed by Embassy Industries, but installed by us, so not a professional installation. Everything seems to work as planned though.
> 
> ...



You can come and do plumbing here anytime - that looks great.

Since you can get by with only one burner, your peak load must be less than 144,000 BTU/hr. Based on the size, it may not be much less, though. In sizing a tank, consider how long you'd like to wait between fires. A day would be a reasonable minimum. Water takes 1 BTU to raise the temperature by 1 degree. Water weighs 8 lbs/gallon so a 1000 gallon tank weighs 8000 lbs, and will absorb and return 8000 btu per degree. If you assume that the tank can be heated to an average temp of 160 degrees, and that you can extract usable heat down to 90 degrees, that's 560,000 BTU of usable storage. At a peak load of 100,000 BTU (just a back-of-the-envelope number for illustration) you could go 5 or six hours between fires at the coldest time of the year with a 1000 gallon tank.

You'll want to estimate your average heat load (you can do that by looking at your monthly oil bills) and work up an actual estimate. My gut says 1000 gallons might be a bit small, but its a tradeoff. 

Hope this helps.


----------



## pbvermont (Dec 13, 2007)

My understanding of the size of heat storage tanks is: the bigger, the better.  Of course the major limiting factors are construction materials, methods and the space you have to allocate to the tank.  
   By the way, when calculating BTU storage capacities of tanks, use the figure of water weighing 8.3122 @ 77degrees F.  Not to be nerdy about it,  but when discussing a thousand gallons of water or more, that .3 makes a difference in your calculations.


----------



## Father John (Dec 14, 2007)

From what I heard today it seems that Econoburn has just committed to STSS to sell their tanks when storage is needed in future installations. This seems odd in light of what Econoburn told me just a day ago, about storage being needed by other boiler designs, but not by them.

Econoburn did say they thought the EKO was not very heavily built, in comparison to their boiler, but I just got the shipping weight of the EKO 80 - 2380 lbs on steel pallet, incl. wooden crate - which sounds pretty heavy to me. At only 65% of the cost of the Econoburn, is the EKO too good to be true? Are there any hidden problems with the EKO?


----------



## Eric Johnson (Dec 14, 2007)

I think they're both good boilers. EKO is made by Orlan, which as I understand it, is a well-established and respected boilermaker in Europe. Econoburn is manufactured in the U.S. by an established and respected boilermaker, even though the wood-burning line of boilers (Econoburn) has only been on the market for around a year, I believe. Having never seen an Econoburn, I can't comment on its relative build quality, but I have heard that it's very similar in design to the EKO. I'd like to see one up close. Tarm is comparable as well, though I don't think they make a boiler as big as the 80, which I think is 285K btu/hour. That's a biggie.

Parenthetically, when I was shopping for my boiler, a comparable Enonoburn was about 33% more than the EKO. Because of the exchange rate (Euro vs. $), the EKO model I bought is now $1,000 more than I paid. And guess what? So is the Econoburn, even though the exchange rate isn't a factor for them.

EKO has a 5-year warranty. I don't know what the Econoburn's is, but that's probably a factor worth considering as well. The Tarm warranty is 20 years. The Tarm tanks and heat exchangers are also supplied by STSS. I'm not sure what Zenon offers in the way of storage.


----------



## leaddog (Dec 14, 2007)

I'm not an expert by any means but here are some ideas. I have a eko80 with 1300gal storage. I went with the eko80 because I wanted to be able to use longer wood. (40in). After having the eko running now for 3+ months here are some of my opinions. I don't think that the 80 Puts out more btus that the 60 per hour but because of the larger wood chamber it will put out more per loading. I base that on the idea that both have the same size and number of nozzels hx tubes etc.
If you are going to be useing large storage That could be a factor.
On storage , if you are going to have to build your boiler room you might consider building your storage tank in the ground. By digging a hole and useing the blocks for walls you can insulate under and around the outside with foam, line it with epdm and have a tank that is structurally sound. You can make a large volume tank that way and the cost per gal would be less for a larger tank. Also you can make it deeper, like 8 or 10ft, an not worry about the water pushing the walls in. A deep tank would give more stratifcation which is a plus. You could very easilly have 3000gal at a low cost.
I like my eko but another idea is the Garn. It has the storage build in and would be very adapable to any boiler room you might build. I know some here have a garn and there is a dealer here in Michigan (heaterman) I think that might chime in and be able to tell you more. They cost more but if you are going to build storage and a boiler room they are a proven boiler.
leaddog


----------



## Eric Johnson (Dec 14, 2007)

It's rated for 80kw vs 60 for the '60, leaddog. But I defer to your more experienced opinion.


