Question on Lambda

[Eric Johnson]

I'll be relocating to Wisconsin in a couple of years and will need to set up a new gasification system. I'm currently running an EKO 60 and think it's a fine boiler, but it looks to be discontinued in this country. I'd think about getting a Biomass, but figure maybe it pays to go top shelf with a lambda system. (Not interested in a Garn, as good as they are, so don't bother trying to convince me to buy one).

I haven't really done much research but I see that AHONA sells the Vigas 60 with lambda control, and Tarm sells the lambda Froeling, but only a 20-30 kw model, according to the website. Neither offers prices, so I'm curious about that as well. Also curious about the advantages of the lambda sensor vs no lambda. Any other rigs I should be looking at?

I'll be burning very dry oak and locust with 1,500 gallons of pressurized storage.

Any and all thoughts and other suggestions are welcome.

 

[Brialin]

I'll be relocating to Wisconsin in a couple of years and will need to set up a new gasification system. I'm currently running an EKO 60 and think it's a fine boiler, but it looks to be discontinued in this country. I'd think about getting a Biomass, but figure maybe it pays to go top shelf with a lambda system. (Not interested in a Garn, as good as they are, so don't bother trying to convince me to buy one).

I haven't really done much research but I see that AHONA sells the Vigas 60 with lambda control, and Tarm sells the lambda Froeling, but only a 20-30 kw model, according to the website. Neither offers prices, so I'm curious about that as well. Also curious about the advantages of the lambda sensor vs no lambda. Any other rigs I should be looking at?

I'll be burning very dry oak and locust with 1,500 gallons of pressurized storage.

Any and all thoughts and other suggestions are welcome.

I have a vias 40 which is 3 years old. Had a tarm gasifier for 17 years before this. I wasn't sure about the lambda controls but everything is going computerized now. I probably use 25 percent less wood. Wish to tarm died years ago. I had to replace the refractory nozzle every year at a cost of $500. I have not had to replace the nozzle on the vigas or do anything to it. Best investment ever made.

 

[jebatty]

Surprised to see the need to replace the Tarm nozzle so oftern. In the middle of year 10 with my Tarm Solo Plus 40, and the nozzle and other refractory still in good condition.

 

[JohnDolz]

I'll be relocating to Wisconsin in a couple of years and will need to set up a new gasification system. I'm currently running an EKO 60 and think it's a fine boiler, but it looks to be discontinued in this country. I'd think about getting a Biomass, but figure maybe it pays to go top shelf with a lambda system. (Not interested in a Garn, as good as they are, so don't bother trying to convince me to buy one).

I haven't really done much research but I see that AHONA sells the Vigas 60 with lambda control, and Tarm sells the lambda Froeling, but only a 20-30 kw model, according to the website. Neither offers prices, so I'm curious about that as well. Also curious about the advantages of the lambda sensor vs no lambda. Any other rigs I should be looking at?

I'll be burning very dry oak and locust with 1,500 gallons of pressurized storage.

Any and all thoughts and other suggestions are welcome.

For me the Lamda enables load it and forget it with maximum efficiency. The group is probably bored on my posts about the Effecta but I love it. If you search Effecta or my posts you will find a lot of background.

 

[velvetfoot]

Did I read that AHONA will also be selling Effectas? I can vouch how easy they are to fire, having just seen John's!

 

[goosegunner]

Not a plug for Effecta because I have never even seen one, but the pellet burner add on option sure looks intriguing for times when I am gone.

What area of Wisconsin?

gg

 

[__dan]

If it were me building new, first on my list would be a contiguous wrap of the concrete foundation with 2" to 4" rigid foam board similar to the European Passivhaus standard, with radiant heat in the basement slab for storage or thermal flywheel. What I have now is 2" under the slab and exterior to the foundation walls. It works perfectly.

If the lambda is built in to the boiler, it is not an expensive adder compared to trying to add it to a boiler without it. You would not reject it to save money if the boiler offers both options. Then you look at the added cost spread out over the life of the boiler. I'm guessing it's a ~ $2000 adder or $100 annually over 20 years. In that case the lambda will be saving you more than $100 annual of your own labor to just load the fuel and walk away. The savings may be minimal in fuel but certainly significant in saving labor, operator's time.

