# DIY Lambda



## PlayWithFire (Jan 13, 2014)

I have been doing a LOT of research on inside wood boilers which I plan to install in my basement.  The boilers with the Lambda controls are really appealing to me.  It seems like they would be able to control the burn so much better without needing me to fiddle with the setting.  The down side, is the boilers with this option seem to be close to twice the price of a boiler without.

    This got me thinking, has anyone ever tried to retrofit a Lambda style controller (plus the hardware) to a boiler not originally made for it? Was it cost effective?

    Any opinions on how much of a difference the Lambda controller makes?

    How often do non-Lambda boilers need adjustment?  Seems like it might be frequent judging by the tuning threads for BIOMASS and EKO.
Thanks!


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## henfruit (Jan 13, 2014)

The lambda controlled boilers are not twice the cost of a boiler with out lambda. I have seen some boilers without lambda cost more than the ones with it.You will get better efficiency with lambda.


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## NE WOOD BURNER (Jan 13, 2014)

FYI


http://60degreev6.com/forum/showthread.php/42939-Making-a-Lambda-controller

This was for an internal combustion engine where the fuel can be regulated but similar>


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## hiker88 (Jan 13, 2014)

I'll jump right in as a Lambda owner.  When you ask how much difference the Lambda controller makes, my guess is that this thread will turn into a big debate about the efficiency of Lambda vs. non Lambda boilers.  That discussion escalates as quickly as storage vs non storage.  

However, I can tell you as a Lambda owner, that efficiency was not my biggest reason for buying the unit.  I'll also say that the Lambda controller makes a huge difference to me.  This is because I really bought the unit for the convenience it offers,  and also because of my nature.  I'm the kind of person that would spent a lot of time fiddling with a traditional unit and making sure it is running just so.  The geek in me also enjoys seeing this unit do it's thing.  

My guess is that it wouldn't be cost effective to retro fit a non lambda unit.  If you want to do it as a proof of concept, or if you like to tinker that's another story.  I suppose if someone had access to all the parts and controls it could be different.

Here is where the Lambda controller really "makes a difference" for me.  Your mileage may vary as they say.

- ignition to gassification in less than 3 minutes with normal sized (4-6 inch) firewood and no kindling
- No concerns about how\when to open the primary combustion door
-No "bridging" of firewood
-no need for barometric damper and adjustment
-works well with unpressurized storage (I charge my unpressurized storage to 85c top, 80c bottom with a boiler set point of 88c). Now that I weigh my wood before burns, I do this with zero idling
-zero smoke issues - unit is smart enough to set fan to 100% when loading, thereby sucking any escaped smoke into the bypass
-Overall quality of the boiler and features (the lighting door, cast iron nozzles, turbolater cleaning system etc.).

Am I burning much less wood than someone with a comparable non-lambda boiler and storage- maybe, but I can't imagine it's a huge difference.


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## NE WOOD BURNER (Jan 13, 2014)

Henfruit: Do you know what type of Lambda sensor the Vigas is running? I guess this could be an open question for other makes as well.

In automotive applications they will last 100,000 miles before replacement is necessary.   I suppose one could compare based on BTU/heat output per mile of a car and apply to boiler btu output/hour.

Going by memory but unheated = less longevity of sensor  heated = longer life of sensor
contaminates such as silicone are sources of  failures in cars. high temp silicone for exhaust pipes are common. and many spray the firebox in the off season with petro products will these have an effect on the sensors?

FTR: Lambda is a great technology but I am only familiar with its background on the internal combustion engine and troubleshooting drivability problems on vehicles. I do not own or operate a lambda boiler questions are just open for knowledge gain.


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## PlayWithFire (Jan 13, 2014)

henfruit said:


> The lambda controlled boilers are not twice the cost of a boiler with out lambda.


Here was one example of 2x the price. http://www.smokelessheat.com/categories/gasification-boilers
I have been looking at a lot of options, so maybe I am not alway been comparing apples to apples.
henfruit, In which situations do you see Lambda realy shine?
-decrease startup time?
-changing wood types/moisture content?


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## PlayWithFire (Jan 13, 2014)

hiker88 said:


> convenience it offers, and also because of my nature. I'm the kind of person that would spent a lot of time fiddling with a traditional unit and making sure it is running just so. The geek in me also enjoys seeing this unit do it's thing.
> ...
> - ignition to gasification in less than 3 minutes with normal sized (4-6 inch) firewood and no kindling
> - No concerns about how\when to open the primary combustion door
> ...