----------



## Father John (Dec 14, 2007)

Thanks for the notes about the Garn. I did attempt to look into Garn, but after leaving a couple of messages, and having heard no response, I think they are not interested in our project. Those I talked to at New Horizons and Econoburn were exactly the opposite: very interested and very helpful. 

As far as building a subterranean tank goes, that wouldn't be too hard. We still have a Kubota mini-excavator and a small pile of rebar left over from our major construction, so I could easily build a reinforced aerated block tank, and waterproof it. Would this not complicated the hx installation, or the connections that are needed, though?

I am still not exactly sure I know how many lines will have to go in and out of this tank.


----------



## Donl (Dec 14, 2007)

nofossil said:
			
		

> Father John said:
> 
> 
> 
> ...




I showed my wife the picture of the monastery plumbing.  She said to me that that is exactly what a fellow can do when he doesn't have to take into consideration the WAF.


----------



## leaddog (Dec 14, 2007)

I know that is the rateing , and I maybe very wrong ( won't be the first time) but with the nozzels being the same, fans same and heat tubes the same the only difference I can see is the length of wood chamber. I have one more block in the bottem and so the area of the gasification is larger. maybe the added area of the wood chamber will put off more gas and so the nozzels will burn hotter but the nozzels are two and look to be the same. I really don't think it makes a difference because with the 80 you will get a longer hot burn than the 60. That may be how they come up with the rateing is by the total btus per load per burn time. If you have enough storage to use the btu's in the 80 then you are better to get it, if  not then the 60 will work. 
From what I see in boilers in general the btu's are a subjective thing. They have to size them so the small is small and the large is large. It makes a difference what you burn, how you burn, and how efficient.
like I said just my take on it.
Leaddog


----------



## leaddog (Dec 14, 2007)

Father John said:
			
		

> From what I heard today it seems that Econoburn has just committed to STSS to sell their tanks when storage is needed in future installations. This seems odd in light of what Econoburn told me just a day ago, about storage being needed by other boiler designs, but not by them.
> 
> Econoburn did say they thought the EKO was not very heavily built, in comparison to their boiler, but I just got the shipping weight of the EKO 80 - 2380 lbs on steel pallet, incl. wooden crate - which sounds pretty heavy to me. At only 65% of the cost of the Econoburn, is the EKO too good to be true? Are there any hidden problems with the EKO?



 when any manufacture tells you that their product is better than and other with out proving their point they become suspect. To sell a product you only need to show how your product will do the job it is intended to do. 
I feel the eko is very well built and is build to do the job. I have not seen a Econoburn. I have looked at some of the other gasifiers out there and most of them have their selling points. Everyone has to look at them and look to see what will fit their situation. I narrowed my choices to the Tarm, Eko, Wood gun, garn. They all seemed to be good but the eko fit me.
Leaddog


----------



## Eric Johnson (Dec 14, 2007)

I don't see where an inground tank would make any difference in the hx installation, function or piping. I think it's a great idea.

DonL's reference to the WAF is "Wife Approval Factor" by the way. But presumably you have somebody else that you need to keep happy.


----------



## BrownianHeatingTech (Dec 14, 2007)

Father John said:
			
		

> As far as building a subterranean tank goes, that wouldn't be too hard. We still have a Kubota mini-excavator and a small pile of rebar left over from our major construction, so I could easily build a reinforced aerated block tank, and waterproof it. Would this not complicated the hx installation, or the connections that are needed, though?
> 
> I am still not exactly sure I know how many lines will have to go in and out of this tank.



The heat exchangers drop in from the top, so piping isn't an issue.

Making sure the top cover seals well, is, or you end up with a steam room.  If you're doing an in-ground, you also want to take safety into consideration, so folks don't use the cover for a walking surface, or even for storage, since you'll want it to be light enough that it can be removed every couple of years, at least, to maintain the water quality.  You also want to make sure to insulate the tank well, or you just end up heating the ground.

Regarding the boilers, the Econoburn is an extremely high quality boiler.  It's one of the best-built boilers around, and it comes with a price that matches its quality.

A 2000-3000 gallon tank would serve you well.  4000 would be even better, but it all depends on what you want to spend.  Bigger tends to be better, within reason.  At your heat loss (based on the one boiler being able to heat the place), a 4000-gallon tank would likely handle the better part of a day, at the maximum load, and longer than that when the load was less (warmer weather).  I think even 2000 gallons would make you very happy in terms of infrequent boiler tending.

Joe


----------



## heaterman (Dec 14, 2007)

Father John

I sell both Econoburn and Garn and I think for your particular application I would go with the Garn for the following reasons.

