# Is there a Cheaper more basic boiler?



## Nickkendall (Mar 7, 2021)

I have radiant heat in my house and garage.  We are using a electric boiler currently. I am was planning on adding a new wood stove in the garage to help as garage is connected and fairly large    Then I came accoss the idea of an indoor wood boiler. But there don’t seem to be very many options and what I do find is extremely expensive.  Is there any more basic affordable options or do I just need to stick with a wood stove?   I would love to find a good used one but in North Dakota there is nothing to pick from 
Thanks


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## Nickkendall (Mar 7, 2021)

monteville said:


> Your area has no natural gas service?


No  just propane. And I am hoping to stay away from it as I see it’s price rising with gas


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## andym (Mar 7, 2021)

Indoor boiler systems with storage are not cheap. There are some lesser known brands that are not EPA certified that can be bought for half price or less. That's a pretty controversial subject around here though. The storage aspect will still usually run a couple grand as well. A regular wood stove supplemented with a propane or NG boiler would definitely be a good economical option.


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## andym (Mar 7, 2021)

monteville said:


> with storage of what? firewood? chips ? pellets?


Thermal storage. Most indoor boilers are connected to large insulated water tanks. The boiler heats the tank, the water from the tank heats your house. Others (who actually own boilers) will be along soon to explain more in detail. 
I too looked into boilers a year ago, but decided against it also because of the $$ involved. I was not set up with radiant heating however. Had that been the case I may have bit the bullet and went that route.


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## maple1 (Mar 8, 2021)

Are you sure you are ok to burn wood in your garage? Most insurance companies, that is a big no no.


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## Nickkendall (Mar 8, 2021)

maple1 said:


> Are you sure you are ok to burn wood in your garage? Most insurance companies, that is a big no no.


Yea I for the ok from Insurance agent


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## Nickkendall (Mar 8, 2021)

andym said:


> Indoor boiler systems with storage are not cheap. There are some lesser known brands that are not EPA certified that can be bought for half price or less. That's a pretty controversial subject around here though. The storage aspect will still usually run a couple grand as well. A regular wood stove supplemented with a propane or NG boiler would definitely be a good economical option.


I have no problem with a non certified boiler I’m not going to be using it all the time just occasionally when it’s really cold    
what are some options?


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## Bad LP (Mar 8, 2021)

Describe affordable in your own terms.


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## peakbagger (Mar 8, 2021)

Indoor wood boilers are complex systems that need to be customized for the house.  Anyone buying a house with a system can have a tough time learning the system in enough detail to successfully run it. New owners also tend to have not learned the lesson on seasoned wood and try to burn green wood and have potential creosote issues. Finally some systems had compromises in their components particularly hot water storage tanks that can lead to stopping the use of a system. Many storage tanks were moved into place with no provisions for removal, if the tank fails the system is not easily repairable. Some folks eventually just decide that the hassle involved with burning wood is not worth it and just stop using them. Therefore good wood boilers pop up on occasion for sale used for cheap where the current owner wants them gone. If you have the rigging skills and the installation skills you end up with a quality unit for low cost and then can spend some of the savings on upgrading the poor quality components.


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## Nickkendall (Mar 8, 2021)

peakbagger said:


> Indoor wood boilers are complex systems that need to be customized for the house.  Anyone buying a house with a system can have a tough time learning the system in enough detail to successfully run it. New owners also tend to have not learned the lesson on seasoned wood and try to burn green wood and have potential creosote issues. Finally some systems had compromises in their components particularly hot water storage tanks that can lead to stopping the use of a system. Many storage tanks were moved into place with no provisions for removal, if the tank fails the system is not easily repairable. Some folks eventually just decide that the hassle involved with burning wood is not worth it and just stop using them. Therefore good wood boilers pop up on occasion for sale used for cheap where the current owner wants them gone. If you have the rigging skills and the installation skills you end up with a quality unit for low cost and then can spend some of the savings on upgrading the poor quality components.


Great I am seeing that a wood boiler cost way more then a propane or electic     I love to do stuff myself and would like to find a good used one    Only thing is I don’t see any used indoor boilers for sale  lots of outdoors     
Does a boiler have to have a storage tank of could it be just tied into existing system and it’s only heats the fluid as it passes though. And when it’s not being run the electric would do the work
Thanks


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## peakbagger (Mar 8, 2021)

Do not waste your time on an indoor wood boiler system without proper thermal storage. 500 to 1000 gallons minimum. It effectively acquires the bad attributes of an outdoor boiler (lots more wood consumption and lots more creosote). Storage means the indoor boiler is run at its most efficient operating point for several hours and then  shut down so it never idles.