You hit the nail on the head. When we’re talking efficiency’s in the realm of 90%, efficiency is no longer the biggest issue in my book. It seems like Lambda adds value via “ease of use”.
What I’m wondering is how much additional “Work” do the non-Lambda’s really need?  And is this occational work(once a month) , or every fire?


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## flyingcow (Jan 13, 2014)

I may be a bit lazy. But I haven't adjusted my Innova for a couple of yrs. But I only burn rock maple and beech. MC of wood will be %21/22 at the beginning and down to %18 later on. I should get back in the habit of fine tuning, but it seems like I'm chasing my tail at times.Also, my ease of start up I think is good. Throw in kindlin', paper on top and light. Then I go fill my wheelbarrow full of wood and fill the unit. That's it. Takes about 10 minutes total, because I usually split my kindlin' before I start the fire.

Also note, if i was to buy a new unit I'd look very seriously at a Froling'. The way that plays with storage is impressive. *Which it should be for the extra coin.* Just the fact that it adjusts fan speed as storage is getting to the top temps is pretty neat.

Please note, I am a truck driver not a heating guru. There are some knowledgeable people on this site. 

Good Luck.


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## henfruit (Jan 13, 2014)

Ease of use in starting a fire is not what lambda is all about. The sensor measures the exhaust gases and sends the info to the controller that then tells the servo motor which way to operate, depending on weather the boiler needs more primary or secondary air. Wood species and moisture content will play a part in what the sensor is telling the controller.


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## flyingcow (Jan 13, 2014)

I looked at a Vigas a couple of yrs ago at a show. Got to look up close.  Also Mark from AHONA had a unit on display, that he keeps in the back of a trailer. Nice demo unit. I thought it was a rugged well built unit. And those can have Lambda controls. Not sure the controls had the finesse of a Froling', but it seemed to work nice.


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## henfruit (Jan 13, 2014)

NE Wood ,The sensor is a heated wide band Bosch.
Cow, What do you mean by finesse?


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## NE WOOD BURNER (Jan 13, 2014)

The sensor itself adds some degree of cost depending on type. What the controller actually controls and how it is controlling it is another.Hence my open question.

I would buy a Lambda unit but for me(DIY) my OBDII scanner does not plug into the boilers-LOL

I am probably the same age as the original Lambda sensor developed by Bosch definitely older than the first one put in a US car.


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## NE WOOD BURNER (Jan 13, 2014)

thanks Henfruit

With that being said: the sky is the limit on what you want to control to add both environmentally safe features and features that are convenient as well.

From Wikipedia:
*Wideband zirconia sensor[edit]*
Main article: AFR sensor





A planar wideband zirconia sensor (schematic picture)
A variation on the zirconia sensor, called the "wideband" sensor, was introduced by NTK in 1992[3] and has been widely used for car engine management systems in order to meet the ever-increasing demands for better fuel economy, lower emissions and better engine performance at the same time.[4] It is based on a planar zirconia element, but also incorporates an electrochemical gas pump. An electronic circuit containing a feedback loop controls the gas pump current to keep the output of the electrochemical cell constant, so that the pump current directly indicates the oxygen content of the exhaust gas. This sensor eliminates the lean-rich cycling inherent in narrow-band sensors, allowing the control unit to adjust the fuel delivery and ignition timing of the engine much more rapidly. In the automotive industry this sensor is also called a _UEGO_ (for Universal Exhaust Gas Oxygen) sensor. UEGO sensors are also commonly used in aftermarket dyno tuning and high-performance driver air-fuel display equipment. The wideband zirconia sensor is used in stratified fuel injection systems, and can now also be used in diesel engines to satisfy the upcoming EURO and ULEV emission limits.

Wideband sensors have three elements:


Ion oxygen pump
Narrowband zirconia sensor
Heating element
The wiring diagram for the wideband sensor typically has six wires:


resistive heating element (two wires)
sensor
pump
calibration resistor
common


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## NE WOOD BURNER (Jan 13, 2014)

henfruit said:


> depending on weather the boiler needs more primary or secondary air



So is there some type of barometric sensor as well on these units? Or is the controller adjusting after the fact with readings from the oxygen content retrieved from the Lambda sensor?


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## kopeck (Jan 13, 2014)

flyingcow said:


> I may be a bit lazy. But I haven't adjusted my Innova for a couple of yrs. But I only burn rock maple and beech. MC of wood will be %21/22 at the beginning and down to %18 later on. I should get back in the habit of fine tuning, but it seems like I'm chasing my tail at times



You are not the only one.

The first two years I had mine I played with it a bit but found a was always more or less where a started out.  This year I just left it and have been happy with the results.

K


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## hiker88 (Jan 13, 2014)

henfruit said:


> Ease of use in starting a fire is not what lambda is all about. The sensor measures the exhaust gases and sends the info to the controller that then tells the servo motor which way to operate, depending on weather the boiler needs more primary or secondary air. Wood species and moisture content will play a part in what the sensor is telling the controller.



It's definitely part of what it's about though.  My unit will monitor flu gas temp, boiler temp and residual oxygen content to determine the optimal time to shut off the fan, circulator pump, and to close the air intakes so that I have an base for my next fire, that's how I can load the boiler with 100 pounds of normally sized firewood, light it with nothing but newspaper and I'm back upstairs about 3 minutes after putting a match to it.

If other members on this forum have boilers with gremlins that relight the fire for them, I have gremlins that put a couple inches of Kingsford briquettes in the firebox after each burn.


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## skfire (Jan 13, 2014)

hiker88 said:


> It's definitely part of what it's about though.  My unit will monitor flu gas temp, boiler temp and residual oxygen content to determine the optimal time to shut off the fan, circulator pump, and to close the air intakes so that I have an base for my next fire, that's how I can load the boiler with 100 pounds of normally sized firewood, light it with nothing but newspaper and I'm back upstairs about 3 minutes after putting a match to it.
> 
> If other members on this forum have boilers with gremlins that relight the fire for them, I have gremlins that put a couple inches of Kingsford briquettes in the firebox after each burn.


 
what he said...and the lighting door is a brilliant improvement....do they have it trademarked????
unless one experiences the easiness of operation and peace of mind, it is hard to convey.
SK


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## ewdudley (Jan 13, 2014)

hiker88 said:


> t's definitely part of what it's about though. My unit will monitor flu gas temp, boiler temp and residual oxygen content to determine the optimal time to shut off the fan, circulator pump, and to close the air intakes so that I have an base for my next fire, that's how I can load the boiler with 100 pounds of normally sized firewood, light it with nothing but newspaper and I'm back upstairs about 3 minutes after putting a match to it.


A conventional downdraft gasser doesn't need elaborate controls in order to have charcoal left to light the next fire.  And of course lighting is just as easy, just wave propane torch over charcoal for literally five seconds, pile on full size splits, and done.

I gather that there are some folks who like to mess with air mixture, but I haven't adjusted mine in four years and have enjoyed smokeless efficient operation the whole time.

And as someone who keeps 100% inventory of spare components, it's nice not tying up funds for spare LCD screen, lambda sensor, servo motors, micro-controller boards, and whatnot.


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## Vizsla (Jan 13, 2014)

Anyone have to replace their oxygen sensors yet?
I personally like the lambda most for the clean burn, which equals max efficiency of the burn part. We have built custom sensor controls for our 2-stroke drag racing and clean burning project snow machines. There was a lot to be had from that application, consistent power and control. However a very pricey application for just a little bit more power, the best part was having repeatable results in all conditions, summer thru winter. 

Its a good piece of mind knowing your getting the most out of your wood.........lol


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## skfire (Jan 13, 2014)

ewdudley said:


> A conventional downdraft gasser doesn't need elaborate controls in order to have charcoal left to light the next fire.  And of course lighting is just as easy, just wave propane torch over charcoal for literally five seconds, pile on full size splits, and done.
> 
> I gather that there are some folks who like to mess with air mixture, but I haven't adjusted mine in four years and have enjoyed smokeless efficient operation the whole time.
> 
> And as someone who keeps 100% inventory of spare components, it's nice not tying up funds for spare LCD screen, lambda sensor, servo motors, micro-controller boards, and whatnot.


 
So I should let the warden run the torch?????.....lol.....she has enough weapons. In all seriousness, it all is as you say in said case, but I like the option of the wife being able to run it and the lighting door for one makes it very simple.


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## huffdawg (Jan 14, 2014)

How does a Lambda sensor eliminate bridging? 
I have no concerns with the primary combustion door as I don't open it till the fire goes out.   
I haven't timed it  but I think I can get gasification in 3 mins. And I don't need news paper.    But thats not enough time for a cold beer.   Well  Almost ...
I also have most the capabilities that EW has .  

The warden knows how and she doesn't like any tips from me.


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## ewdudley (Jan 14, 2014)

Back to the OP subject, yes you can do a DIY lambda control.  It looks like it sure helps to know what you're doing:

https://www.hearth.com/talk/threads/not-your-grandpas-garn.80938/

Looks like Tom is just over the hill from your place, I've found him to be generous with his time, maybe he can offer some first hand insight.


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## hiker88 (Jan 14, 2014)

huffdawg said:


> How does a Lambda sensor eliminate bridging?



If the boiler is +- 2 c of set point, the fan will run at 85%.  I forget the exact specs on the fan, but I think it is close to 600 cfm.  Also, with chunky pieces of wood, I will see the residual oxygen content go up, which closes the secondary towards 10% and opens the primarys towards 99% - this is the setting you see when starting from a cold boiler.  So, the unit constantly adjusts and the result is no bridging.  I burn year round, and it doesn't matter what kind of wood I put in, I've never found anything but the usual coals and ash at the end of a burn.

Conversely, it's impressive to watch the unit when it is running too hot.  I haven't caught it this winter, but there was a very cold, windy (30-40 mph gusts) night when I went down to check the boiler.  I noticed it seemed to be running kind of quiet based on the fact that I had started a fire not too much earlier.  It was so windy that night, that the flu gasses were higher than usual, the fan had slowed down even though the boiler was below set point.  It will do this if flu gas temps get close to 250c as the gassification  process can be interrupted if flu gas temps get too high.


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## jebatty (Jan 14, 2014)

I have used a Froling FHG-L50 and a Tarm Solo Plus 40. And I can't answer the efficiency question, other than published info on the Froling and my measurements on the Tarm. And like others, I have set the primary/secondary air control on my Tarm once and left it alone since 2007.

Yet, the Froling or similar would be my choice when and if I ever have to replace the Solo Plus, and if $$$ was not a consideration. Ease of operation in every respect favors the Froling, from starting, to loading, to the way it burns to maintain constant output, to lack of smoke roll-out, to its really cool appearance, and a lot more. In either case, however, I think adequate storage is essential to assure maximum efficiency and ease of operation.


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## NE WOOD BURNER (Jan 14, 2014)

Vizsla said:


> the best part was having repeatable results in all conditions, summer thru winter.



I believe this is the biggest advantage to a Lambda boiler. this is environmentally sound.  It will no doubt be mandated in the near future. IMHO

I am reluctant to purchase a Lambda for parts availability reasons. When I purchase things I always look up price and availability of parts. Mechanical/electrical they all will fail at some point if I pay top $ I need to know I can get parts locally to fix it. Things only break when you use them. so if dealer don't stock them I need to.
I like some of the boiler internet sites, because you can look at boilers and look at parts availability and pricing in one storefront. Also lets you know what would be common for breakdown.

12valve cummins are selling for top dollar right now because they provide durability with out complicated controls.


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## chuck172 (Jan 14, 2014)

I like simple things. I don't even like cars with computers and sensors.


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## TCaldwell (Jan 14, 2014)

Lambda/o2 control in concept is easily understood, take a batch of wood and manipulate the premetered p/s airflows to maintain a preset o2/lambda value based on optimum combustion for a given boiler design. Basically you are retarding the initial combustion rate by reducing primary air and increasing the secondary. If you looked in the firebox of a lambda controlled boiler 15 minutes after starting the fire, you will see virtually no fire. There is just enough to offgas and reburn in the secondary. Without lambda control you will see more flame in the primary chamber and probably a lower o2% after the same 15 minutes. The premise is a controlled fire is more efficient than one that isn't, less puffing and lower overall flue temps and more consistent burns with varied wood to name a few. A non lambda boiler with the correct air settings for a given moisture content wood with a knowledgeable operator can do just as well, just not as consistent. For alot of folks a burn is good if your only criteria is hot water and no smoke, possibly you might think differently if you felt the need to monitor the combustion process. The predominant sensor used is a bosch 4 wire lsm11 wideband. The sensor gives the controller current feedback to create a output to the dampers. Largely the controller is based upon a propriertary pid algorithim with discrete inputs like temp to trigger alarms that might reduce fan speed when approaching high water temp, or set specific damper positions at start and end of burn. I would be glad to help anybody with diy lambda, it takes alot of time patience and money, the real cost savings would be to buy a proven lambda equipted boiler from the start!!


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