First of all, you do want a substantial storage or "buffer" tank. The high mass of your infloor heating system will be handled much more ably by the appropriate mass to counteract it. What many in this business don't grasp is that the load generated in bringing a slab of cement up to temperature is greater than the amount of heat needed to maintain it and the room. It's like a huge flywheel in that it takes a lot of energy to get it spinning but a much smaller input to sustain it once "running". The use of a "buffer" tank will provide a shock absorber for the initial load while allowing the boiler to "recharge" the tank at it's leisure.  When the slabs are up to temperature and you have the boiler sitting at 170-180*, you now have gobs of btu's stored up to use as needed when the slabs cycle or the weather changes. Overheating a Garn boiler takes a severe lack of attention because you have 1,500 or 2,000 gallons, depending on the model, to play with. The Garn has this storage capability integral to it's design in that the tank is part of the boiler itself.

I really like the fact that when you open the fire door on the Garn, you will not be given a convincing simulation of what standing at the gates of Hades must be like. Smoke bellowing and flames licking at your face just don't happen due to the very intelligent design of the airflow on the Garn. The combustion air is drawn through the firebox rather than pushed into it like any other wood burner I have seen.  This is a powered draft instead of a natural draft created by a chimney as in the case of an Econoburn or Eko. As a result of this there is a negative pressure at the feed door rather than a positive pressure. It's nice to keep the fire inside where it belongs.

Control for the Garn consists of a simple wind up timer that contols the run time of the combustion blower. Dial in an hour and a half if your water temp is close to target and you only need a half a load of wood to get back to 180* (or whatever * you pick) or fill it all the way and wind it up for 3-4 hours. Walk away and forget it.  This would be a decided advantage where you may have multiple operators.

The fact that the Garn is an open or non-pressurized system can be viewed as positive and negative. Negative in that it means you will need to incorporate some type of heat exchanger to isolate it from the sealed and pressurized side of your system.  Positive in that it can never "blow up". 

In defense of the company as far as poor communication is concerned, they have been absolutely swamped with work and a planned addition to manufacturing capability this fall hasn't materialized due to floods experienced in Minnesota which caused a shortage of electrical service equipment needed to bring their expansion on line.  Martin Lunde, the owner of the company and designer of the Garn boiler has been out West engineering the heating system being used in a very large corporate retreat for (get this) an oil company. They are very short of help so if you would like to contact someone regarding one of these units, please feel free to call me at 231-920-4808 at any sane hour of the day. I'd be happy to lend what meager expertise I have to your project. 

All of this is not to say the Econoburn or EKO would be a poor choice. It's just that by the time your build or buy storage which your system really needs, you have virtually the same cost and probably more effort involved as if you purchased storage and boiler in one unit.

I hope I have shed a little light on your path.

May you have a Joyous Christmas season and a Happy New Year.


----------



## Eric Johnson (Dec 14, 2007)

I agree that the onboard hot water storage offered by the Garn is probably a more economical solution in many cases than discrete heat storage, especially when you can replace an expensive copper coil or other copper contrivance with a flat plate heat exchanger. But in most residential applications (though perhaps not in a large facility like a monastery), I would think that being able to bypass the storage and go directly into the zones has some real potential advantages. Momentum and flywheel effects are great, but only when you're ahead of the game. Get behind, and you're in for a long, long wait. And as clean as EKOs, Econoburns and Tarms burn, I suspect the Garn is even cleaner. It's a really nice rig, I agree.

As for pressurized boilers blowing up, it's not something I've ever lost a lot of sleep over. If it's a concern, why not put in more than one pressure relief valve and/or some other scheme like an aquastat-activated zone valve that virtually guarantees safe operation? I know boilers occasionally blow (as do water heaters), but I think that's a red herring.


----------



## Father John (Dec 14, 2007)

Many thanks to all who commented about our needs and the boilers available. Thanks also to Nofossil for the kind words and the excellent page with the unusually lucid description of how these systems work.

I remain quite interested in Garn, and hope that we will be able to speak to the company itself before purchasing. I don't have any great fear of a boiler exploding, and putting the unit out in an aerated concrete building will guaranty no danger to life or limb if the unthinkable should happen. The Garn may work well for us in that we have not yet waited for the concrete floors to cool down before we begin to heat in the fall, so have never had to heat entire zones from a "cold start". We do have enough fuel oil and a diesel generator to keep us going for quite a few weeks if it got really bad, so even during ice storms I don't think we would have to wait for  the boiler to heat up frigid zones.