If you're running HW radiant and using the basement slab for storage, you could probably trade off that for a smaller storage tank. So you would have a savings of smaller storage tank and running the radiant storage/distribution on OAT reset, lower HW temp, the boiler would achieve HWS setpoint earlier and turn down, which the lambda Froling does in auto.

My slabs run 85 to 90 F in January after the heat has penetrated evenly and if it's 40 F out, I don't have to fire the boiler for two or three days, for heat, I might have to fire it to get my fire making fix. If it's 40 F out and I fire the boiler, I will crack a window in January.

The combination of the Froling with turndown and the basement slab for storage is what made my system. I would surely have a constant problem with an alternate boiler without a turndown. My only variable on the next build would be pellet or cordwood.

 

[JohnDolz]

If it were me building new, first on my list would be a contiguous wrap of the concrete foundation with 2" to 4" rigid foam board similar to the European Passivhaus standard, with radiant heat in the basement slab for storage or thermal flywheel. What I have now is 2" under the slab and exterior to the foundation walls. It works perfectly.

If the lambda is built in to the boiler, it is not an expensive adder compared to trying to add it to a boiler without it. You would not reject it to save money if the boiler offers both options. Then you look at the added cost spread out over the life of the boiler. I'm guessing it's a ~ $2000 adder or $100 annually over 20 years. In that case the lambda will be saving you more than $100 annual of your own labor to just load the fuel and walk away. The savings may be minimal in fuel but certainly significant in saving labor, operator's time.

If you're running HW radiant and using the basement slab for storage, you could probably trade off that for a smaller storage tank. So you would have a savings of smaller storage tank and running the radiant storage/distribution on OAT reset, lower HW temp, the boiler would achieve HWS setpoint earlier and turn down, which the lambda Froling does in auto.

My slabs run 85 to 90 F in January after the heat has penetrated evenly and if it's 40 F out, I don't have to fire the boiler for two or three days, for heat, I might have to fire it to get my fire making fix. If it's 40 F out and I fire the boiler, I will crack a window in January.

The combination of the Froling with turndown and the basement slab for storage is what made my system. I would surely have a constant problem with an alternate boiler without a turndown. My only variable on the next build would be pellet or cordwood.

Good stuff! I would agree that infrastructure should be given the first thought. When all is said and done replacing the boiler (if needed) would be much cheaper than changing the infrastructure.

Dan - I am not sure if efficiency improve or drop with the turndown feature, I will leave that to the data guys but I believe there is another way to achieve success in what you are doing. I tried to read about the turndown but didn't really find anything on it - I am also assuming that you have other types of emitters in your house.

To heat the slab - you can also use a mixing valve (or other device) to run perfect design temp water through your slab, I believe greenhouses do this all of the time. You may already be doing this but I couldn't tell from your post. Using this low temp mix (there is a long thread on this topic) allows you to get more overall use out of you tanks.

Then assuming you have other types of emitters in the house, you will most likely have a different design temperature for those. There are boilers that have integrated technology that accommodate for different design temperature for different zones (European houses usually have only 1 or 2 zones so if you have/want multiple zones you would ideally tie them into 2 main zones at the boiler). For example my Effecta boiler has the ability to control 2 (maybe more - I forget) shunt/mixing valves plus a 3rd one for DHW. With this you can run the boiler at maximum efficiency and always have the ideal design temp for your slab, house emitters and DHW. I'm not suggesting that Effecta is the only one that can do this, it is the only one that I am familiar with.

 

[JohnDolz]

Did I read that AHONA will also be selling Effectas? I can vouch how easy they are to fire, having just seen John's!

Karl - it was a pleasure meeting you. hanks for making the trip down, I hope the coffee was worth the drive. I look forward to seeing your operation.

