I am looking at replacing a traditional fireplace with a wood stove insert that can be used in a hydronic floor system.
I looked over your article on the fireplace you installed in your home and have spoke to and web searched for wood stoves that circulate water for heated floors and find only the “long burners” for outside or commercial “furnaces”, nothing that would be appropriate for a great room/ranch application. Can you point me toward manufacturers that have this type of product?
Thank you.
Mark J. Bechtel
Mark,
As I mentioned in answers to similar questions to this web site, most of these manufacturers have gone out of business due to not being able to meet new regulations and codes related to wood-fired boilers. There are several web sites that describe how to build your own, but installers are switching to the outdoor models for safety.
I feel our hydronic fireplace system is very safe, but I have included both a temperature and a separate pressure relief valve, and a way to keep the pump working if there is a power outage. Many of these early systems were well made but the piping systems were poorly designed and installed.
I purchased a Central model 2300 wood boiler with propane backup.
I am located in Butte, Montana and the normal wood of choice is Pine.
The wood burning part seems to work sort of adequate, although the fire frequently goes out. The main problem is the creosote that collects on everything inside the fire box. The propane gas nozzle has an electrode on the end of the gas nozzle which sticks inside the firebox. However, due to the creosote collecting on the end of the gas nozzle, it normally does not work after a week or so after I clean it.
In other words, it is pretty iffy, if the gas backup is going to fire or not. The creosote is so thick is makes a black sticky mass that covers the entire end of the gas nozzle.
Central has worked with me to correct the problem. They had me install a larger combustion fan that they felt wood keep the coals alive which should keep the creosote down plus they sent a new gas burner nozzle with electrode. All of these are nice but it fails to permanently fix the problem. It is hard to work with Central Boiler directly as they want you to work through the distributor that I bought it from.
I paid a little over 13,000 for the unit and I cannot count on the gas to backup the wood.
I have only had it in operation since November 2008 and have worked on it and worked on it. It has been a disaster.
I would like to get my money back and buy just a normal boiler but not sure how to approach that subject. If it would work, I would love to keep it, but this is almost ridiculous. I have asked my distributor for names of others that may have similar problems so that I could contact and possibly find solutions, but they have not and will not provide that info.
Any ideas?
Pat Weeres
Pat:
I do not want to get into the middle of any problems you are having with your wood fired boiler. However, I will be glad to review several choices that you might consider.
1. There is still the chance you may be able to at least turn the boiler back in for some type of partial credit, especially if you made it clear that you were going to be burning only pine and the dealer indicated this was not going to be a problem. A written letter to the manufacturer works far better than an email or phone call. I would make them aware of the problems you are having and include some photos, and explain you are not receiving any assistance from their local rep. At a minimum I would insist on the dealer coming out and checking all the controls and combustion chamber for proper operation.
2. I have a feeling that the written literature on the boiler advised that these were mainly intended for hardwood like oak, which do not have anywhere the problems with creosote buildup that you are experiencing. If this was the case, you might want to offer it for sale on the Internet in like new condition to someone located where hardwood is easier to find.
3. You could install a standard high efficiency propane boiler for “normal” home heating, and leave the wood boiler for when you can get a better mix of wood to burn, or use only for emergencies like when you run out of propane.
I am interested in generating electricity by burning wood. I haven’t seen much about this subject on the website. Why would burning wood be a good choice or a bad choice for generating electricity?
Any information that you could pass along would be much appreciated.
Tyrone
Tyrone:
The reason you have not much about this subject is it is not very practical today. This does not mean it does not work, but 99% of these systems require a wood-fired steam boiler which could explode if not designed and operated properly, it takes constant fire management to maintain proper steam pressure, it takes a good supply of water that is properly tested and treated to reduce chemical buildup inside water tubes, it takes a daily “blow-down” of the mud drum which will fill up with sediment, it takes daily removal of ash, and it takes regular lubrication and adjustment of all the moving parts.
If you check, you will find that almost all of this equipment is refurbished equipment somebody found or saved from the 1930′s and 40′s. Many states require any steam boiler, regardless of use, to be inspected every year by the states safety inspector, and many require that you maintain liability insurance for its use. Many states require steam boilers above a specific size to be operated by a full time boiler operator, and many states require this operator to be a licensed steam plant operator.
