Is there a Cheaper more basic boiler?
- Thread starter Nickkendall
- Start date
-
Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.
We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.
We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
So your saying I’m best off with just a wood stove not a boiler setup And leave my floor heat to my electic boiler Because I really don’t want a storage system and only need the extra heat for the garage anyways I can heat my house easily with a 9 kw boiler. But got a used 15 kw from a friend but it runs non stop when it’s cold out and still wasn’t sufficient for garage
To close this loop. I am unaware of any small household suitable chip boilers. if you want to heat a school or municipal building there are couple of firms that make them but they are not household units.
Running efficiently at various loads is definitely difficult. It's interesting seeing the changes coming in the last 5 years or so since "owb" gassers (with only 100-300 gallons storage) have become common. From what I'm seeing I think it has finally gotten debugged.
I've burned several models of G series now for 7 years. It modulates some, which reduces cycles. But I think key to minimizing creosote is shutting down super tight while idling. A small air leak can create lots of creosote.
I've burned several models of G series now for 7 years. It modulates some, which reduces cycles. But I think key to minimizing creosote is shutting down super tight while idling. A small air leak can create lots of creosote.
Last edited:
The smallest Chip Boiler I have seen is Chiptec boiler that served the campus of the Society for the Protection of New Hampshire Forests just north of Concord NH. It was a custom job. It was a two component unit, there was a gasifier that generates wood gas and then a standard boiler that used the wood gas to heat hot water. I searched for more info and found this
Background: In 1996, the Forest Society built a heating plant to provide heat to the Conservation Center. Chip – Tec, from Willingston Vermont, was contracted to install a gasifier as part of the hydronic heating system. The gasifier uses green wood chips as a fuel from Henniker Hardwood Pallets (HHP). In 2016, Chip Tec went out of business, leaving no expertise to maintain the biomass boiler and in a study conducted in 2019 by North East Biomass it was determined the gasifier is beyond its useful service life. In addition, HHP decided to move the supply of green wood chips out from under cover, exposing the chips to the weather, such as rain, snow etc. This led to a significant decrease in efficiency at times and often the boiler losing flame. This caused an overreliance on the back up propane boiler. Proposed: Given the stated circumstances, the Forest Society has decided to replace the Chip-Tec with a new biomass boiler. The proposed replacement is a Froling T4-130/150 biomass boiler with the capability to burn Dried Wood Chip (PDC’S) and/or wood pellets. The new boiler would solve the boiler reliability concerns and using either wood pellets or PDC’S would solve the fuel consistency problem. The only remaining problem to address is onsite fuel storage. Because of the limited storage space, about 4 tons, in the existing heat plant, we receive two to three deliveries per week and the delivery charge for the 30-minute commute is close to 75 % of the cost for the green wood chips. The proposed fuel storage silo will have the capacity to store 20 or 25 tons of fuel. Thus enabling a full truck of 14 tons of PDC’S to be delivered while leaving enough in the silo as a cushion. The estimated amount of deliveries will be 6 to 8 per heating season. Froling Energy will deliver the PDC’s from Keene, thus having the cushion will be important
Note they use Precision Dried Wood Chips (PDC) (broken link removed to https://frolingenergy.com/services/wood-chip-fuel/)
These are not the $30 bucks a ton delivered whole tree chips that has sticks and leave and sawdust mixed into wet chips and snow in the winter. I have not seen them in person but my guess is they are somewhere between a standard wood chip and a pellet. My guess is they are bound to Froling for supply as I am not aware of a large number of suppliers of PDCs (then again its not something I look around for). Even the many schools and municipal chip boilers in VT learned long ago that they needed high quality bole tree chips made from the type of wood we burn for firewood or sawmill residuals. They couldn't handle the low grade chips. At least one of the regional suppliers aggressively marketed to schools as a chip broker and they supply a premium chip special for those small systems.
Back when I worked in the pulp mill in Berlin the plant licensed a Weyerhaeuser design for a chip screening and reslicing system. it was a 4 story building full of vibratory screens with chip reslicers and lots of conveyors. We ran 1600 tons a day of wood through it from our chipper which had a 2500 HP electric drive motor. The chips that came out of that plant may not have been dried but they were clean and uniform. My guess is they could be burned as fuel but we had bark boiler that burned anything and the chips were much more valuable to be made into pulp.