 

[Karl_northwind]

Welcome to WI. With the Very dry oak and locust, I'd certainly think about a lambda control. we have a number of effecta's running in Wi at this point, and they've been pretty good, once you get people up to speed on dry wood (you're the choir) the main issues have been keeping things clean (the 02 sensor and the fan area) and the cost.
We're dealing with Heatmaster G series boilers mostly at this point, with some GARN's thrown in. Heatmaster is willing to spec, build and ship buffer tanks for us if we need (409 stainless and really good pricing). We've put a handful of them in, and they certainly seem to be "set it and forget it" mostly because they are not lambda, but still have really good emissions and efficiency numbers, and a price that I can sell them at.

What part of the state are you headed for? we all know the boiler world is changing here in the US, so if it's a couple years out, don't plan too far out.

karl

 

[Tennman]

Eric, I have no regrets purchasing the BioMass and still believe for someone like myself who had no idea whether we could live with a wood boiler it's an excellent entry level choice. Last year I decided to step up a level to something less time and skill demanding because of age and travel. Now as a more experienced operator I'd never purchase an entry level boiler because the value of my time is going up faster than the price of mid to top level boilers. Absolutely agree with _dan in terms of spreading the additional cost spread over 10-15 years versus the convenience and pleasure of tending something smarter and more friendly. I spent some money last year to buy some operational luxury and it's been worth every penny.

 

[BoiledOver]

I'll be relocating to Wisconsin in a couple of years and will need to set up a new gasification system.

I'll be burning very dry oak and locust with 1,500 gallons of pressurized storage.

Any and all thoughts and other suggestions are welcome.

The Lopper looks to be a well built unit, a bit spendy though. As you can see in their literature, they offer regular and heavy duty. Thicker steel on the HD.

https://www.hearth.com/talk/threads/long-time-coming-installed-a-lopper-drummer-45-boiler.121101/

http://www.loppernorthamerica.com/

 

[__dan]

To heat the slab - you can also use a mixing valve (or other device) to run perfect design temp water through your slab, I believe greenhouses do this all of the time. You may already be doing this but I couldn't tell from your post. Using this low temp mix (there is a long thread on this topic) allows you to get more overall use out of you tanks.

House is radiant only with an indirect DHW. Two Tekmar OAT reset injection pump controllers, one for the WM Gold oil boiler and one for the Froling, controlling their variable speed mixing pump. The controllers were $80 each new on fleabay, normally $500 each.

This years fuel budget was two piles (~ 3 cord total) of primo seasoned red and white oak plus the annual debris from cleaning the yard. I've burned most of the debris and 3/4 of the first pile, not touched or looked at the second pile. First year burning the better cared for oak from 2011.

I don't see how my fuel consumption could be lower. I guess ~ 3 cord annual heat and DHW, cord wood only, no oil.

I don't have any numbers for tank vs slab for storage but the slab works. Remember, you are charging the slab at 130 F, never more, and it sits there passively giving back its heat. Slab temp peaks ~ 90 F, probably drops to ~ 72 F with no heat for two weeks.. The DHW tank holds 40 G overnight no problem. If I need more than 40 G DHW I would have to fire the boiler, which I miss if I go too long without making a fire.

Basement slab circ and injection mixing pump are slaved to the boiler pump. System is not complete, just working, so in the summer I manually disable the slab and control / avoid slumbering by only loading enough fuel for the DHW tank, which is ~ a 2 gallon pail of twigs and branches. Literally, as accurate as I can be.

So if I want heat I put wood in and if not, I don't. It works exactly as I hoped for.

My guess is the slab performs on par or better than a tank for storage but the combination of the two is what I would plan for / advise. This is for a very well insulated modern construction home.

One of the surprises of the system was how much I enjoy making a fire.

The system is plumbed for a storage tank but that stops at the tap.

https://www.hearth.com/talk/threads/a-few-pictures-of-our-boiler-systems.75006/page-6#post-1323574

 

[JohnDolz]

House is radiant only with an indirect DHW. Two Tekmar OAT reset injection pump controllers, one for the WM Gold oil boiler and one for the Froling, controlling their variable speed mixing pump. The controllers were $80 each new on fleabay, normally $500 each.

This years fuel budget was two piles (~ 3 cord total) of primo seasoned red and white oak plus the annual debris from cleaning the yard. I've burned most of the debris and 3/4 of the first pile, not touched or looked at the second pile. First year burning the better cared for oak from 2011.