In other words, turning firewood into steam is not as simple as you think and is not very cost effective unless you already have the equipment and have lots of time to operate and maintain all the working parts. Most of these systems today are part of a steam show or other event. At one time I had a 20 kW steam driven generator that was new WW2 surplus and it was almost 10 feet tall and weighed 4 tons. It was too big, too heavy, and too much trouble to keep operational so I finally scrapped the whole thing.
Here is a test for you. Put a very large pan on your stove full of water right out of your tap. Now boil it until all of the water has been boiled off, then see how much scale and chemical deposits remain on the sides and bottom of your pan. Now do this 24 hours per day and how long do you think it will take to totally coat the pan with deposits you can’t remove and that reduce heating efficency. Now imagine this was boiler tubing inside a steam boiler to convert water to steam to drive a steam boiler.
We have a wood fired boiler… it is for hot water only – it needs to be replaced. Any idea where I can get a new one? The one we have is about 20 years old… it has a fire box, then the water reservoir on top. It is not used for anything other than heating water.
Thanks
Tina
Tina:
I addressed this question several weeks ago and I am afraid the answer has not changed. Wood-fired domestic hot water heaters are very popular in Mexico but as far as I know, none of these meet our plumbing and boiler codes for safety. I am not saying they are not safe, but there are very strict regulations on the construction, testing, and quality control that must be met and I do not believe any of these have gone through this certification process for (legal) sale in the US. I visited a manufacturer located in Eureka, California about 10 years ago who was making a really good unit, but he moved his operation to Mexico years ago.
The following is a link to unit hand-made by the Amish, but pay attention to the disclaimer note on the ad:
I have a small cabin and I want to build some kind of hot water shower fired by wood, something very simple CAn you lead me in the right direction? It is in the summer only that I will be using it.
Thank you.
Brent
Brent:
All of these wood-fired small hot-water heaters are now only made in Mexico and are hard to import because they do not meet our plumbing and boiler codes. Up until a few years ago there was one small company in Eureka, California that was making these by hand and they were really well built. However, they went out of business in the US and the last I heard they were trying to set up production in Mexico.
Several companies make a small wood-fired hot-water heater to heat an outdoor hot tub and you may be able to use one of these if you can’t find a way to import the model from Mexico. There are many of these wood-fired hot water heaters used in less developed countries.
I have just stumbled upon one of your columns while researching boiler options for our home. It is a 3000 ft2 log and stick frame home in the woods (read: unreliable power), with additional heating for a 1000 ft2 insulated work shop, a few walkways and porte-cochere (snow control only). We have completed extensive renovations and the heating system was upgraded to radiant floor (multiple zones) from an oil-fired scorched air system.
My question goes toward more reliability and longevity than efficiency per se. There is ample fuel in the form of hardwood available, and I don’t mind a little extra of the cut-split-stack routine so a few percentage points in efficiency I can live with assuming there is not a huge increase in particulate emissions. What I would like to avoid, however, is spending a lot of money on a WFHB and have to repeat the process in a few years. I originally looked at models by Central Boiler but have heard many horror stories about their fire boxes being destroyed after 5-7 years, and am leaning more towards ceramic lined ‘gasification’ units such as the Greenwood.
Can you offer any advice in this matter?
Many thanks and best regards,
Tom Tebo
Tom:
The last time I tried to recommend a wood-fired heating system to a reader I had a dealer for corn stoves writing irate email to me for months saying his system was better and I should have included it in my article. Having said that here we go again.
I have a wood-fired hot water boiler that heats my 3400 square foot home that includes a welded steel water jacket around the sides, back, and bottom of the fire-box, plus 90 feet of boiler tubing above the fire-box. Water flows around the fire and is piped back to a hot water coil in my forced air furnace, which distributes the heat to every room. I purchased this unit in 1978 and it was in storage until I built my home in 1993. Although we do not build a fire every night during the winter, we do use it as often as I am home to carry wood and we have never had any problems with burning out the fire-box or water jacket since the water keeps the steel below 200 degrees. We just had our chimney cleaned this past fall for the first time since moving into our solar home in 1994 and the chimney sweep said there was only minor buildup on the interior flue walls.
