Help me understand a bit more before I buy a gasifier

[dirttracker]

I have been using an OWB for the last 5 years. Over the last heating season, the unit developed a slow leak and after further inspection needs to be replaced. This leaves me with the choice of either replacing it with another OWB (I’ll probably go with Central as at least they are likely to be in business in 5 years) or going with a gasifier. I have been pouring over this site over the last couple of weeks and have learned quite a bit thanks to those who have shared their knowledge and experiences. However, I need to ask a few more questions to guide my decision.

Background: My house is ~1500 sq. ft. in south central Wisconsin and I heat entirely with wood (I run my LP furnace once a year just to make sure it still works) and use LP for DHW in the summer months. The house is moderately well insulated (2x4 stud walls with R13 fiberglass and 1” additional polystyrene outside, decent double pane windows, etc). Before the OWB I would use 800 – 1000 gallons of LP per year. I currently use ~ 12 full cords per winter in the OWB, 99% of the wood is standing dead elm. I own ~36 wooded acres with a considerable amount of dead and dying elm left for use as fuel. I am currently considering and EKO 40 with some type of storage. My current plans are to use 500 gallons of pressurized storage, but this is contingent on finding an LP tank that won't be outside of my budget. The EKO and the storage will be in an insulated building ~ 30 feet from the house (the current site of my OWB). I don’t have room or a good way (no walk out basement) to put the storage in the basement. I will keep the DHW plate HX, forced air HX and underground PEX that was used with the OWB. I plan on running the water temperature between 140 and 180 F as this worked well with the forced air system that I have been using.

Questions:
1: For those that own a gasifier, how difficult was it to get the stove set up initially and how much fussing did it need throughout the winter? I don’t have any problem with some work tuning the setup, but occasionally I get sent out of town for work with short notice. I don’t want to have a situation where my wife will have trouble keeping the system going. In the past years, filling the OWB has not been a problem for her, I just don’t want to get into a system that will require a lot of continual tweaking.
2: How much maintenance is required on a gasifier? Parts that are known problems or need replacement after a few years of operation?
3: Understanding that you folks on this board have not seen my house and understanding the conditions in the “Which wood stove is right for me” disclaimer above, I still have to ask if there is anyone out there with a similar setup (house size, climate, etc) who can verify the EKO 40 is approximately the right size. I would like to be able to fire the boiler once per day in all but the coldest few weeks of the year. At a minimum I need the system to hold out for at least 8 hours overnight with temperatures of –15 F. I don’t plan on using answers as substitute for good judgment, but it’s always nice to have a little more data to work with.
4: How do you gasifier users operate your boiler with respect to loading wood, etc? It seems to me the boiler would be run to bring the storage temperature up and after the boiler shuts off additional wood could be added to fill the fire box if necessary to increase the system capability for the coldest periods. I assume there will be some loss of efficiency to have the boiler idle with a fire box full of wood, but does this type of operation cause other problems?
5: For those that have made the switch from OWB to gasifier, what was your approximate change in wood used?
6: If anyone has a source for LP tanks in the southern WI, northern IL region, please let me know.

Sorry to create such a long post, but I figure its better to provide as much information as possible. If there are any additional details please let me know. Thanks in advance for your help.

Eric

 

[ISeeDeadBTUs]

Your insulation levels sound low to me. I think you need a heat loss calculation. That will tell you how much storage you need. From there you can calculate how long it will take to heat the storage, which will tell you how many successive loads are required.

I think the advantages of an OWB are that you have storage and simple operation. But those advantages are probably more than offset by inefficiency.

There are a few members here than run EKO's very successfully, some with storage, some without.

I have no vested interest in any brand - they all have advantages and disadvantages - but have you looked at the CB 'E-Classic' ? There are a couple of them on the board now. Scary cause they are new, but as you say, the company has been around a while. That also means they still employ many of the same BS artist that have gotten good at their art. :smirk:

 

[Nofossil]

sing.

Questions:
1: For those that own a gasifier, how difficult was it to get the stove set up initially and how much fussing did it need throughout the winter? I don’t have any problem with some work tuning the setup, but occasionally I get sent out of town for work with short notice. I don’t want to have a situation where my wife will have trouble keeping the system going. In the past years, filling the OWB has not been a problem for her, I just don’t want to get into a system that will require a lot of continual tweaking.
2: How much maintenance is required on a gasifier? Parts that are known problems or need replacement after a few years of operation?
3: Understanding that you folks on this board have not seen my house and understanding the conditions in the “Which wood stove is right for me” disclaimer above, I still have to ask if there is anyone out there with a similar setup (house size, climate, etc) who can verify the EKO 40 is approximately the right size. I would like to be able to fire the boiler once per day in all but the coldest few weeks of the year. At a minimum I need the system to hold out for at least 8 hours overnight with temperatures of –15 F. I don’t plan on using answers as substitute for good judgment, but it’s always nice to have a little more data to work with.
4: How do you gasifier users operate your boiler with respect to loading wood, etc? It seems to me the boiler would be run to bring the storage temperature up and after the boiler shuts off additional wood could be added to fill the fire box if necessary to increase the system capability for the coldest periods. I assume there will be some loss of efficiency to have the boiler idle with a fire box full of wood, but does this type of operation cause other problems?
5: For those that have made the switch from OWB to gasifier, what was your approximate change in wood used?
6: If anyone has a source for LP tanks in the southern WI, northern IL region, please let me know.

Sorry to create such a long post, but I figure its better to provide as much information as possible. If there are any additional details please let me know. Thanks in advance for your help.

Eric

I think it's safe to say that you would use a LOT less wood with a gasifier. In my case, I heat entirely with wood, and I used to heat entirely with fuel oil. 4 cords of wood replaced 600 gallons of oil. Since oil has more energy per gallon than propane, that's equivalent to a bit over 900 gallons of propane. It looks like my overall heat loss is almost exactly the same as yours.

To answer your questions, setup wasn't difficult. There are a few things that you need to know: You need a bit of really dry wood to start the fire and get secondary combustion going. You need seasoned wood to get satisfactory performance. You'll need a few cycles to get the feel of how to best get the fire going quickly.

Care and feeding is not difficult. Once it's going, you just load it whenever it's burned down.

No real maintenance on mine in three years, other than self-inflicted experimentation with the secondary combustion chamber inserts.

I use an EKO 25, and I've used it with and without storage. Operating with storage, I build a fire in the late afternoon or evening (earlier on colder days). The boiler heats the house to my 'warm' setpoint of 73 degrees, superheats the DHW, and heats the hot tub just in time for an evening soak. Once everything is hot, it starts heating storage. My initial load is good for about four or five hours. As that starts to die down, I'll reload it. The amount that I put in depends on how cold it is and how hot the storage is. I'll try to put in enough so that the storage will be hot enough to carry me to the next evening. On the very coldest days, I'll do a third load as I'll need to get 12 or more hours of burn time per day. If I do that, the boiler will idle a bit since it can't dump enough heat into storage when the storage is near the upper limit.

Some idling is OK and won't hurt anything.You don't want to idle with wood that's not well seasoned, and you don't want protracted idling.

One advantage of the smaller EKO 25 is that on cold days, the boiler is running 12 hours. That means I only need enough storage to cover the other 12 hours in the day. A larger boiler would heat the storage and house in much less time, so I'd need more storage to cover me until the next evening. An EKO 40 would only need to burn about 6 hours per day, so I'd have to have enough storage to cover the other 18 hours.

 

[Jim Post]

Dirttracker-

I am located near Stoughton, WI and have been using a tarm solo plus 30 (100,000 btus/hr) since 2005. My house is similar in size to yours and I used about 6 cords of wood last (very long) season. We don't have storage in our system and run it continuously November through April so keep that in mind as I work through your questions.

1) I had the resellers (Burner Boys in Brodhead WI) set the tarm in place and run the chimney while I did all the tie in to my existing lp boiler and sidearm waterheater. It was a good project for me develop my soldering ability. Once installed the boiler is mostly maintenance free. A lot depends on using seasoned wood...keeps everything cleaner. I don't travel, but my wife checks on and stokes the boiler at least once most days in cold weather.

2)Clean the ash every couple of days and clean the heat exchanger every 3 weeks or so. Fairly bullet proof once you've mastered the burning curve. Much less maintenance and fire tending when compared to a wood stove but probably more attention required than a OWB.

3)I wood reccomend doing a heat loss calc on your home using the slant fin software.

4)We pay close attention to the forecasted temps and load accordingly. In very cold weather, we can pretty much burn full out loading 3 times a day.

5) We went straight to gassifier so I am no help there.

6) Let me know too.

Shoot me a pm if you are close enough to Stoughton that you'd want to see our set up or need help removing all the dead elms on your property.

good luck!

jp

 

[dirttracker]

Thanks for the replies! I ran the slant-fin calculator and come up with 47,000 BTU/hr with a -15 F outside temp. I may need to work on timing for the coldest days as this will only give about 3 hours off of the storage. If I can time things right, I would load just before bed and with a 5 hour burn + storage I should have more than enough to make it through the night.

Nofossil, your point is taken regarding sizing. The EKO 25 may be a better option if loading is timed properly and enough storage is available. How much does the temperature in your house vary with your firing schedule? Are you saying you get 4 -5 hours out of a full fire box load with the stove running continuously?

DeadBTUs, I thought about the EClassic, but don't want to be a guinea pig for a companies totally new (to them) technology or product. Besides, after 5 years of loading the OWB in most all types of inclement weather I figure it would be nice to do this task in a relatively warm and dry location.

olpotosi, I live a bit south of Monroe so the dead elm would come with a hefty gas cost to transport to Stoughton. I'll definitely check out Burner Boys, I see they are and EKO dealer now.