On the other hand, who can predict the future? I see now one of the major differences between the Garn system and the wood gasifier coupled with a tank.


----------



## Eric Johnson (Dec 14, 2007)

Let us know how your project proceeds, Father John.


----------



## Eric Johnson (Dec 14, 2007)

Father John said:
			
		

> Eric, thank you very much for the explanation of the dealer's attitude about storage. I am trying to determine storage type and size right now, since we will be using some of the aerated concrete blocks left over from the monastery construction to build a boiler/wood storage room off the end of the garage. I am wondering if the aerated concrete (because of its thermal mass inertia) would be a suitable material to use for a tank, or would epdm lined plywood be better?
> 
> Also, is a flat plate hx suitable for a 1000 gals tied to an EKO 80, or are copper coils/loops required?
> 
> ...



You might want to consider filling the voids in those blocks, if they have them, with vermiculite for extra insulation.


----------



## Father John (Dec 14, 2007)

I am making one more attempt to get an idea, at least a rough idea, about the cost and sizing of a Garn, before we have to push ahead with a decision limited to the other boiler companies. I suppose I will put the question of building our own tank on the back burner until we see what Garn can do, since their boiler would render the extra tank project unnecessary.

In the meanwhile, if I may ask, what is the best way to carry the heat inside? It will be 60-80 feet between the new exterior boiler room and the current system in the kitchen basement. Since the water line from the well and the current domestic hot water heater are both in this basement, I suppose I will also need an extra pair of insulted lines to bring dhw as well as the water for the radiant loops.


----------



## Eric Johnson (Dec 14, 2007)

It would be easier and cheaper for you to put a heat exchanger for DHW on the supply line after you get it to the distribution point, so there's no need to run a separate line out to the boiler. You can use an external hx on your existing water heater or an indirect water heater & put it wherever you want., probably right next to your existing water heater.


----------



## Father John (Dec 14, 2007)

That sounds like a better idea to me, not least because it is easier. I guess a homemade shell-and-tube of copper would do it.

On the boiler question, it looks like somebody who knows the fellow at Garn will be contacting them for us, so hopefully we will finally be able to see what can be done.

It occurred to me to wonder whether the wiring on the EKO, being from Poland, caused any difficulties when you have to hook it up over here? Are there any other things aside from electrical matters which cause problems in the translation?


----------



## Nofossil (Dec 14, 2007)

Father John said:
			
		

> That sounds like a better idea to me, not least because it is easier. I guess a homemade shell-and-tube of copper would do it.
> 
> On the boiler question, it looks like somebody who knows the fellow at Garn will be contacting them for us, so hopefully we will finally be able to see what can be done.
> 
> It occurred to me to wonder whether the wiring on the EKO, being from Poland, caused any difficulties when you have to hook it up over here? Are there any other things aside from electrical matters which cause problems in the translation?



My EKO came with a standard 110 volt US-style plug, just like a food processor. Kind of funny on an appliance that's so large. The controller is dual-voltage, and mine has an added internal transformer to step up the voltage to run the 220V blower. No voltage problems at all.

My only issue was that the pipe threads were not exactly correct - I had to rent a threading die and dress them up in order to get standard Chinese-made US NPT pipe fittings to work. I think they've addressed that issue, as I haven't heard of anyone else having that problem.

Once in a while I wonder how easy it will be to get a replacement blower if mine fails. The more of them that there are, the easier it's likely to be.

Speaking of 'translation', the version of the manual that I got is far more entertaining than informative.


----------



## leaddog (Dec 15, 2007)

The eko's now come wired for 110. That includes the blowers, controler, and pump. My 80 was wired for 110 but they mistakenly lift the stepup transformer on and it blew up the controler. Covered under warrenty. The pipe threads were standard so I had no trouble hooking it up. Parts seem to be available and seem to be very reasonable through CozyHeat.
leaddog


----------



## Eric Johnson (Dec 15, 2007)

The older 60s and 80s had flange connections to the supply and return ports, but they've been replaced with standard 2" threads. I didn't have any problems with that. My wife wondered why the supply pipe extends so high up above the top of the boiler (I don't have much headroom in my boiler room). It's so you have enough clearance to get the top covers off.

I had no trouble with the electrics. Just hooked it up and ran. Mine did come with a small electric gizmo that looks kind of like a fuse or something. I've never figured out what that's for. I guess I could post a pic if nobody knows.

The nice thing about having two blowers, leaddog, is that if one goes down, you can block off its nozzle and keep going with the other one. They're nice quiet blowers.