I have not heard of any major increase in wood-boiler fire-box failures and find this hard to understand unless these failures were related to metal parts not enclosing water and over-heated. Like any marketplace of different products having different features, each manufacturer will say their products are better than the other brands and list all their selling points. I know I would not want any appliance in my home that was burning at over 1100 degrees even with a ceramic lined fire-box, but I understand that these higher temperatures can improve burning efficiency and reduce chimney buildup. Keep in mind you are wanted to heat your home with radiant heated floors and this requires a much “lower” water supply temperature for heating then if you were heating with hot water radiators or hot water coils in a ducted air system.
I am sure almost any of these systems will serve your purpose, so I would select the brand with the best warranty and best installer who will be there if you do have problems. When shopping for any wood stove, I am always interested in how long the fire-box is so I can see how short the wood must be cut, how large the fire-box is so I know how often I have to re-fill it, how are the ashes removed, which is always a pain, and what kind of simple controls are provided to automatically regulate the burning process. I want a wood stove I can fill up and then leave it alone for hours without having to constantly adjust something.
I’m planning a hydronic system using a wood gasification boiler. I found a very efficient boiler that suits me but the problem is it requires a fan that draws 1/3HP all the time and I want to find a way to turn some of the heat into enough electricity to run the fan. I’m off the grid don’t have enough renewable energy to power the fan all the time.
I’ve heard about thermoelectric heater/coolers (as seen in some cheap refrigerators) and understand that they can run the other way, turning a heat difference into electricity.
How about installing a “heat pipe” into the boiler’s gasification chamber to draw out some of the heat to a metal plate outside the boiler, where the thermoelectric device could be mounted? The delta T might be well over 1000-1500 degrees which could make generating a few hundred watts feasible, at least in theory. Have you ever made such a system or have any advice?
Thank you,
Scott Onstott
Scott:
First, the 1/3 HP fan on the boiler sounds really large unless the boiler combustion air path is very restrictive. My entire 3-story 3,400 sq. ft. home only has a single 1/3 HP fan to distribute both heating and cooling air flow to all room registers. See if this was just a motor size they “guessed” at to be safe, or if the boiler actually requires that much fan power. In other words, just having a 1/3 HP fan motor does not mean the fan load requires the full motor horsepower. Also determine how many hours this fan will need to operate each day.
I am very familiar with the thermo-electric systems you are asking about, and I can tell you this is not the way to go. The hardware you would need to power even a much smaller fan motor would be very expensive due to the very limited power output you get. Also, it is not always a good idea sticking other piping into a very hot flue unless the system was specifically designed for doing this.
I would find out more about the fan motor provided with the boiler and its actual power draw (not just nameplate rating). Also ask if this is a high efficiency fan motor. When I was building my solar home, as soon as they delivered my central air handling unit, I removed it from the shipping box and ripped out the fan motor that came with it and replaced it with a super high-efficiency fan motor with a 94% efficiency rating. The longer hours the fan needs to run, the more important this will be.
Finally, if you want to be off grid, the best solution is a small solar power system and batteries to power this fan. If you do not want or need any other AC power, then forget the inverter and replace the fan with a DC motor-driven fan. However, DC motors require motor brush replacement about every 2 years.
I own forest land which I renewable harvest for heating my Alpine house. I am extremely frustrated as I wish to combine a Stirling engine with log-burning to produce green electricity via a generator. Nowhere have I found anything on the domestic scale. Toys and demonstrators and large-scale alternatives seem to exist but not what I seek. I want to be independent and not use fossil fuel for my power requirements. It seems to me that the technology exists and this is such an obvious application I cannot understand the causes of my frustration. Can you help?
John Newson
Julian Alps
Slovenia
John:
You are correct, a Sterling engine-driven electric generator that uses low level heat energy from either burning waste wood or solar thermal energy is a good way to solve your energy needs. Please note that there are many others working in this field even though you may feel frustrated in your search for information. This link will take you to a web site that sells detailed drawings and information on how to build your own 5 HP Sterling engine driven electric generator. This is not a toy or demonstration project.
This link will take you to a British Car Company’s web site describing their new packaged Sterling engine-driven home power-plant that provides both space heating and 15 Kw of electricity for a typical home.