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## Bad LP (Mar 8, 2021)

Indoor boilers become available but having the local enough is an issue. Mine was used that came from Eastern NY, parked it in MA for a couple of weeks and then I transported it to Northern Maine. 13 or so hours total time of travel. 
The seller was found here on Hearth and his addition forced the sale (or at least that was the story) I was not interested in an open system so I did not buy his AST tank, coil or his power loss over heat protection. 
That left me with buying new ASME rated tanks and building the protection on my joists near the boiler as well as an insulated room housing the tanks. 
The boiler was relativity a newer model for about 50% off retail. It was borderline on sizing so I burn a little more than estimated so I end up having multiple hot reloads  when it's really cold. 

I personally would not own an outdoor unit but that's me.


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## clancey (Mar 8, 2021)

This might be stupid but it worth asking for me..I have copper piping in my basement area and those pipes extends up into my house along the side of the walls would this be considered hot water heater or do I have a boiler somewhere down there heating my house like would it be a boiler or a furnace or hot water heat what do I call it..What in the world is Boiler wood heat like your mentioning and why the big fuss about it .. Would not it be hot water heat or something like I have??? clancey


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## Bad LP (Mar 8, 2021)

clancey said:


> This might be stupid but it worth asking for me..I have copper piping in my basement area and those pipes extends up into my house along the side of the walls would this be considered hot water heater or do I have a boiler somewhere down there heating my house like would it be a boiler or a furnace or hot water heat what do I call it..What in the world is Boiler wood heat like your mentioning and why the big fuss about it .. Would not it be hot water heat or something like I have??? clancey


You have something making hot water that feeds the piping hot water that is keeping you warm. 
Best to Google Tarm Biomass to see how a wood boiler works. Pictures are worth a million words sometimes. There are other websites as well like Smokeless Heat. Smokeless was very helpful and made it to my very short list of companies. In fact the list was reduced to 2 companies and saving a fist full of money was in my favor and that don't happen very often.


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## clancey (Mar 8, 2021)

Thanks I"ll do some checking...clancey


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## brenndatomu (Mar 8, 2021)

Bad LP said:


> Mine was used that came from Eastern NY, parked it in MA for a couple of weeks and then I transported it to Northern Maine. 13 or so hours total time of travel.


I made a 16 hour round trip to Wisconsin for my Kuuma furnace (that was just travel time...made a weekend out of it actually)


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## cumminstinkerer (Mar 8, 2021)

I made a ten hour trip to SE Wisconsin for my used Econoburn, another member had it and offered it to me at a great price, I also made a weekend out of it since I have family 40 minutes from the other member.


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## Nickkendall (Mar 8, 2021)

So if I had a wood boiler to be efficient I would need also storage tanks?       Who has made there own setup of tubing something that heats water  close by a wood stove  just using that in addition to regular boiler?  When the wood stove is burning it is adding some heat to the floor system  when it’s not the floor is heated with its electric boiler?


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## Nickkendall (Mar 8, 2021)

After watching the old tarm video makes. E want one of them   But I guessing there are few and far between?  And I still should have storage     Can storage tanks be added on a closed loop glycol filled system?


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## 3fordasho (Mar 8, 2021)

Nickkendall said:


> I have no problem with a non certified boiler I’m not going to be using it all the time just occasionally when it’s really cold
> what are some options?


I'd look at an Attack, Biomass or EKO from newhorizonstore.com if they are still available.  All downdraft european gassers so they are efficient and clean burning but will not have US EPA certification.   I am happy with my Attack 45K with the lamba option but it cost me about $6K for just the boiler.  I have $400 into my two scrap 500gallon propane tanks for heat storage but lots of time to clean them out and drill and weld on the proper fittings.
Probably another $3k in pumps, fittings, expansion, copper tubing, heat emitters,  spray in trench underground lines etc, etc.  You'll save a bit if everything is in the same building. (no underground lines).   You won't find any of these boilers used in North Dakota, maybe if you were out east.  I'm in MN and the only thing that comes up used is the occasional conventional indoor boiler (old) and they're not worth it IMHO due to in-efficiency and the amount of reloading they will require.


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## peakbagger (Mar 8, 2021)

Nickkendall said:


> After watching the old tarm video makes. E want one of them   But I guessing there are few and far between?  And I still should have storage     Can storage tanks be added on a closed loop glycol filled system?



My neighbor is the poster child for not using storage with Tarm indoor wood boiler. He had too many chimney fire to count and then melted a stainless steel liner. 