I don't see how my fuel consumption could be lower. I guess ~ 3 cord annual heat and DHW, cord wood only, no oil.

I don't have any numbers for tank vs slab for storage but the slab works. Remember, you are charging the slab at 130 F, never more, and it sits there passively giving back its heat. Slab temp peaks ~ 90 F, probably drops to ~ 72 F with no heat for two weeks.. The DHW tank holds 40 G overnight no problem. If I need more than 40 G DHW I would have to fire the boiler, which I miss if I go too long without making a fire.

Basement slab circ and injection mixing pump are slaved to the boiler pump. System is not complete, just working, so in the summer I manually disable the slab and control / avoid slumbering by only loading enough fuel for the DHW tank, which is ~ a 2 gallon pail of twigs and branches. Literally, as accurate as I can be.

So if I want heat I put wood in and if not, I don't. It works exactly as I hoped for.

My guess is the slab performs on par or better than a tank for storage but the combination of the two is what I would plan for / advise. This is for a very well insulated modern construction home.

One of the surprises of the system was how much I enjoy making a fire.

The system is plumbed for a storage tank but that stops at the tap.

https://www.hearth.com/talk/threads/a-few-pictures-of-our-boiler-systems.75006/page-6#post-1323574

View attachment 173351 View attachment 173352

 

[JohnDolz]

Thanks for the extra info, I find I am constantly learning tons here. Based on this I assume the turndown feature is used in conjunction with your injector pump to keep you storage/slab in the target zone, correct? I imagine if you ran flat out all of the time you could gain efficiency on the wood but at 3 cord what difference would it make?

I believe most situations will have a slab (or not) plus other emitters. Whether someone uses injection pumps or mixing valves there would need to be some type of controller to target the different design temps. I liked the Effecta because for me, a VERY low tech guy, it is basically 1 stop shopping.

I'll be curious to hear if you gain some efficiency once you install the tank (I'm guessing at that point you will run the Froling flat out and use the injector pump deliver water to the slab). I definitely agree if someone can have a radiant and slab combined with injector pumps or mixing valves tied to ODR they will be on top of their game.

Funny you mention about liking to start fires. Last year I was in constant fire mode (a combination of wet wood, heating with water straight off of the top of the tank and a bit of an undersized boiler). This year I kind of miss that "excitement". I started a fire last night, was out all day at a business meeting and am here typing this post at 8:00 PM without having visited my basement yet - seems silly but I miss the pressure of starting fires, adding wood, etc..

 

[JohnDolz]

Welcome to WI. With the Very dry oak and locust, I'd certainly think about a lambda control. we have a number of effecta's running in Wi at this point, and they've been pretty good, once you get people up to speed on dry wood (you're the choir) the main issues have been keeping things clean (the 02 sensor and the fan area) and the cost.
We're dealing with Heatmaster G series boilers mostly at this point, with some GARN's thrown in. Heatmaster is willing to spec, build and ship buffer tanks for us if we need (409 stainless and really good pricing). We've put a handful of them in, and they certainly seem to be "set it and forget it" mostly because they are not lambda, but still have really good emissions and efficiency numbers, and a price that I can sell them at.

What part of the state are you headed for? we all know the boiler world is changing here in the US, so if it's a couple years out, don't plan too far out.

karl

Karl - Wondering if I can askk you what to keep an eye out for on the O2 sensor and fan? Last year I cleaned the fan 2 or 3 times, never touched the O2 sensor - didn't notice anything but I also didn;t know what I should be looking for.

As far as the dry wood goes, I could not agree more!

 

[__dan]

T Based on this I assume the turndown feature is used in conjunction with your injector pump to keep you storage/slab in the target zone, correct?

No, the boiler burner firing and the mixed, reset distribution HW temp are two completely different and independent variables. They have different requirements and are not tied to each other in any way.