Bad LP
Minister of Fire
The entire facility is impressive. They have an entire campus of energy efficient buildings built and designed over a 40 year span. The origin al one is very much early 80s green design (way to many windows and a rotten interior layout optimized for heating) to their last project which looks far more conventional. They use local materials and green materials when they can.
mark cline
Minister of Fire
Here is my 300k boiler , expansion tank and 1500 gallons of storage, plumbed to my 3200 sf log home , all radiant . This is all parts and pieces cobbled together, total rebuild on a 4 yr old boiler and all installation and plumbing done by me , total cost $13000 , if I had somebody install all this and a brand new boiler, $30000 plus . A quality boiler plus storage is not cheap , can’t see the sense of going cheap, it’s not working right or bad design , wet wood , many factors against you. But one big plus is the help, knowledge and expertise from the people on this forum. Can’t thank the individuals enough that helped me take my boiler from good to phenomenal .
Attachments
![[Hearth.com] Is there a Cheaper more basic boiler?](/talk/data/attachments/276/276152-01212441fe43958b8219c1bbd921fa80.jpg?hash=r22eUEA7s8)
I have glycol filled closed system on the underground,house and backup boiler,then a big HX and my wood boiler and 1000 gal storage is water.1000+ gallons of glycol was to much money.
And glycol gets damaged when it is used in a boiler,it basicly gets burnt i was told.My oil boiler doesn't see much use and i have a sidestream filter on the glycol side.
I'm going to be the odd man out. If you have a big slab in your garage and the loops aren't undersized, and you don't care about hitting an exact temp, you don't need water tank storage.
Install a thermostatic mixing valve on the on boiler return to protect it from low temps. Single pump. Keep loading boiler until floor is close to the temp you want. The storage tank is needed if you care about swings in temperature like a living space. If you don't mind your garage being "charged" up to 90-95 F and letting it drop to 50 F over a few days you don't need storage.
Install a thermostatic mixing valve on the on boiler return to protect it from low temps. Single pump. Keep loading boiler until floor is close to the temp you want. The storage tank is needed if you care about swings in temperature like a living space. If you don't mind your garage being "charged" up to 90-95 F and letting it drop to 50 F over a few days you don't need storage.
Lots of parts that have the same labor and time involved, just less material. But a lot of it is low volume of sales. A low volume item that has lots of parts is a tough thing to make money on.
(I'm not a manufacturer, but I've got a few friends who are which is what I'm going by).
There are residential sized chip boilers made, in PEI for example, down into the 40 kW size. A big problem is fuel variability both for chip size/ shape and moisture content. When the size gets down there, the feeding/metering of individual chips becomes critical. If you have fuel that is high moisture, or variable size, or doesn't flow well, the minimum standby firing rates go up to ensure it doesn't go out from the surges/jams, odd bad chip etc.
The woodmizer bio burner dealt with this by having a propane pilot to keep the low fire condition and ignite but I think it had problems and left the market.
There was also some small batch load chip boilers but I think they have all disappeared too. Required storage and manual loading.
The woodmizer bio burner dealt with this by having a propane pilot to keep the low fire condition and ignite but I think it had problems and left the market.
There was also some small batch load chip boilers but I think they have all disappeared too. Required storage and manual loading.
Bad LP
Minister of Fire
Please continue on how this works. What about heat loss in the water as it’s doing it’s job
maple1
Minister of Fire
Bad LP
Minister of Fire
that is very inefficient...
Water has been proven as the best medium for storing BTU's
If you want to wish and hope and hold your breath until a small residential wood chip boiler magically appears on the market have at it but as we have tried to explain, there are technical issues that make it unlikely that you will see such a product. Effectively many companies started with a clean sheet of paper and tried to design such a device and keep coming to the conclusion that the problem was non uniform fuel. Wood chips vary widely in size, shape, fines and moisture content. When dealing with tons of fuel, size and shape is less important but when dealing with ounces it makes a big difference. Moisture content is pretty much directly related to BTU content and the air fuel ratio is closely related to BTU content. Air fuel ratio is based on pounds not density of fuel. Dealing with all that complexity makes for a expensive complex device. Eventually the light bulb went on to make the fuel more consistent by drying it, grinding it then extruding it into pellets. Once the fuel got consistent, than the cost and complexity comes way down. Froling appears to have gone half way on their large institutional boilers where they supply a clean (no fines) pre-dried, consistent chip size but that means the buyer is beholden to Froling to supply those custom chips. Realistically the pellet market has multiple suppliers of standardized pellets so there is a lot to be said to just go with pellets. Note that as the pellet boiler sizes get larger with more complex controls, the quality of the pellet can get lower than what will work on a residential unit. There are commercial pellets made using a blend of agricultural wastes. There have also been attempts to make pellets out of post consumer waste for large units. Talk to any pellet stove user and their number one complaint it usually fuel quality even with pellets that are claimed to be made to Pellet Fuel Institute standards.