I have friend that has heated his house for 25 years using coil on wood stove. He has several safety systems to make sure he does not boil the coil or run it dry. He also has dump zone to dump excess heat. It can be done but requires some knowledge of controls and systems sop that its fool resistant.  he has an oil boiler but only one flue os he has baseboards

A closed loop gycol system is best tied to unpressurized hot water storage tank. American Solar Technics, owned by Hearth.com member (Tom in Maine) is the maunfacturer. The tank would be filled with water and would be heated by a coil filled with glycol instead of water. Things would get far trickier with pressurized tank unless you want to buy 500 gallons of glycol


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## HardDrinkin'Lincoln (Mar 8, 2021)

You can check out my Velodlux Lambda 350 boiler project here. 

https://www.hearth.com/talk/threads/my-first-winter-with-a-new-vedolux-350.180481/

Like you I already have radiant heat in the house. The 500 gallon storage tank resides in my insulated garage and heat loss from the tank keeps the garage comfortable all winter.


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## brenndatomu (Mar 8, 2021)

monteville said:


> Storage don't solve the root cause.


Sure it does...boiler goes from zero to 100% in a couple minutes...runs at 100% until the fire is over.


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## Bad LP (Mar 8, 2021)

peakbagger said:


> My neighbor is the poster child for not using storage with Tarm indoor wood boiler. He had too many chimney fire to count and then melted a stainless steel liner.
> 
> I have friend that has heated his house for 25 years using coil on wood stove. He has several safety systems to make sure he does not boil the coil or run it dry. He also has dump zone to dump excess heat. It can be done but requires some knowledge of controls and systems sop that its fool resistant.  he has an oil boiler but only one flue os he has baseboards
> 
> A closed loop gycol system is best tied to unpressurized hot water storage tank. American Solar Technics, owned by Hearth.com member (Tom in Maine) is the maunfacturer. The tank would be filled with water and would be heated by a coil filled with glycol instead of water. Things would get far trickier with pressurized tank unless you want to buy 500 gallons of glycol


500 gallon$ of crap eating your part$. YIKES


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## Bad LP (Mar 8, 2021)

monteville said:


> Storage don't solve the root cause.



It most certainly does. If you are getting creosote you have major problems that need to be resolved... yesterday.


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## peakbagger (Mar 8, 2021)

monteville said:


> Wood is not like natural gas that can be easily turned on and off, when you turn down a wood fire, it will smolder and generate creosote.
> Storage don't solve the root cause.
> I believe the ultimate solution is a wood burner that can efficiently output any power between 0 and MAX BTU.


Yup its called a pellet boiler ;


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## Nickkendall (Mar 8, 2021)

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


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## Nickkendall (Mar 8, 2021)

I don’t want a chip or pellet boiler


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## peakbagger (Mar 8, 2021)

monteville said:


> What about a chip boiler? Can chip boilers do the same as pellet boiler?


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.


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## E Yoder (Mar 9, 2021)

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.


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## E Yoder (Mar 9, 2021)

I agree, no small chip boilers out there. Just not feasible.


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## peakbagger (Mar 9, 2021)

E Yoder said:


> I agree, no small chip boilers out there. Just not feasible.


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) Precision Dry Wood Chip Fuel Producer & Supplier • Froling Energy 

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.


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## Bad LP (Mar 9, 2021)

peakbagger said:


> 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 _
> 
> ...


That sounds like an awesome operation.


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## peakbagger (Mar 9, 2021)

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.


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## mark cline (Mar 9, 2021)

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 .


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## salecker (Mar 9, 2021)

Nickkendall said:


> I have no problem with a non certified boiler I’m not going to be using it all the time just occasionally when it’s really cold
> what are some options?
> [/





Nickkendall said:


> After watching the old tarm video makes. E want one of them   But I guessing there are few and far between?  And I still should have storage     Can storage tanks be added on a closed loop glycol filled system?


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.


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## slowzuki (Mar 9, 2021)

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.


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## E Yoder (Mar 9, 2021)

monteville said:


> Why are small chip boilers not feasible? Is there a component that cannot be made small, or cannot be efficiently made small?


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).


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## slowzuki (Mar 9, 2021)

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.



monteville said:


> Why are small chip boilers not feasible? Is there a component that cannot be made small, or cannot be efficiently made small?


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## Bad LP (Mar 9, 2021)

slowzuki said:


> 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.


Please continue on how this works. What about heat loss in the water as it’s doing it’s job


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## maple1 (Mar 10, 2021)

Bad LP said:


> Please continue on how this works. What about heat loss in the water as it’s doing it’s job



That's likely where not caring about hitting a certain temp comes in.


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## Bad LP (Mar 10, 2021)

maple1 said:


> That's likely where not caring about hitting a certain temp comes in.


If I don’t care why am I heating it at all?


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## salecker (Mar 10, 2021)

slowzuki said:


> 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.


that is very inefficient...
Water has been proven as the best medium for storing  BTU's


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## peakbagger (Mar 11, 2021)

monteville said:


> Pellet stoves have sold very well, so why not small chip boilers? Small chip boilers = pellet stove (replace pellet auger with chip auger) + firebox insulation + boiler coils + circulation pump, right?


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.


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## Eureka (Mar 11, 2021)

Bad LP said:


> Please continue on how this works. What about heat loss in the water as it’s doing it’s job


Might as well skip the stove and just build a fire on the floor using this logic.


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## E Yoder (Mar 11, 2021)

peakbagger said:


> 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.


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.


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## peakbagger (Mar 11, 2021)

monteville said:


> The automotive industry already have mature solutions of fuel/air ratio: MAF sensor + intake air temperature sensor + exhaust O2 sensor + ECU control of throttle and injection. A simple system cost less than $100 if mass produced.
> 
> The control algorithm use a short term fuel trim and a long term fuel trim to separately accommodate to fluctuations due to engine operating condition, and refill of the fuel tank.


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.


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## slowzuki (Mar 11, 2021)

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.



salecker said:


> that is very inefficient...
> Water has been proven as the best medium for storing  BTU's


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## slowzuki (Mar 11, 2021)

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.



Bad LP said:


> Please continue on how this works. What about heat loss in the water as it’s doing it’s job


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## S.Whiplash (Mar 11, 2021)

monteville said:


> Pellet stoves have sold very well, so why not small chip boilers? Small chip boilers = pellet stove (replace pellet auger with chip auger) + firebox insulation + boiler coils + circulation pump, right?



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.


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## Brokenstone (Mar 13, 2021)

Regarding comparing the slab to water as a thermal reservoir. A slab will lose stored heat much faster. It has much more surface area than a vessel. It is in contact with a colder mass throughout it's greater surface area.
Its not as thermaly dense as water and can store less heat.

A water vessel will store heat longer than a slab will and be able to transfer heat long after a slab is unable to because there is none.


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## hyfire (Mar 13, 2021)

Mbtek makes a non certified boiler,  and some people say good things about them for the price, you could buy 3 of them vs a brand name boiler on the market. .  I heard customer service is not great, but talked to a few owners, no real complaints just some settings issues.   Deliver time is about 2-3 months. Its not a complicated unit  and looks simple to clean for the trade off of not being so efficient.  10 year warranty and 5mm thick steel makes them pretty heavy duty.


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## Eureka (Mar 14, 2021)

A slab does not store heat in any way.  It distributes and releases it, constantly, and uncontrollably.


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## hyfire (Mar 14, 2021)

Pellets cost more than wood ,unless you got a super deal buying them your going to have no cost savings.


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## Highbeam (Mar 14, 2021)

Eureka said:


> A slab does not store heat in any way.  It distributes and releases it, constantly, and uncontrollably.



I must disagree. As an owner of an insulated 1800 sf slab it absolutely absorbs heat and releases it slowly. There is a huge flywheel effect. Now, is it as good as an insulated 1000 gallon water tank? No. But it is obvious  that the thermal mass of a slab is not zero.


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## slowzuki (Mar 15, 2021)

Didn't double check the math but a workable 15 C swing in my 32x24ft slab looked to be same energy as a 40 C swing in a 520 gal tank.

Edit, for example, when I brought my boiler online, it took 2 days continuous firing to bring the return water temperature from the slab up to the target temp.



Highbeam said:


> I must disagree. As an owner of an insulated 1800 sf slab it absolutely absorbs heat and releases it slowly. There is a huge flywheel effect. Now, is it as good as an insulated 1000 gallon water tank? No. But it is obvious  that the thermal mass of a slab is not zero.


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## slowzuki (Mar 15, 2021)

They do store heat, a lot of heat, but yes they release it non-stop at a steady and predictable rate into the space.  Predictable enough that you can plan a firing schedule around keeping it a reasonably steady temperature.  Again, this is not ideal for a house, works fine in a shop.



Eureka said:


> A slab does not store heat in any way.  It distributes and releases it, constantly, and uncontrollably.


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## maple1 (Mar 15, 2021)

Highbeam said:


> I must disagree. As an owner of an insulated 1800 sf slab it absolutely absorbs heat and releases it slowly. There is a huge flywheel effect. Now, is it as good as an insulated 1000 gallon water tank? No. But it is obvious  that the thermal mass of a slab is not zero.



Agreed.


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## hyfire (Mar 16, 2021)

Lets not worry about the slab, I would be more worried about finding a boiler.  Go to the mbtek site and start talking to some stove users get some info before you buy anything! Newhoirzonstore has a great selection of european boilers. A froling boiler will be 10-14 k.  Or check autom boilers in Quebec about  8-9 k for a csa gassifier.


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## NateB (Mar 17, 2021)

Nickkendall said:


> After watching the old tarm video makes. E want one of them   But I guessing there are few and far between?  And I still should have storage     Can storage tanks be added on a closed loop glycol filled system?


Consider an Eko with unpresserized storages from Tom in maine. American solartecnics.  You can make your DHW, and supplement your heat.  Then in the summer you can dehumidify and cool your garage while heating your DHW with a air source heat pump on your storage.


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## maple1 (Mar 17, 2021)

hyfire said:


> Lets not worry about the slab, I would be more worried about finding a boiler.  Go to the mbtek site and start talking to some stove users get some info before you buy anything! Newhoirzonstore has a great selection of european boilers. A froling boiler will be 10-14 k.  Or check autom boilers in Quebec about  8-9 k for a csa gassifier.



Have more info on the autom thing? Google found nothing.


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## S.Whiplash (Mar 17, 2021)

hyfire said:


> Pellets cost more than wood ,unless you got a super deal buying them your going to have no cost savings.



That's a bit of a blanket statement, pellets do cost more than wood, but harvesting wood is not free, a significant investment in time and equipment is needed.  Directly comparing the cost of wood pellets to fossil fuels per BTU output, they are currently cheaper than oil and propane, but more expensive than  N.G.


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## hyfire (Mar 17, 2021)

maple1 said:


> Have more info on the autom thing? Google found nothing.


Sorry made a typo they are called Autonom!
https://autonomboilers.com/product-category/boilers/


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## hyfire (Mar 17, 2021)

S.Whiplash said:


> That's a bit of a blanket statement, pellets do cost more than wood, but harvesting wood is not free, a significant investment in time and equipment is needed.  Directly comparing the cost of wood pellets to fossil fuels per BTU output, they are currently cheaper than oil and propane, but more expensive than  N.G.


I used to go through 2 bags a day with tax thats $14  worth,. You do a have a point depends  what your paying for wood how much is a face cord of wood in equivalent of pellet bags?


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## Bad LP (Mar 17, 2021)

hyfire said:


> I used to go through 2 bags a day with tax thats $14  worth,. You do a have a point depends  what your paying for wood how much is a face cord of wood in equivalent of pellet bags?


Get away from the face cord BS and go to the standard cord of 4x4x8 feet and then run the numbers.


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## hyfire (Mar 17, 2021)

Bad LP said:


> Get away from the face cord BS and go to the standard cord of 4x4x8 feet and then run the numbers.


Comes out to $400 to a cord of wood at 7$ a bag. Wood is around 300 a cord delivered.


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## Bad LP (Mar 18, 2021)

hyfire said:


> Comes out to $400 to a cord of wood at 7$ a bag. Wood is around 300 a cord delivered.


I was not seeing that 400 last I noticed in Maine but I honestly don’t know today’s numbers. I was seeing 230-250/pallet and that is close to what my wood guy delivered my last order @ 230/cord. He had to raise his numbers because his permit cost from the paper company went up.


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## slowzuki (Mar 18, 2021)

Firewood cost always hard to figure.  My free firewood rapidly climbs in cost when contemplating a processor to make it less hassle or better storage to keep it under cover.


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## Highbeam (Mar 18, 2021)

I expect cord wood to be cheaper as a fuel because it’s not a manufactured product. Lots of middle men making profits.


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## hyfire (Mar 18, 2021)

Sorry my number are in Canadian dollars?Does it make more sense now?


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## S.Whiplash (Mar 18, 2021)

hyfire said:


> I used to go through 2 bags a day with tax thats $14  worth,. You do a have a point depends  what your paying for wood how much is a face cord of wood in equivalent of pellet bags?




A ton of wood pellets can be purchased for aprox. $200, that brings down the cost of each 40 lb. bag to around $4.00.  A bag of soft-wood pellets contains aprox. 8,000 BTU the equivalent of  2.5 gallons of heating oil or 3.75 gals. of propane.  The wood comparison would depend on the species and moisture content but a ton of pellets can be stored in 30% of the space a ton of cordwood can due to higher desnity.


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## hyfire (Mar 18, 2021)

I based my data on 8500 btu per lb of pellets and an average of 20 Million btu for a full cord of wood, which is very conserative.  The price in Canada is way more than in the USA for the pellets. I still say if  you have the room the  normal wood is better since you can burn any wood you can get , which is easier usually than pellets.


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