----------



## Father John (Dec 16, 2007)

This line of questioning of mine on the merits of EKO and Econoburn may be turning into a thread about Garn, as I am increasingly interested in its possibilities. It may be that it is ideally suited to our large masonry building, with its own flywheel effect.

While I eagerly await hearing from the Garn company itself, perhaps someone can tell me what is the simple way to measure actual hourly Btu use in a system, since that is an answer I should be able to provide to these different manufacturers. Our radiant system now is being run only by oil fired boiler, to my great regret.

Thanks again for all the invaluable help.


----------



## Nofossil (Dec 16, 2007)

To a first approximation, look at your oil deliveries from last year. Oil provides about 115,000 BTU per gallon in a typical boiler. If you know how many gallons per month you used, you can do the math. Since you only use one boiler, it will be less than 140,000 BTU/hr.


----------



## Father John (Dec 16, 2007)

Well, I might have guessed the simple way wouldn't work for us. You will have to tell me now what the complicated way is.

We have a 2000 gal tank buried, and we buy oil once a year, usually in late summer when it seems to be a little cheaper, so I don't have a clue what the monthly usage is. I also didn't record exactly how many weeks we heated last year, so I don't even know what our seasonal average was.


----------



## Eric Johnson (Dec 16, 2007)

I can't speak for nofossil, but I suspect he will prescribe what's known as a heat loss calculation on the spaces you're trying to heat. You can download a free one here:

http://www.heatinghelp.com

Or hire a heating contractor to do one for you. Oftentimes that's included for free if you're asking them to spec and quote a system for you. You may have had one done as part of your oil boiler installation, and it would probably still be valid if your physical plant hasn't changed too much since then.

A couple more items I thought about the other day pertaining to our discussion here:

1.) Boiler weight doesn't tell you a whole lot about relative quality, though I agree that heavier is probably better. However, much of the weight in a modern gasifier is refractory cement, both at the bottom of both combustion chambers and cast into the doors and other parts that don't have water behind them. My point is that you can build a heavy boiler that scrimps on the steel. I'm not saying that's the case with either of the quality boiler you're considering, just pointing out that it's not necessarily a good basis for judging quality.

2.) And yes, you can build your own shell/tube heat exchanger for domestic hot water. I built mine for less than $100. They're called sidearm heat exchangers, and the great thing about them is that they work on gravity on the domestic water side, so that you can get by with one less pump compared to some of the alternatives, such as a conventional shell/tube or a flat plate. I have a thread around here somewhere describing how to build one and how they work. Maybe I'll update it with some actual specs if I get a chance. It's not the perfect DHW setup, but it's pretty good, and it's a satisfying DIY project to boot.

https://www.hearth.com/econtent/index.php/forums/viewthread/8168/

Finally, we have a couple of dedicated Garn owners who participate here, so no matter which way you go, I think the Boiler Room has got you covered. As you may have noticed, the learning curve on these things is diminished significantly when you can compare notes with other people who have them.


----------



## Father John (Dec 16, 2007)

Eric,
  Thanks for the info on the sidearm hx. That looks like an easy project. I like such a simple solution to that particular problem.

On the question of the Btu usage of our building, I do have already a heat loss calculation, done professionally just a few years ago, before we began construction. My understanding is that it tells us how much heat the building may require to heat to a certain thermostat setting when it is a certain temp outside (our average yearly low). What I am wondering now is how to find out how much heat the building is actually using, on average, since the calculations done by the software are usually a worst case requirement during the coldest time.

Do I have to sit next to the boiler and count and time the firings during a certain number of hours?


----------



## Eric Johnson (Dec 16, 2007)

My understanding, soley based on lurking around professional heating websites is that your "design day" is either the coldest average day for your area, or close to it. Then in most cases you size the boiler to heat the space to a reasonable temp. on that day.

With oil or gas it's not a big deal having a boiler that's bigger than you need for the vast majority of your heating days, because gas or oil simply turns on or off as needed. Wood, on the other hand, doesn't lend itself to abrupt starts and stops. Once you load the firebox, you pretty much need to let it run its course. That's where hot water storage comes in handy. It gives you the flexibility to fire hard even on relatively warm days.

With a storage tank, you can either undersize or oversize your boiler to some extent and get away with it. And there are legitimate reasons to do both.

How's that for confusing the discussion?


----------



## Father John (Dec 16, 2007)

Now that I am beginning to grasp the use of water storage, it is for that exact reason that I am trying to see what the actual heat loss is, as opposed to the calculated heat loss at zero degrees outside. From what I have read, the pros do not expect us to spend more than 2% of the season at the outdoor design temperature. I think it has actually been 4 or 5 years since we got down to zero here, and that was only one morning. Wind chill (we are having a lot of it right now!) is another matter.

So, basically I am trying to determine how much water storage our building should have for average times. Our initial design temperatures were zero outside and 70 inside, in which case it was predicted the building would require 276,602 net Btu/h (228,255 Btu/h as radiant panel output and 48,347 Btu/h being the expected heat wasted from the back of the panel, i.e. towards the ground). 

Cost will probably prohibit sizing the water storage for this worse case scenario, so I am trying to find a reasonable average to design for, which will let me guess how long between fires during "average" weather. Since I don't have any regular fuel bills to calculate from, what would be the next method?


----------



## EForest (Dec 16, 2007)

checkout this thread by TCaldwell garn boiler feedback pleaseHe used a simple analog clock wired into the oil burner relay.
If the boiler fires the clock starts then stops when the burner stops.
after 24 hrs you can do the math x the burner gal/min rating, etc...
best of luck!


----------



## Grover59 (Dec 16, 2007)

I have had a clock hooked to my burner for the last 20 years, now I also have one hooked up to my aquastat for the blower on my wood boiler. This clock is a new electricl alarm clock that has a light and is located in my bedroom this way I know when the blower is running and how long without having to go down stairs. Next I will get the remote thermometers this is a hobby, but it is also saving me lots of money at the same time. 

Steve


----------



## Nofossil (Dec 16, 2007)

Next thing I'd do is take your annual consumption and divide it by the degree days for your area for the heating season - that will give you gallons per degree day. Then, look at the peak annual weekly degree days and multiply it out to get gallons per week. Divide by seven and multiply by 115,000 and you'll a reasonable seasonal worst case based on actual consumption rather than the more extreme daily worst case used to size oil boilers. 

http://www.wundergound.com has an almanac. There's a link on the left side of the page - a place to choose a data and a 'Go' button. The 'daily' tab has the best data - look at data for each Sunday to get a good profile. One of the things it shows is actual and average degree days for the whole heating season (from July 1, I think).

I'll help crunch the numbers if you'd like.


----------



## Father John (Dec 16, 2007)

> Next thing I’d do is take your annual consumption and divide it by the degree days for your area for the heating season - that will give you gallons per degree day. Then, look at the peak annual weekly degree days and multiply it out to get gallons per week. Divide by seven and multiply by 115,000 and you’ll a reasonable seasonal worst case based on actual consumption rather than the more extreme daily worst case used to size oil boilers.



I will need to get the brain warmed up to keep up with you nofossil; it must be the biting wind we're having here.

I found that over the last 8 years we averaged 4980 heating degree days. I am still looking for the file with the oil bills in it, so I will take 2000 gals as my number for now. Dividing the gallons by the degree days I get 0.4 gals (although I do remember the bills well enough to think this number is much too low).

Where I am stuck is with the peak annual weekly degree days. Does this mean how many degree days are in the week with the most degree days of the year? Presumably that would be in January?


----------



## mikeyny (Dec 17, 2007)

I think The Garn is the best setup for your situation . As we all know, heating systems are designed for the coldest day of the yr., but we only have a few of those each yr. If you already have an existing heating system it is not a bad idea to undersize your new wood boiler. If you do use concrete block, epdm liner and styrofoam on the outside for your storage tank, don't forget to factor in the thermal mass of the block.


----------



## Nofossil (Dec 17, 2007)

Father John said:
			
		

> > Next thing I’d do is take your annual consumption and divide it by the degree days for your area for the heating season - that will give you gallons per degree day. Then, look at the peak annual weekly degree days and multiply it out to get gallons per week. Divide by seven and multiply by 115,000 and you’ll a reasonable seasonal worst case based on actual consumption rather than the more extreme daily worst case used to size oil boilers.
> 
> 
> 
> ...



Yes - I don't remember when the coldest week is, but January seems about right. If you go to the almanac that I linked to, you can look at two dates in January a week apart and look at the average 'season to date' degree days. For us up here, a typical week in January might be 330 degree days. That would be about 47 degree days per day. If we had your oil consumption of .4 gallons per degree day, that would be about 19 gallons. At 115,000 BTU per gallon, that would be about 2,000,000 BTU/day. Dividing by 24 hours, about 90,000 BTU per hour average during the coldest week.


----------



## Gooserider (Dec 17, 2007)

Father John said:
			
		

> Now that I am beginning to grasp the use of water storage, it is for that exact reason that I am trying to see what the actual heat loss is, as opposed to the calculated heat loss at zero degrees outside. From what I have read, the pros do not expect us to spend more than 2% of the season at the outdoor design temperature. I think it has actually been 4 or 5 years since we got down to zero here, and that was only one morning. Wind chill (we are having a lot of it right now!) is another matter.
> 
> So, basically I am trying to determine how much water storage our building should have for average times. Our initial design temperatures were zero outside and 70 inside, in which case it was predicted the building would require 276,602 net Btu/h (228,255 Btu/h as radiant panel output and 48,347 Btu/h being the expected heat wasted from the back of the panel, i.e. towards the ground).
> 
> Cost will probably prohibit sizing the water storage for this worse case scenario, so I am trying to find a reasonable average to design for, which will let me guess how long between fires during "average" weather. Since I don't have any regular fuel bills to calculate from, what would be the next method?



As an amatuer in these sorts of things, it seems to me like it almost doesn't matter what your average consumption is - build for as close to your worst case as economically feasible, and experience will rapidly teach you how often you will need to fire depending on the weather.  As mentioned earlier, the tank is essentially a battery.  The size of the tank will determine how much "charge" you can put in it - the heating demand is equivalent to the current draw, which you can presume to be somewhere between your worst case scenario and zero - the amount you are drawing from the tank will say how long you get to run before needing to fire up the boiler to "recharge" the tank.  Presumably you could put some instrumentation on the tank that would tell you when it needed firing, though I'd expect experience would quickly make that redundant.

Gooserider


----------



## Nofossil (Dec 17, 2007)

I'll agree with Goose on this one. You don't want to choose a boiler that's way oversized, but something close to your worst case would be fine. In your situation, you could fire up oil to help out on your infrequent zero-degree days.

For the tank, bigger is almost always better. My average heat load is around 20,000 BTU/hr and I have an 880 gallon tank. I can skip days at both ends of the season, but during winter I build a fire that burns an average of about 7 hours per day, and the tank carries me between fires so that the house temperature stays constant. I don't have radiant, so I can't use as much of the heat in the tank as you''l be able to.


----------



## heaterman (Dec 17, 2007)

Question for Father John:

Do you have any make up air or ventilation equipment for air exchange in the building(s)?  If so this would have to be incorporated into the actual heat loss for the structure. I see a duct in one of the mechanical room pictures but I'm assuming that it's there to provide combustion air for the boilers.


----------



## Father John (Dec 17, 2007)

That is a good question heaterman, and a fact which I believe was probably left out of our original heat loss study. We do have a Greenheck 200 cfm fan in the end of a main vent line, which exhausts all the bathrooms. The duct in the basement is for make-up air. It has two motorized dampers which we wired to the firing controls on the boilers.

Nofossil, I worked it out that our average heat loss was probably about 90,000 btus/hr last year. This seems to correspond with experience, since a 144,000 gross Btu boiler should produce about 120,000 net btus/hr on the smaller nozzle (which I think is what's in there).

The smallest Garn (if that isn't a paradox) is supposed to be able to store 920,000 btus, so I guess that would mean for us an average day would require two burns, more or less.


----------



## Nofossil (Dec 17, 2007)

Father John said:
			
		

> That is a good question heaterman, and a fact which I believe was probably left out of our original heat loss study. We do have a Greenheck 200 cfm fan in the end of a main vent line, which exhausts all the bathrooms. The duct in the basement is for make-up air. It has two motorized dampers which we wired to the firing controls on the boilers.
> 
> Nofossil, I worked it out that our average heat loss was probably about 90,000 btus/hr last year. This seems to correspond with experience, since a 144,000 gross Btu boiler should produce about 120,000 net btus/hr on the smaller nozzle (which I think is what's in there).
> 
> The smallest Garn (if that isn't a paradox) is supposed to be able to store 920,000 btus, so I guess that would mean for us an average day would require two burns, more or less.



90,000 BTU/hr seems like a very reasonable number in light of everything else you've mentioned. I don't know what the BTU/hr rating is for the Garn when it's firing, but if it stores 920,000 btus then you can go ten hours between fires - probably a bit more, since the building itself has some mass and it will presumably be warm at the end of your fire. Of course, the 'between fires' interval will be shorter in cold weather and longer in warmer weather. My average pattern is seven hour fire, seventeen hours living off the tank. When it's really cold, it's more like 12 and 12. When ist's warmer. it might be 8 and 40. The tank gives you some flexibility.

When Garn calculates their 920,00 BTU of heat storage, do you know what temperature they consider to be 'depleted'? For baseboard heat anything below 120 is pretty useless, but for radiant you can use stored hot water down to around 90 degree - a big difference.


----------



## heaterman (Dec 17, 2007)

IIRC, Garn's storage capacity is based on an 80* temperature drop so let's say for the sake of discussion your talking about 200-120* which is still plenty usable for an in slab radiant floor such as Father John has. If 90,000 is an average heat loss, I'd say it's safe to assume a cycle time of 10 hours on average. More in mild weather and less at sustained design conditions.  The lowest design temperature for Virginia I could find on my heatloss program was 10*F. I'd guess 90-110K is going to be close to real world conditions for the monastery.


----------



## Nofossil (Dec 17, 2007)

heaterman said:
			
		

> IIRC, Garn's storage capacity is based on an 80* temperature drop so let's say for the sake of discussion your talking about 200-120* which is still plenty usable for an in slab radiant floor such as Father John has.



I'm not familiar with the Garn design, but 200 degrees seems really high for a storage tank. Does the Garn idle when the tank is up to temp? Otherwise, it would seem that you're at some risk of boiling if you put a bit too much wood in it.

My tank is external, and my boiler outlet is around 185 max. I've never gotten the average tank temp above 165 or so. If the Garn can reach an average tank temp of 200, that's pretty impressive.


----------



## heaterman (Dec 17, 2007)

200* is not a problem because with 1,500 gallons of integral storage, it still requires a bunch of BTU's to push the water temp up to 210*. There is no "idle" with a Garn. It's either at full burn or off. Idle in a Garn is when you are simply using the heat stored in your water which can happen even with a stone cold firebox. 

You are correct and prudent in keeping your EKO and remote storage at the temps you indicated. A safety factor of 30* is a good thing in my humble opinion.

(1,500 x 8.33 x 10*) = 124950 btu


----------



## Father John (Dec 18, 2007)

It looks like we are going with the GARN. They gave us a price we couldn't refuse, as I found it would be impossible to put together a decent gasifying boiler and similar sized tank with all the odds and ends and come out ahead. This is in spite of very generous discounts from Econoburn, Eko and STSS.

The model is the 1500, which has about 1420 gallons water storage and is rated at 350,000 Btu/hr. The big question now will be whether we should cut into our current boiler loop and redo so that the GARN is feeding the radiant zones directly, or use a heat exchanger. My understanding is that piping directly will allow us to draw more usable heat out of the storage tank, maybe even down to 100*. It will be a pity to have to redo the piping, but if it makes sense in the long run, it has to be done.

By the way, I found the fuel records, and it turns out we averaged 50,163 Btu/hr in Nov-Jan last winter, which was unusually mild, with the average in Feb-Apr going up to nearly 90,000 after we got the library zone hooked up and the weather got much colder.


----------



## Gooserider (Dec 18, 2007)

Sounds like a garn good decision.....  :lol:   (Couldn't resist....)

As to the plumbing, I'm not an expert, but I would see if Garn had any specific advice as my first approach.  If they didn't, I would say that if the Garn is providing pressurized storage, then go with direct piping, if it is non-pressurized, go with the heat exchanger...  I shouldn't think it would involve all that much cutting into your existing plumbing either - I assume you already must have some sort of inlet and outlet manifold to tie your existing boilers together and into the circulator loops, I'd just add another connection into that piping.  

Gooserider


----------



## Happy (Dec 19, 2007)

I am also trying to order Garn boiler.I left several messages at their phone no. for last 10 days.I got 1 response back 3 days ago saying some salesman will contact me from my area.They did not give me contact information for this salesman.Now I am waiting for his call for last 3 days.I understand it takes 6 weeks for delivery and I have to decide fast if I want to wait longer for Garn or go with Orlan EKO.Garn has great product but if they are not ready to sell then it is just imaginery product for me.I talked to Tom from CT in detail about Garn who is using it and I am impressed.I am posting here and hoping to get some other contact information to one of the local salesman in New England.Do anyone know cost of Garn 2000 ? I have read on some other thread that it is close to $12,000. What are other cost I should expect.I currently have my 350k oil boiler in basement of main building.Oil boiler directly feed baseboard heat for 7000 sf building.It also heat two 80 gallons DHW tanks via one flat plate HX.The garn will be in my car garage.Two boilers will have distance of about 80 feet.But the distance between two Building is only 30 feet.So my understanding is I will need underground piping for only 30 feet.Tcoldwell, is it possible for you to post rough diagram for your system or pictures of your system? In future I will also have about 3000 gallons of hot water storage in my existing 21'x10'x5' concrete tank.I will have to insulate it and build a partition in the middle to seperate cold and hot water storage.

P.S. - I just got call from Garn when I was writing this post.They gave me local contact no. for chris from floor heat systems.I am going to call him.


----------