Turn down of the burner (burning) firing rate happens when the HW supply temp exceeds the setpoint, currently 70 C on my boiler. The Froling has turn down ability with Belimo motorized operators on primary and secondary air dampers. Primary air will close down to 20% open from 100% and the draft fan slows from 80% to 30% (numbers from memory, in that range). Secondary air damper is controlled, varied, to achieve setpoint of 8% excess combustion O2 (the lambda sensor). The boiler has no knowledge of what is happening to the load, except that HW supply temp has met and exceeded setpoint.

The load controls are not what they will be in the future. Same for the tank. It is unfinished but works perfectly in the present state.

The load is a high mass all concrete radiant slabs with a slow response time , so OAT reset is essential for controlling the comfort level without overheating. Basement slab is slaved to the boiler circ to maintain constant load on the boiler, but the radiant temp is independently controlled by the Tekmar reset controller(s). One hour from firing on a cold start, off overnight, the slabs are returning 110 F and all the boiler sees is that HW supply temp has exceeded setpoint and it turns down the firing rate, reducing primary air and slowing the fan speed. The boiler spends 90% of its time at low fire, but constant burn with constant flow and load.

As is, I have to be careful to not overfire the boiler by not overfueling, so operator error can certainly cause slumbering, which I have very little trouble with myself. When it does slumber under the present system it's at the end of the burn so on charcoal and not with new fuel where it would be offgassing lots of H2O and tar / creosote. The only thing I have to clean out anywhere is very fine light white non combustible ash.

The tank would reduce the care needed to avoid slumbering from overfueling and give more convenience to DHW making, as intended. The tank is necessary, I would never say otherwise, but so is the insulated concrete foundation for the thermal flywheel and OAT reset of the distribution HW temp. That I would say is my idea of a reference design.

Edit to add that the Froling is a very well engineered and validated product. At low fire under constant low load the HW supply temp keeps going up slowly, commonly 70 80 90 C. At 93 C the boiler will go into slumbering and stop the fan, but it will keep slowly drafting. That fact that it works so well in auto is not just the controls but the mechanical / combustion engineering of the product, which is superb and well worth the money. Great product.

 

[JohnDolz]

No, the boiler burner firing and the mixed, reset distribution HW temp are two completely different and independent variables. They have different requirements and are not tied to each other in any way.

Turn down of the burner (burning) firing rate happens when the HW supply temp exceeds the setpoint, currently 70 C on my boiler. The Froling has turn down ability with Belimo motorized operators on primary and secondary air dampers. Primary air will close down to 20% open from 100% and the draft fan slows from 80% to 30% (numbers from memory, in that range). Secondary air damper is controlled, varied, to achieve setpoint of 8% excess combustion O2 (the lambda sensor). The boiler has no knowledge of what is happening to the load, except that HW supply temp has met and exceeded setpoint.

The load controls are not what they will be in the future. Same for the tank. It is unfinished but works perfectly in the present state.

The load is a high mass all concrete radiant slabs with a slow response time , so OAT reset is essential for controlling the comfort level without overheating. Basement slab is slaved to the boiler circ to maintain constant load on the boiler, but the radiant temp is independently controlled by the Tekmar reset controller(s). One hour from firing on a cold start, off overnight, the slabs are returning 110 F and all the boiler sees is that HW supply temp has exceeded setpoint and it turns down the firing rate, reducing primary air and slowing the fan speed. The boiler spends 90% of its time at low fire, but constant burn with constant flow and load.

As is, I have to be careful to not overfire the boiler by not overfueling, so operator error can certainly cause slumbering, which I have very little trouble with myself. When it does slumber under the present system it's at the end of the burn so on charcoal and not with new fuel where it would be offgassing lots of H2O and tar / creosote. The only thing I have to clean out anywhere is very fine light white non combustible ash.

The tank would reduce the care needed to avoid slumbering from overfueling and give more convenience to DHW making, as intended. The tank is necessary, I would never say otherwise, but so is the insulated concrete foundation for the thermal flywheel and OAT reset of the distribution HW temp. That I would say is my idea of a reference design.

Thanks for the continuing education and I understand where you are looking to go and it sounds great. Since you have no storage currently I am thinking the injector pump controls the amount of hot water being pulled away and sent your slab (target is set by your OAT), as your slab approaches target temp the injector uses less and less hot water which then causes your boiler to reach its set point, turndown kicks in until the slab cools or demand increases and the cycle starts again. Am I getting closer?

Since you are spending 90% at low fire I would bet that you are going to see efficiency gain when you have the tank in place but again 3 cord is awesome!

 

[__dan]

That's it, now you have it. Except that I do have storage. The slab is a huge load and will suck down the oil. Instead of oil, I charge the slab with yard debris.

Once the slab is up to temp, the maintenance load is a lot less. It really takes to January from October before the heat has really penetrated and spread out fully to the entire mass of the house. That's when, if the outside air temp goes up to 40 F from 20, the house will go from 68 to 72 even with the boiler off for a day or two. I certainly have storage. Looking at 31 outside 73 inside right now.

 

[JohnDolz]

Thanks. I should have been specific in saying tank storage which has the ability to store 200 +/- water. On one of the threads NP Alaska posted an article about a house in Alaska that heats 100% off of solar. It has a giant concrete slab and a 5000 gallon storage tank. If I remember correctly they can get through 2 or 3 months without sun just with the heat in the slab and in the tank. Cool (or should I say warm) stuff. Thanks again.

 

[Karl_northwind]

Karl - Wondering if I can askk you what to keep an eye out for on the O2 sensor and fan? Last year I cleaned the fan 2 or 3 times, never touched the O2 sensor - didn't notice anything but I also didn;t know what I should be looking for.

As far as the dry wood goes, I could not agree more!

just pull and clean off the 02 sensor once or twice a year, and pull the fan and clean out that area once a year and you'll be fine. no more work than any other boiler really, just gotta remember to do it.

k

 

[JohnDolz]

just pull and clean off the 02 sensor once or twice a year, and pull the fan and clean out that area once a year and you'll be fine. no more work than any other boiler really, just gotta remember to do it.

k

Great, thanks. Just wanted to be sure I wasn't missing anything.

 

[maple1]

That's it, now you have it. Except that I do have storage. The slab is a huge load and will suck down the oil. Instead of oil, I charge the slab with yard debris.

Once the slab is up to temp, the maintenance load is a lot less. It really takes to January from October before the heat has really penetrated and spread out fully to the entire mass of the house. That's when, if the outside air temp goes up to 40 F from 20, the house will go from 68 to 72 even with the boiler off for a day or two. I certainly have storage. Looking at 31 outside 73 inside right now.

What does your typical day to day burning schedule look like?

 

[Eric Johnson]

Thanks, everyone. I'm relocating from Central NYS to central Wisconsin in the spring of 2018 to manage the family tree farm in Coloma. We have 280 acres of planted pine and natural oak stands, a sawmill, forwarder--all that good stuff. My late dad put in a Heatmor OWB that lasted maybe 20 years before it gave out. Mom and I replaced it with another OWB, but I can't bring myself to use it. So, I'm going to do it right with a gasifiier. I need to heat 1,800 square feet of old farmhouse and a shop, so 60KW might be overkill, but with storage, that's less of an issue. I don't mind spending extra to get quality and good engineering. Pays off over time. But, as someone said, a lot change change in the market in 2 years, so we'll see what it looks like in a couple years.

 

[JohnDolz]

Thanks, everyone. I'm relocating from Central NYS to central Wisconsin in the spring of 2018 to manage the family tree farm in Coloma. We have 280 acres of planted pine and natural oak stands, a sawmill, forwarder--all that good stuff. My late dad put in a Heatmor OWB that lasted maybe 20 years before it gave out. Mom and I replaced it with another OWB, but I can't bring myself to use it. So, I'm going to do it right with a gasifiier. I need to heat 1,800 square feet of old farmhouse and a shop, so 60KW might be overkill, but with storage, that's less of an issue. I don't mind spending extra to get quality and good engineering. Pays off over time. But, as someone said, a lot change change in the market in 2 years, so we'll see what it looks like in a couple years.

Sounds exciting, best of luck! Based on what I know a 25kw or 35 kw with 400/500 gallons of storage will most likely meet your needs (depending on the size of the shop). That being said I always try to plan on things that I will grow into vs. grow out of so give the future some thought as well.