Eureka
Feeling the Heat
Well said, pellets and chips are very different animals. Chips bridge, catch on each other (they're "fuzzy"), are not uniform density, and have a lot less btu for the same volume (much larger fuel feed and burner needed). It's complicated.
Comparing to gasoline is even more apples to oranges.
You are missing a fundamental point or you are just in the mood to argue. Gasoline Diesel Natural Gas and propane are standardized products. Yes there is some tolerance but a pound or volume of any of the four yield a number that closely correlates to set BTU content. When the car first starts its doesnt use most of those goodies you mentioned, its "open loop" and looks up fuel settings based on air flow or some surrogate like MAP or in the old days throttle positions. This works as the internal look up table was mapped based on known btu content for the fuel. Once the engine warms up then it goes into closed loop and starts to look at the various downstream sensors for feedback and tunes the engine to maximize efficiency, performance and minimize emissions. So #1 fuel oil ranges from 137,000 to 131,000 btu./lb (HHV) Yes it varies a bit depending on suppliers but the computer can deal with it. Compare that to wood chips, they can range from negative btu value to 8600 btu/lb for bone dry wood. The reason it can be negative is there is so much water, snow or ice that the fuel value is less than the latent heat of fusion (for snow and ice) and the latent heat of vaporization of the water plus the sensible heat that has to carried along with the process in vapor form until dumped out the stack. Even if it does burn, the flame temp is going to be too low for complete combustion which means less heat output and much higher emissions.
BTW I have on occasion in my career had to work to develop ASME test code packages for biomass power plant performance testing on new state of the art $200 to $400 million dollar plants and even they have a tough time dealing with poor fuel quality. I also tune them up on occasion. So I guess if you think you have better way to do it than the industry I guess its time to spend the retirement fund and design something that will work, meets EPA standards and is economically attractive enough for someone to want to have silo next to their house to hold bulk chips.
Inefficient? You already own the slab. You would have 0% standby losses. The purpose of the water it to store/buffer the peak output of the boiler when it exceeds the ability of your heating load to take heat.
If you have a big slab in a work shop and you have a minimum room target temp of say 60 F, and you don't mind it getting as high as say 85 F, it will soak up several burn cycles from a boiler no trouble without the boiler going idle. This doesn't work for a house but fine in a workshop/garage.
If you have a big slab in a work shop and you have a minimum room target temp of say 60 F, and you don't mind it getting as high as say 85 F, it will soak up several burn cycles from a boiler no trouble without the boiler going idle. This doesn't work for a house but fine in a workshop/garage.
I missed one part of that, also need temp control on the discharge to limit to about 120-140 F going into the slab.
It's not complex, think of what OWB's user do to heat shops using in floor heating. They build a fire in boiler, pump the hot water through the floor when they want the space warmer. That's it. They often have no return protection on the OWB hence the massive rotting fire chamber problems they are plagued with.
If your floor is too small or the loops undersized, you couldn't do this without storage as you would keep kicking your boiler into idling. Properly sized loops though you will have plenty of cold return water and never hit the over temp limits on boiler.
It's not complex, think of what OWB's user do to heat shops using in floor heating. They build a fire in boiler, pump the hot water through the floor when they want the space warmer. That's it. They often have no return protection on the OWB hence the massive rotting fire chamber problems they are plagued with.
If your floor is too small or the loops undersized, you couldn't do this without storage as you would keep kicking your boiler into idling. Properly sized loops though you will have plenty of cold return water and never hit the over temp limits on boiler.
You are correct, pellet stoves are fairly popular, they cost aprox. $3,000-$5,000. Pellet boilers are far less common, they cost aprox. $10,000-$15,000. Small scale chip boilers can be purchased and imported from European producers such as Heizomat, but they start around $25,000 which makes them an extremely unpopular option for residential home owners. You can get almost anything you want, if you are willing to spend enough money.
Similar threads
