# Lambda controls vs baseline; fault-mode fallback, etc.



## pybyr (Mar 12, 2011)

I was thinking about some of the recent other discussions about boilers with lambda controls for blower speed and/ or air inlet settings for primary and secondary combustion chambers-

I fully accept the theory and practice that such controls can lead to improved efficiency-- as they can probably allow only slight proportions of necessary "excess air" at each and every stage of a burn, and with variations in wood- when compared to a 'standard'  gasifier [which needs to always supply enough air for any possible set of variables- which will mean too much air under some substantial range of actual conditions]

But it's hard to do an apples-to-apples due to the fact that other models without lambda controls have other variations in design, and that each system/ heat load has its own variations.

With automobiles (that also use oxygen sensors in the exhaust for the same purpose, there's a "limp home" mode so that the vehicle can still be operated if the O2 sensor fails.  You don't want to run in that mode for an extended period, but the system allows function pending repair.

Does anyone know if the Froling, Effecta, etc., have a "limp" mode to operate if the 02 sensor fails, and if so, whether there is any likely harm done if someone were to do a few short test burns with the 02 sensor removed or disconnected [one might want to temporarily remove the sensor and put in a plug, so that the sensor does not get contaminated by higher levels of combustion byproducts that may occur when not running in "closed loop" lambda control).

A "smart boiler" in "limp" mode would presumably operate in a comparable way to a "dumb" gasifier- with operating settings allowing adequate excess air under all expected stages of combustion and likely wood types/ conditions- only all of the other boiler and system variables would remain the same.

If that were possible, someone with instrumentation might be able to take measurements [using weighed amounts of wood from the "same batch"] to see just how significant a performance advantage results from lambda control.

It'd be very interesting to find out just what magnitude of efficiency gain one gets from the added expense and complexity of the more advanced control system.

Also, as I began to think about this, it also occurred to me that this ability to have a "failsafe" mode could be a relevant factor for owners (or potential buyers) in light of the fact that the 02 sensor is quite likely a specialized and somewhat expensive part that might need to be ordered/ waited for.


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## TCaldwell (Mar 12, 2011)

I suspect most manufacturers have thought this out in their control stratedgy, for some sort of overide. in 2 years with the same bosch lsm 11 industrial sensor it has not failed, but i do have a backup spare. when the power goes out, one damper closes and one stays open, not a problem for a garn type boiler. I am not sure if a failed o2 goes high, low but i think i will look into it.


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## Willman (Mar 12, 2011)

> 02 sensor is quite likely a specialized and somewhat expensive part that might need to be ordered/ waited for.



To check on automotive parts reliability I just ask the dealers parts dept. for the sales history of any part in question. The amount of parts sold that are similar across a number of platforms can give a fairly good idea as to the quality factor.

Good question on the fail safe mode. It would be nice if they could run in "dumb mode" Although with the manufacturers being Euro I imagine that the o2 sensors are a cut above the auto variety. Anybody know how much a sensor cost on any lambda unit?

I think that the technology behind the o2 setups are also meant to keep everything proprietary to each boiler or else second tier manufacturers would be lifting them for their own use.
On that note when are the Chinese gonna clone any modern wood burning technology ? Prolly not enough of a market just yet.

As one who is planning on a purchase in the coming year or so I would like to know as much as I can before pulling the trigger as I only have one round in the chamber so to speak.

Will


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## pwschiller (Mar 12, 2011)

How would the boiler even know that the sensor was even failing, unless it was a nearly complete failure? In other words, how would the boiler know if the sensor was dirty or was starting to fail? Maybe as the operator you have to pay some attention to the combustion chamber temps and flue gas temps to make sure that they aren't far off what they've historically been.

I understand your skepticism regarding the lambda sensors. I plan on getting a boiler with a lambda sensor though. I know that there are plenty of people out there getting reasonably efficient burn cycles with non-lambda boilers, but I've also read enough comments from people who have been frustrated trying to get their primary and secondary air intakes set properly on non-lambda boilers. Maybe their problem was that they were burning wet wood. I just know that if I spend $10K+ on a system that I want it to be simple to use. If I can save the cost or labor involved in cutting, splitting, and stacking an extra cord of wood each year that a less efficient boiler would use, then I think I'll be happy with my choice. I guess time will tell.

It would be interesting if you could run some efficiency tests in both lambda-control mode and also in a manual mode with fixed primary and secondary air intakes over the course of several burn cycles to find out the relative efficiencies with the exact same boiler. 

BTW, the Effecta is also available in a non-lambda version and I believe the that the Froling FHG-S is the non-lambda version of their boiler.


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## Willman (Mar 12, 2011)

> BTW, the Effecta is also available in a non-lambda version and I believe the that the Froling FHG-S is the non-lambda version of their boiler.



I wonder how the wood consumption differs on the non lambda boilers. If it was a cord a year it would definitely be worth the extra on top of the cleaner set it and forget it burn.
 Any test results out there on btu's released per 100 lb of wood burnt that anyone knows of?

Will


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## ewdudley (Mar 12, 2011)

Pete Schiller said:
			
		

> How would the boiler even know that the sensor was even failing, unless it was a nearly complete failure? In other words, how would the boiler know if the sensor was dirty or was starting to fail? Maybe as the operator you have to pay some attention to the combustion chamber temps and flue gas temps to make sure that they aren't far off what they've historically been.



As my dad used to say, "And then the fun began.".

Self-diagnostics, sensor redundancy, alarm modes, prognostics, limp-modes, fail-safes, failure mode effects analysis, telemetry, performance monitoring, data recording, self-optimization, model-constrained control loops, operator displays, DDC system integration.  Not your daddy's boiler, not anymore. All proprietary. All fun.


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## pwschiller (Mar 12, 2011)

ewdudley said:
			
		

> Not your daddy's boiler, not anymore.


I'm surprised that you got yourself one of them newfangled wood boilers, what with all of the pump and fan motors that could break down. I mean, you could have had yourself a real simple pre-catalytic converter wood stove.

I appreciate your concern that adopting relatively new technology may not always be problem free. If your concern is that we will be temporarily left without heat should our lambda sensors fail, in my particular case I will have my existing oil boiler as a backup. If your concern is that our boilers won't be good for anything except boat anchors should our sensors or electronic components fail, if I purchase a boiler from a company with a proven track record that is designing best in class products, it is much more likely that they will still be around in years to come should I need replacement parts. Worst case, the stepper motors can be disconnected and the fan and loading pump can be run independently from the boiler electronics. Whatever boiler I choose, my system will have a pressure relief valve, a UPS backup for the loading pump, a high limit aquastat to turn off the fan (as a backup if the boiler controls fail to turn off the fan and shut the air intakes), and gravity feed if the UPS or loading unit fails as well.

I'm viewing my purchase of a wood boiler as a long-term investment that I hope will last for 20+ years. Buying one with a lambda sensor adds less than 10% to the total system cost, but will probably save me upwards of a cord of wood per year. It doesn't make sense for me to hold off on purchasing a wood boiler just so I can see how reliable the lambda sensors are, and I don't want to forego the benefits it provides for the next 20 years. If you have had a negative experience with a particular brand in the past, then by all means, let it be known so that others can benefit from your experience. But I don't think that you should be discouraging others from purchasing products that offer technological improvements by trying to relate them to old fuel injection technology. If you're happy with the boiler that you've chosen, and there isn't a thick cloud of smoke coming out of it and floating in the direction of my house, then you made a good choice and I'm happy for you.


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## Nofossil (Mar 12, 2011)

I bought a lambda sensor to add to my EKO. Haven't had time to install it yet :-(

One concern I have is sensor life. Lambda sensors are supposedly very sensitive to some types of contaminants, and I assumed that at the very least I'd need to protect it from gunk that's present in the flue gas during startup.

My strategy is to use the lambda sensor to determine the 'ideal profile' for primary / secondary air flow rates over the course of several burns, then remove the sensor. 

From that point on, use time and combustion temperature to estimate where the boiler is in the burn cycle, and use the relevant 'ideal profile' settings. 

I wouldn't be surprised if I weren't the first person to think of that approach, even though it's more sophisticated than what our cars do when they have no functioning lambda sensor. Of course, whatever solution they have is doubtless proprietary.


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## NYEDGE (Mar 12, 2011)

nofossil said:
			
		

> I bought a lambda sensor to add to my EKO. Haven't had time to install it yet :-(
> 
> One concern I have is sensor life. Lambda sensors are supposedly very sensitive to some types of contaminants, and I assumed that at the very least I'd need to protect it from gunk that's present in the flue gas during startup.
> 
> ...



So, if I understand your strategy correctly, you would average out your findings with a lambda sensor to dial-in a "sweet spot" that would give you the best overall performance through the burn?
I adjust my secondary air after the unit is burning at least an hour so that it is up to temperature, has a nice bed of coals, and is gasifying strong.
If I adjust the intake so that I see a nice blue flame during that period, the unit should be working at a high point of efficiency during that period of the burn, for any given burn.
At the beginning and end of a burn, I would think that the unit is not running as efficient due to the lower temps, and lack of coals.
What I am doing is trying to get the most efficiency out of the unit during the period of time of the burn cycle that the most energy is available from the wood.
Is that your strategy with the lambda? To dial-in your unit?

BTW, your contributions to this site, and assistance to others is greatly appreciated.


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## shortline (Mar 12, 2011)

nofossil said:
			
		

> I bought a lambda sensor to add to my EKO. Haven't had time to install it yet :-(
> 
> One concern I have is sensor life. Lambda sensors are supposedly very sensitive to some types of contaminants, and I assumed that at the very least I'd need to protect it from gunk that's present in the flue gas during startup.
> 
> ...


 :cheese: 

nofossil, I am so glad to find that you have been working on this air flow rate control stuff.  I just posted that I needed to contact you about this very subject.  Have you seen my "didn't sleep well ... " post?  What do you think?  Am I spinning my wheels?  I own everything but the air induction, catalytic converter and controller of course.


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## TCaldwell (Mar 12, 2011)

The bosch industrial sensor is under $200.00, all o2 sensors are not the same, wide band , narrow band, 4 wire, 5 wire. If you wanted to use a specific sensor would need to research its compatibility with fluegas and temp requirements, as well a controller for the lambda or percentage range.my research found most automotive sensors although relatively inexpensive wont hold up in the wood enviornment for extended periods.


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## ewdudley (Mar 12, 2011)

NYEDGE said:
			
		

> I adjust my secondary air after the unit is burning at least an hour so that it is up to temperature, has a nice bed of coals, and is gasifying strong.
> 
> If I adjust the intake so that I see a nice blue flame during that period, the unit should be working at a high point of efficiency during that period of the burn, for any given burn.
> 
> ...



I've been running closed-loop flue gas temperature control for a month now, which makes it a lot easier to optimize primary and secondary air settings for a steady-state.

But a benefit I wasn't expecting is effect of being able to set an end-of-burn flue-temperature setpoint.  The draft controller shuts the fan off and closes the air inlet tight when flue temperature drops below the end-of-burn setpoint, which I currently have set to 290 degF.  

When the end-of-burn setpoint is set high enough there is still a full bed of coals, which turns into a bed of lump charcoal as soon as there's no more air.  The nice part is that when it's time to light a new fire the charcoal gets very hot very fast and the new fuel burns blue from the get-go.

https://www.hearth.com/econtent/index.php/forums/viewthread/69395/P45/

Cheers   --ewd


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## ewdudley (Mar 12, 2011)

Pete Schiller said:
			
		

> ewdudley said:
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You have no idea.  

We've gots pumps and ECM pumps, aquastats and differential aquastats, mechanical controllers and electronic PID controllers, and motors and relays Ã  gogo.  And they can all fail.  But there's spares for everything, and they're all reliable, affordable, commodity components that can be simply diagnosed as component entities without being at the mercy of Daryl and Daryl scratching their heads and swapping out sensors and control boards on my dime.

And the thirty year old VC wood stove with secondary combustion still sits in the family room, and it still burns hot and clean whenever we have occasion to fire it up, thank you very much.



> I'm viewing my purchase of a wood boiler as a long-term investment that I hope will last for 20+ years. Buying one with a lambda sensor adds less than 10% to the total system cost, but will probably save me upwards of a cord of wood per year. It doesn't make sense for me to hold off on purchasing a wood boiler just so I can see how reliable the lambda sensors are, and I don't want to forego the benefits it provides for the next 20 years. .



As you please.  

But the fact remains that a few years back I bought two Ford Focuses for the price of one Prius, and more recently I bought a nice efficient downdraft non-lambda boiler and a new rice-coal boiler for the price of one state-of-the art wood boiler.  

The Focuses burn precious little gas and I wouldn't notice a ten percent improvement in wood boiler efficiency, even if it were true.

--ewd


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## NYEDGE (Mar 12, 2011)

ewdudley said:
			
		

> NYEDGE said:
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I did follow your recent thread and I applaud you on your gumption, and advances.
While my unit does not do what you have been able to do with your mods, I am able to set up the boiler control module to shut down the fans at a preset flue temperature.
When the unit's flue temperature drops to 80C (176F), the unit shuts down the blower ends the cycle. I can change that end temperature, but I have found that around that temperature I am not creating anymore useful heat for the water, and it leaves me with a nice bed of black coal for the next firing.


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## ewdudley (Mar 12, 2011)

nofossil said:
			
		

> I bought a lambda sensor to add to my EKO. Haven't had time to install it yet :-(
> 
> One concern I have is sensor life. Lambda sensors are supposedly very sensitive to some types of contaminants, and I assumed that at the very least I'd need to protect it from gunk that's present in the flue gas during startup.
> 
> ...



This can work nicely.  

We used stepper motor controlled needle valves to control superheat on marine containerized refrigeration units, which relied on pressure sensor accuracy on the order of 15 millibars to perform well and not destroy the compressor.  But the pressure sensors weren't as reliable as we would have liked, especially in the middle of the ocean with, for instance, a million and half dollars or more worth of pharmaceuticals at stake, per container.

With a little data mining and elementary statistics I was able establish what the probability was that the pressure sensor was performing correctly by modeling stepper motor position as a function of ambient temperature and controlled space temperature.  The control range of the valve was constrained inside a probability range, and if it rode along the rails of the range for too long the pressure sensor input was abandoned and the stepper motor was controlled by the temperature model.   

It turned out the pressure sensor was only necessary for optimal performance, and the unit could work quite well without it, until it could be replaced at the next scheduled preventive maintenance. 

So yeah, I would say using the unreliable sensor to develop a model that can operate according to more reliable sensors is a good way to go. Just don't try to market it until you're sure you're not running afoul of the relevant patents.

--ewd


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## shortline (Mar 15, 2011)

Great thread -- hate to see it die.  Nofossill what do you think of Bosch's 411 5 wire Wide band Oxygen sensor? At first glance it look's worth a try to me (Although I've yet to see a price).  Who's sensor have you chosen to try?

I like the fact that it is self heating.  I think if we could figure a way to sample the flue gasses only when a drop in flue temperature is detected. The 5 wire being preheated could quickly determine if the drop in temperature is due to air/fuel ratio being too rich or to lean and make appropriate adjustments to the air induction.  Need to figure a clever way to get the flue gasses to pass over the sensor only when the control wants to determine the reason for a drop in temperature, this should prolong the life of the sensor.

I have absolutely no knowledge of how the Europeans are setting up their solid fuel lambda controls, but it seems to me that it would valuable for the controller to know approximately how much fuel is available for each burn.  To know if the temperature readings and lambda sensor readings are behaving in reasonable manner given the fuel available to system.  Do you think a set of load cells under my boiler is taking this all a little to far? :lol:


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## Nofossil (Mar 15, 2011)

That's funny - I'll swear I posted to this thread yesterday with some clarification. If so, the post evaporated....

I currently apply different control strategies based on where I am in the life of the fire - during startup I circulate water from storage through the zones and boiler to help get the boiler water jacket up to temp quickly (the ONLY time I have two circulators running). During ramp-up, I minimize heat loads and keep the recirc valve open to get the boiler outlet temp up as quickly as possible. During normal burn I modulate loads and boiler circ speed to maintain desired outlet temp. During burn-out I cycle the boiler circ as necessary to scavenge any remaining heat down to the lowest possible outlet temp.

My thought is that during each of these phases, there's a different ideal ratio of primary/secondary air. If I can get a better sense of what those ideal ratios are by using a lambda sensor, then I can apply those ratios even without having the lambda sensor connected.

I don't know the brand of my lambda sensor. It's a five wire self-heated wideband sensor that came with an amplifier / signal conditioner as a tuning kit for automotive use.


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## EffectaBoilerUser (USA) (Mar 15, 2011)

To answer the question regarding "limp" mode if the sensor on my effecta lambda 35 boiler fails, YES it does have a feature for this.

By hitting buttons A & B at the same time for 5 seconds puts the boiler in emergency mode and runs the boiler throughout the entire burn cycle at 70% secondary open and 30% primary open.

I am currently helping another effecta lambda 35 customer (who has a 5,000 sq. ft. house with a bunch of windows and 1,000 gallons of storage) data log a few burns in his boiler and once this is completed we will data log the effecta lambda boilers in this limp mode, thus getting a true, accurate comparison between lambda mode and no-lambda mode.

Regarding life of the lambda sensor, the engineering people at effecta have told me that they have had this lambda technology out for many years and have a very, very small failure rate. They use a very robust, high tolerance lambda sensor in the 35 and 60 kw effecta lambda boilers. They do recommend cleaning this sensor on an annual basis.

Knowing that effecta has been making gasifiaction boilers since 1983 and has a 40% market share of wood and pellet boilers in Sweden AND is now exporting to 10 different countries (up until 5 years ago they only sold their products in Sweden) tells me that they are a very outstanding company.

When I visited their facility last summer in Kungsbacka Sweden I was very impressed with the team of people they have there. It turns out the the owners of the company come to work everyday and play a very active role in the day-to-day business transactions. The owners of the company are the President, Quality Control Manager, Engineering Manager and Sales Manager.

I plan to be posting the lambda vs. non-lambda performance of the effecta lambda 35 boilers within a week or so so keep looking.

EBU


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## Nofossil (Mar 15, 2011)

Effecta Boiler User said:
			
		

> I plan to be posting the lambda vs. non-lambda performance of the effecta lambda 35 boilers within a week or so so keep looking.
> 
> EBU



Excellent!


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## shortline (Mar 15, 2011)

Effecta Boiler User said:
			
		

> Regarding life of the lambda sensor, the engineering people at effecta have told me that they have had this lambda technology out for many years and have a very, very small failure rate. They use a very robust, high tolerance lambda sensor in the 35 and 60 kw effecta lambda boilers. They do recommend cleaning this sensor on an annual basis.
> 
> EBU



Can you sell these sensors to non Effecta Boiler owners?  If so, I'd be interested in purchasing one.  Do have any specs. on them?


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## dogwood (Mar 15, 2011)

I think there is a Lambda version of the Tarm (Baxi) Solo Innova sold in Europe so I would guess I could do a retrofit on mine.  Anyone have an idea what Lambda sensor they use, or would be comparable.  What do you have to do to put in a Lambda sensor. Is it complicated? Hansson, a while back, mentioned the Lambda Solo Innovas were prohibitive in cost, but it doesn't sound that expensive to retrofit from what you are saying above. 

Mike


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## NYEDGE (Mar 16, 2011)

Seems that some might think that adding an off the shelf lambda sensor is as easy as buying one, and just plugging it in somewhere.
In addition to mounting the sensor, it would have to be hard wired to a control board that would take the information the sensor was reading,
analyze it in some sort of algorithmic form, and then control the secondary air with some sort of mechanical actuator/device.
I for one am not smart enough to figure that all out, so it looks to be a little more complicated than just buying a sensor.
Right?


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## Piker (Mar 16, 2011)

nofossil said:
			
		

> Effecta Boiler User said:
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Really looking forward to this... Since I don't have a data logger of my own, the only data I have been able to glean is based on the performance of two very different boilers, the Econoburn and the Froling... and lets face it, there's a lot more differences between those two units than a lambda sensor.  I suspect there's going to be a pretty decent margin between the two measurements on the Effecta.   I don't doubt that the combustion efficiency of a gasser with static primary and secondary air settings can reach extremely high levels, but I don't believe the average combustion efficiency of the unit over the course of an entire burn will be quite as high as a boiler with lambda technology.

Mr. Dudely,  as far as your take on the initial costs, reliability, and justification of more expensive and more complex lambda controlled units... I will concede to the notion that this perhaps should be a consideration for the homeowner, however, I don't think it's fair to say that simplicity of and by itself is the holy grail.  Try having a score of wood gassers in the field with cheap "simple" controls that don't work worth a hoot.  Talk about a boat anchor...  I'll take a score of expensive and complicated controls that work well over a mess of cheap ill-perfoming controls any day.  I'll also take a 0% vessel failure rate over a 15%... just sayin... 

The other thing I want to mention is that the cost of the lambda portion of the control really isn't all that much... you're only talking about $700 hundred bucks between an FHG-S and and FHG-L.  This covers the cost of the probe as well as the DC servos that control the dampers.  I think most of the cost of the more expensive "high end" units comes from manufacturing quality differences(both structural integrity and fit/finish), and of course differences in distribution.  Products that are backed by a large network of trained dealers are obviously going to cost more than products that are sold direct to the consumer over the internet from a single distributor... there's just more people involved in the process, ie the middleman.  The thing to remember is that a lot of people are more than willing to pay extra for a competent middle man who can back up their investment with local support.  For those who are comfortable with braving the waters of wood gasification on their own, there's plenty of cheap product out there for them to choose from... something for everyone.  

Lets not leave out the emissions factor... part of the move toward more sophisticated control technology is to be able to meet future emissions standards.  Love or hate the EPA, tighter restrictions are coming and the only way to deal with them is through development of new methods for hotter, more efficient combustion with greater reduction in particulate emissions.  Lambda controls are at least part of the answer.

As far as the reliability of the O2 sensors... so far I have not had any "issues."  The probe has a shroud around it that helps protect it from debris, and since the controls allow for a generous bed of charcoal to be made available at the beginning of every burn, it's only a couple minutes on start up that the probe even sees any smoke. Nothing EVER accumulates in the hx or draft inducer except very fine fly ash. One thing I have found is that over time, fly-ash will skew the O2 reading a bit... but only to a point... and as long as you know the baseline, you can adjust parameters to compensate as the sensor becomes "seasoned."  

I for one am all for moving ahead with newer and cleaner technologies in wood and biomass heating solutions... It's called progress and it's not a bad thing as Mr Dudely seems to imply with his satire, sarcasm and cynicism.  I am not naive enough, however, to think that everyone can be on the cutting edge of technology all the time.  It's an expensive place to be, though I firmly believe that you get what you pay for... at least most of the time - it's called the free market system, and it does usually work over time. You can look at just about any of our recent technology and point to naysayers that were dead set against it when it came out... from 8 tracks, to Cd's, from CRT televisions to plasma flat screens, from video cassettes to Blu-Ray disks... and perhaps someday from ford focuses to priuseeeeeees.  The cool think about Europe having a head start with this type of stuff is that by the time it gets over here, it's pretty well tested and most of the bugs have been worked out.  People adapt to progress for different reasons... some for a cause, some for financial gain, but most adapt because it improves their lifestyle.  While the FHG-L I am using probably saves me somewhere between 10% and 20% in firewood over the previous unit I owned, the best thing about it is the lifestyle it offers. 

cheers


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## shortline (Mar 17, 2011)

> For those who are comfortable with braving the waters of wood gasification on their own, thereâ€™s plenty of cheap product out there for them to choose fromâ€¦ something for everyone.
> 
> