Outdoor wood boilers review

[pdboilermaker]

My buddies and I have outside wood boilers, we have had them for a couple of years now. Of course we meet at the fence row to cuss, fuss, and discuss which one is better. The WoodMaster, the Central Boiler, or the Heatmor. I dont know about you but my buddies and I had to buy different brands just so we could argue.

The one thing that we can all agree on is we wish that woodboilers were listed on epinions or a similar sight so that newbys as well as us could find out the pros/cons etc of each woodboiler such as expected issues, wood consumption etc. made by each of the now dozens of new manufactures. Does anyone know of such a sight? Shall we just start one here?

While it is fun for the 3 of us, that is a low sample of 1 piece of data per manufacturer. To make a good descision, you would need much more data to identify any trends.

 

[Eric Johnson]

I'd like to get some honest answers on wood consumption for various brands/types of boilers. I think some people lie about how much wood they burn, just like some people lie about their gas mileage. I know there are important variables, but maybe discussing those would be useful as well.

 

[JustWood]

I don't own an OWB myself ( so my opinion is unbiased). WOODCO provides 1-2000 customers a year their yearly wood supply, so I get to talk to alot of stove and OWB owners . Over the years I have asked many OWB owners the pros and cons. Central Boiler seems to have the best reviews and least complaints. I recently advised my father to buy a Central Boiler. Just fired it up in the last week or so and he loves it. I'm impressed with how well it works without a forced draft.like many models have.

 

[pdboilermaker]

OK then we will begin here with the comparisons I suppose:

1. The home and conditions:

I live in North Central Indiana, in the country close to Kokomo

I am heating a 100 year old farm house that is 3300 square feet of a well insulated (R38 in celings / R19 in the walls) two story home using a forced air furnace for the upstairs and a forced air furnace for the downstairs

I have little to no windbreak (come on planted trees, grow), and the wind really whips around here, especially in fall, spring, and winter

My typical propane bills (prior to the boiler installed in March 2005) were about $2000/year with two 90+ furnaces and a tankless hot water heater

I have always used digital kickback thermostats with the following settings: 445am 70, 7am 50, 430pm 70, 930pm 60

2. The boiler:

It is a Woodmaster 4400 made with mild steel, 125 gallons of water, fan induced draft

Woodmaster themselves said that the stainless steel is not a good value for the money and they sell stainless also. My friend with a Central Boiler was told the same thing by their engineers as well.

It sets about 30 feet from the house

1" pex line buried about 34" in the ground

Smoke looks like when you first start a campfire for about 10 minutes then it goes away, while idle, smoke looks about like what comes off of a big fat cigar

I use it to run my upstairs furnace, my down stairs furnace, and heat my water

Boiler does NOT run year round, it is not worth the effort (to me) to run it in the summer just to heat our domestic water

Boiler typically runs from mid October to mid May so like 7-8 months total per year

3. The wood:

I burn any kind of wood from pine (in the cooler months) to hardwoods (in the midst of winter) and telephone poles ($1.00 each from our local utility) that are used for those sub-zero days and nights with the really low wind chills

My neighbor is a tree trimmer so I have an unlimited supply of fire wood

Many of my co-workers donate their fallen down trees if I will cut up and remove

In the town I work, there is a saw mill that makes pallets (from hard wood only) you can buy their scrap, typically 8" x 8" x 24" to 36" for $20.00. That is two dumps onto your trailor, truck etc. from their 5 cubic yard payloader. When its all said and done, thats about a cord of hardwood for $20.00. This is good to use if you are in a pinch because of snow or whatever.

4. Filling the boiler:

This element is so dependat on the weather so it is nearly impossible to judge. If the wind is blowing from the NW at 15-MPH but the outside temp is 32, I will burn much more wood then if the outside temp is 0 with no wind. Wind is my nemisis.

I most generally fill the boiler 2 times per day. At 6am then again at 5pm to get this type of times between fill ups, you must adjust what TYPE of wood that you use as seen above with the pine, hardwood, telephone poles example above.

I do go out often to stoke the fire. Just because I like an excuse to go outside. While I am out there, maybe I throw in a log or two each time.

5. Total amout of wood used per heating season:

I have only had my boiler for two complete seasons (now entering the third) and I estimate that I burn between 9-12 cords per year again depending on the wind.

It is hard to really judge though since I am always picking up a little wood here or there.

Right now, I have 10 cords cut and split since spring, and the boiler is going. But, on nicer days (even in January) the boys and I will go cut a truck load on the weekends just for somethibng to do.

6. The problems:

The little glass jelly jar light cover on the front of the boiler does not stay on very well


Hope that this gets everyone started so that we can do some comparisons. If we all follow this same format, it should be easy to decipher for people.

 

[Nofossil]

I don't have an OWB, but I do have an indoor boiler. I have really good data (no gas mileage stuff) on wood consumption, and I have a good baseline vs. previous experience with oil.

Summary - Oil was used for heating 3500 sq ft well-insulated house in Vermont. Oil also was used to heat domestic hot water and a large hot tub. Oil consumption was about 740 gallons per year. Of that 740 gallons, about 620 was heat / hot water / hot tub during the winter months.

First winter, we burned 3.2 cords of wood and about 12 gallons of oil for the winter months. That winter was warmer than average (2005-2006).

Next winter, we burned about 4.25 cords (+/- about .1 cords) and about 4 gallons of oil for the winter months.

My boiler is an Orlan / EKO 25, which is an 80,000 BTU/hr gasification boiler.

 

[rsnider]

hi yall love this forum lots of good info. glad to see some owb discussion in the boiler room. i currently dont have a heating source yet for this heating season but eager to buy one for next season. my brother-in-law has a empyre owb and it does about the same as just discussed. it works fine but im looking for something a little more efficient "less wood". his house is very warm and it is great but even he will say how much it uses the wood. he has radiant floor heat, forced air and heating dhw. the radiant works the best and his forced air hardly kicks on. his house is a ranch with basement 4000sft plus garages the same as me. both homes new well insulated and we installed all radiant. so far i have helped install 4 homes with radiant floor heat and they all work great no problems. obviusly my doesnt work yet no boiler ha ha. right now im using my "backup" heat pump can u say cold heat.

 

[ISeeDeadBTUs]

Ok, ok, ok . . . back up the bus. . . . did you just say that you use 8 full cord (4' X 4' X 8') to heat (no DHW production) a 1,400 residence? Cause if you did/do . . . unless your house is made of cardboard, you have a problem!!

Jimbo

 

[webbie]

Wood poles may be poisoning you, your neighbors and the environment in general.....

pentachlorophenol, creosote, copper chromated arsenate and other wood preservatives are used in them...

From another forum:
"DO NOT BURN OLD POLES!! They are listed as Hazardous Material in the disposal department. Which ever type of preservative they used to make the pole, there are serious advisories against burning them.

I used to work for "the Phone Company" and we had to read the warning papers that came with the pole shipments. They also have sheets that go in the MSDS book for "Right To Know" reading by employees, treatments for reactions to chemicals used, for Dr. information. Papers warned of possible serious dangers to people breathing in the smoke, contaminated ashes causing problems also washing off into water systems. "

Sorry to say, but OWB's deserve a bad rap if folks are doing this kind of stuff.
8-/

 

[jdurant]

i do not own an out door boiler but if I were to buy one I would by the sequioa paradise heat tranfer machine. It seems that it would burn hot with all the firebrick. It also has coal shaker grates. go to www.wdheat.com and check it out.

 

[heaterman]

I'm a licensed heating contractor in Michigan and let me say at the outset that I am 100% for renewable energy of any type be it purely heat or electrical generation or CHP. I will also say that producing copious amounts of air pollution in the form of toxic gases and particulate emission, in the name of energy "savings" is a gross mistake. Any consumption of energy should be done in the most efficient manner possible regardless of how cheap the fuel source is. Using energy in non efficient ways is what got us into this mess in the first place and it matters not what form the energy comes in. Wood, coal, oil, natural gas, or whatever, one would think we would have learned our lesson, but no, consumers still demand "the cheapest" and manufacturers happily oblige due to the regulatory vacuum currently in place. As usual our government is about 5 years behind the times, closing the barn door after the horse is already gone.

There is a lot of misinformation, poor information, lack of information and outright lies regarding OWB equipment. Most of which is "distributed" by salesmen who will say anything to make a sale and companies who, if they have ever tested for efficiency, somehow neglected to release the results. I recently heard a claim made by a company, which will remain nameless, that their unit was 90% efficient and you could tell that by the flame coming out of the exhaust. The truly sad thing is that the customer believed it.

Early this spring Warnock Hersey labs in Wisconsin tested 7 units from major OWB manufacturers and the results were stunning. Under tightly controlled lab conditions, burning 20% moisture content wood, in spotlessly clean equipment, these 7 units ran from a low of 28% to a high of 41% efficiency. This does not include heat loss from the unit sitting outside or the piping to the structure. As I understand it, agencies from several states were involved in this in order to gain insight as to what type of regulations should be applied to these. To my knowledge these test results have not been released as yet so I cannot divulge any information regarding brands. I only know of it because of some correspondence with a person in the Michigan DEQ Air Quality division. Testing has also shown that one of these units emits the same amount of particulate matter as about 1,000 fuel oil fired furnaces.


Few OWB's are actually boilers because a boiler has to be a closed system. Most are open to the atmosphere to preclude the possibility of explosion. Being open vessels they cannot be sealed from the ravages of oxygen corrosion, hence the importance of proper chemical treatment of the heating fluid. Many OWB's fail because of this fact. Many of the OWB companies were started by sheetmetal fabricating shops with virtually no knowledge of proper and clean combustion. They are as technically advanced as a pot of water over top of a camp fire.

I would not consider for myself or recommend to a customer ANY of the typical OWB equipment on the market currently. Sealed system, gasification type boilers routinely hit in excess of 80% with some like EKO, Tarm and Econoburn hitting 85-87%. Do they cost more? Only in terms of intial outlay. One doesn't have to turn over too many rocks to find that the average OWB has a relatively short life expectancy as far as heating equipment goes. Many times the initial investment including installation and cost of fuel is hardly recovered before failure occurs.

 

[Eric Johnson]

Excellent, informative post, heaterman. Welcome to the Boiler Room.

 

[Nofossil]

Early this spring Warnock Hersey labs in Wisconsin tested 7 units from major OWB manufacturers and the results were stunning. Under tightly controlled lab conditions, burning 20% moisture content wood, in spotlessly clean equipment, these 7 units ran from a low of 28% to a high of 41% efficiency. Sealed system, gasification type boilers routinely hit in excess of 80% with some like EKO, Tarm and Econoburn hitting 85-87%.

Hello, my name is nofossil, and I'm a data addict.

This post is my kind of crack. I bought the EKO for the clean burning. I didn't realize that the fuel savings were so dramatic. I've averaged about 4 cords per season for heat, hot water, and hot tub. Based on these numbers, I'd be using eight to fifteen cords per year with an OWB. This actually tallies with numbers that I've read here and elsewhere.

By my calculations, I'm getting about 18 million BTU/cord delivered into the house, hot tub, and hot water. My firewood is a mixture, about 2/3 assorted decent hardwood and 1/3 red cedar, punky hardwood, poplar, and other junk.

Amazingly, that works out to 80% - 85% overall efficiency depending on the assumptions that you make about the wood.

 

[ISeeDeadBTUs]

At 6', I don't need a soapbox to stand on.

Anyone that retreats to oil as being better for the environment based on the smoke they see from OWB (Throwing them all in one box) either is shortsighted (at best) or is protecting their position. Wanna compare 'pollution'? then

look at the whole picture

my wood fired hydronic requires

gas in my truck to go get the wood
gas/oil in my chain saw
recycling the steel in old saw chains
combustion products released into the air

How bout we look at ALL the pollution that has to happen to get th oil out of the ground, refined, delivered, then finally combusted in my boiler?


comparing the stack of an OWB to the the stack from an oil furnace is pure BS, sorry :-/

Having said that, anyone that believes what a salesman says (OWB, oil, gas, WHATEVER) at face value is scary.

Ya know what's sad? We still get advertising bombarded at us hourly about how we deserve 'nice things', nice cars', big 'nice houses'. A friend of mine recently install 3 oil boilers in a doctor's house built for two people. They are staged so as to provide the appropriate amount of heat and DHW for these two people. IMHO that's just sad and stupid. Now more and more people think the government should 'do something' about high gas prices.

Yada, yada, yada.

 

[heaterman]

Hmmmmm; where to start..........

1. To all who think that I was advocating traditional fuels such as oil, please re-read my opening statement.

2. The comparison of stack emissions between an OWB and 1,000 oil fired furnaces is to point out just how filthy a typical OWB really is. NOT how clean an oil burner is. Lord knows I've brushed and cleaned enough oil fired furnaces and boilers to flaty state that they can burn very dirty when things are not tuned correctly. This is not anecdotal look at the smoke evidence, those numbers were generated in a test by the New York DEQ. Goggle "Smoke gets in your eyes" and you should find the test results. Very interesting.

3. I agree 100% that total life cycle costs should be evaluated on any and all products that we purchase. The cheapest is seldom the best when looking at something from that perspective.

4. We installed a heating system in a 8,200 sq ft house up on Michigan's "Gold Coast" a couple years ago. The job required 5 boilers that totaled over 1MMbtu's. We heated almost 6,200 sq ft of outside cement in the driveway and approach. It had to be heated because of the extreme slope on the drive. You'd never get up the thing if there was a 1/2" of snow on it. Talk about a waste of resources........it's a sin....nothing less. No one deserves that kind of excess, not when it effectively robs someone else of that energy.

5. All forms of energy need to be utilized in the most efficient manner possible, even wood. That's the problem I have with the typical OWB's. Running a wood boiler at 80+% is easily done so why bother with something that produces half that. The only reason is low first cost, not low life cycle cost.

6. I think that there is going to be a HUGE switch to alternate fuels in very short order. Do some research on world crude oil production since 2005. It is scary to contemplate but world production has been flat to slightly declining for the last 2 1/2 years. The vast majority of the easy to get oil has been found and from here on out it gets exponentially more costly to produce a barrel of crude. Soooooo.......why not get our wood burning ducks in a row and use the best possible equipment instead of units that give wood burning a bad name.

I get the feeling I'm preaching to the choir here but I think a new paradigm is out in front of us and we better get it right this time.

 

[ISeeDeadBTUs]

Can't speak for 'All", but I got the distinct impression you prefer oil to 'traditional OWB'. I'm from NY, castigate me for the roneous - assuming it was, in fact - impression, not the rest of the fine gents here :coolsmirk:

Two things I would ask for your input on.

1)How do you define Emmisions? For example, if it's what you see coming out of the stack, then I think you've missed entirly the point of the emissions created while refining oil. As far as a 'traditional OWB' what do you actually SEE coming out the stack? I will leave the talk of the chemicals coming out to those here that understand chemistry way better than I. But if it's "particulate matter" aka unburned wood and ash . . . if the particulate matter settles out of the air and lands on the owners ground, what harm has it done?

2)If you read the entire "Smoke Gets in Your eyes" (please tell me you realize the political source of that document) you know that it took umberage with the statement that low stack temperature indicates high efficiency. Since a few of the apparently more knowledgable gentleman here also believe that low stack temp indicates a cleaner burn, where do you stand on this statement? Is the science wrong? The politician? The end user?

Jimbo

 

[georgeinct]

In my research in looking for a woodburning stove, I have come to the conclusion that I may be better off with a wood boiler instead. I have never had either so it is a new thing for sure. I agree with the contractor from MI who said that the environment should be taken into consideration and anything purchased should be hopefully as clean burning as possible. Our political system which failed to make energy independence a national priority like JFK did with getting to the moon has all of us behind an eightball unfortunately, and being held hostage by the fossil fuel powers that be until the next techno breakthrough comes along. Let's not complain too much about high prices, there is a silver lining, hopefully they will hasten the development of the new technologies that will deliver us from the geopolitical and economic energy mess that we are in. I am looking into Geothermal also, and may make a go of it but still would like to burn wood as I get it for free.

I have narrowed down the woodstove possibilities to Vermont Castings Defiant, the largest model, which is the cleanest burning stove made per the EPA or the Mansfield or the new Equinox by Hearthstone. Does anyone have any experience with any of these stoves?

If I go with a wood boiler, I have narrowed it down to HS Tarm, Econoburn, Greenwood, or EKO...HS Tarm seems to be the established name, EKO does not have much of a warranty or track record yet, Econoburn seems pricey, Greenwood looks good but weighs 3000 lbs. Obviously, there are many factors more than these. The problem is no one does unbiased independent testing of these boilers and all claims made by manufacturers are just that, claims. It is difficilt to know who makes the best.

does anyone have any experience with any of these? Surely, gasification is the way to go, I have to heat a house which is about 5200 s.f.

I would welcome and be thankful for any information.

 

[Eric Johnson]

I've got the EKO 60 and I'm very happy with it. Other people on this board have the other boilers you mentioned, plus a few that you didn't.

Welcome to Hearth.com and the Boiler Room. Hopefully we can help you make an informed decision. Gasification is the way to go, and there are a number of very good options.

 

[georgeinct]

Eric, thanks for the message. How long have you had it? How long of a burn time will it do? How much wood are you burning per season?
How did you decide on the EKO vs. Tarm, etc.? Does anyone have a Tarm, Greenwood or Econoburn?

thanks, george

 

[Eric Johnson]

I'm just getting started with it and still have a lot of work to do on the system to get it about where I want it. It's heating the house (big one) and greenhouse (old, ineffient one) with no problem. It really kicked into gear during a recent cold snap, so I'm pretty confident that it will do the job and then some. Because my tank isn't operational yet, I haven't had the opportunity to fill it completely with wood, but I suspect that on a typical winter day, with the tank, it would need to be loaded about once a day. I like to fool with it, so when I'm around, I know I'll be poking around at whenever I feel like it. Compared to my old, conventional wood-fired boiler (Royall) it produces a lot of heat for the amount of wood burned.

I went with the EKO for a few reasons: 1.) It was about $1,000 cheaper than the Tarm 60. 2.) It takes 24+" wood, which is all I have, while the Tarm maxes out at 20 inches and, 3.) The dealer and importer were very helpful before, during and after the installation with all my questions and concerns. Since I did the work myself, that was an important consideration.

The Tarm is a fine boiler with a much better warranty and a long track record in the U.S. market. I don't think you can go wrong there, but I'm impressed with the EKO so far. I especially like the mechanical heat exchanger cleaner, which I don't think is an option on the Tarm.

 

[georgeinct]

The Tarm does definitely have a good rep. and track record, but I agree I wish they made at least one size larger, my house is 5300 s.f. How many square feet are you heating, is house insulated, how warm do you keep the house? do you have radiators, baseboard, or hot air?

There is also like I mentioned the Greenwood, and the Econoburn, among others. The EKO has a short warranty which I do not like, they claim it is made from "boiler steel" and to ASME standards, is it really well constructed compared to the Tarm? Unfortunately, can't see any of these things physically side by side or get any data beased on independent testing to compare apples to apples. I mean there is no way to know which one is more efficient, puts out more BTU, is better constructed and so on, because you are relying on mostly manufacturers claims and any user information that you can gather.

I will have to just make a decision and pick one.

 

[Eric Johnson]

I've got about 3,000 square feet of old farmhouse with a couple of additions. Overall, I'd rate the insulation as fair. I also have a 12x24-foot single pane glass greenhouse. My wife likes to keep the house between 75 and 80. Domestic hot water is also heated with the EKO. All our heat is provided by cast iron radiators. Pic attached. My boiler is in an insulated, concrete block room in my barn. I pipe hot water to a gas boiler in my basement and from there it is distributed into the house zones. A separate 3/4-inch line goes directly from the EKO into the greenhouse radiant. A 1,000 gallon tank and copper hx waits in the wings.

I can't really comment on the EKO's build quality compared to the Tarm. It pales in comparison to the Wood Gun, but for twice the price, what do you expect? Looks to be made of good boiler plate, nice looking welds and it works as advertised. Plenty of refractory cast into the doors and gasification chamber. To me it looks like a typical steel plate boiler; you don't know how long they're going to last until they fail. My understanding is that Orlan is a well-known and respected boiler manufacturer in Europe. I know that Poland has a good reputation for manufacturing, i.e., shipbuilding, etc.

The EKO claims 91 percent overall efficiency while the Tarm claims something like 85%, I believe. The rated output of the EKO 60 is 205K btu/hour, compared to something just shy of 200 K for the Tarm Solo 60. Presumably they're both 60KW units. Do the math on 60KW and you come up with 205K btu.

I shut the gas boiler and electric water heater off when I'm running the EKO, so we're pretty much 24/7/365 except for when everyone is out of town.

 

[ISeeDeadBTUs]

Does anyone have a Tarm, Greenwood or Econoburn?

thanks, george

I have a GW100 here. IMHO most of the models you -and others- have been considering are good. I think each one has it's own strengths and weaknesses.

Unless it stays 40 degrees outside for a couple of months yet (Farmers' Almanac is not THAT pessimistic :coolsmirk: ) my thought would be to not rush anything for this year. That will give you time to make a list of important features, so that you can shop around and see what fits best.



Jimbo

 

[georgeinct]

Thanks for the info Eric, I had not even heard of the Wood Gun until you mentioned it, but just went to their website and did my homework. They claim that their is no heat storage tank needed, that is a good thing, from what you said I suppose they are pricey, I will have to call them and find out. It is a long term investment and I want to do it once and do it right.

Hopefully, I can find some more real world users like yourself and make a decision.

 

[leaddog]

Thanks for the info Eric, I had not even heard of the Wood Gun until you mentioned it, but just went to their website and did my homework. They claim that their is no heat storage tank needed, that is a good thing, from what you said I suppose they are pricey, I will have to call them and find out. It is a long term investment and I want to do it once and do it right.

Hopefully, I can find some more real world users like yourself and make a decision.

I looked at the wood gun before I bought the eko and they are a very nice unit. One of the selling points for me was that they had a oil gun tube installed for alternate heat that is seperate from the wood side. That was attractive to me as I had a good gun, tank, and I burn fuel oil in my tractor. I went and saw a unit that was in operation and was impressed. I do believe that they would run more efficient with storage as any time you idle You will smoke at start and that is wasted heat. The deciding factor was between the time of reserching and buying the price went up past my set limit. They are a very nice unit. That said I'm very happy now with the eko80.
The selling point for me over the Tarm was the size of wood. I cut my own wood and I cut a lot of wolf trees. That means alot of small dia limbs and I like to cut them 3ft long to make it easier to handle and less time. The 80 will take 42in long and with the storage the over capasity isn't a problem.
If you can go see a unit in operation but I do believe that most any of the units are way better that a traditional owb. Been there done that.
leaddog

 

[brad068]

Does anyone out there have a Wood Doctor Converter wood boiler. They are suppose to be a gasifying boiler. Would like to here the operation and maintenance of it.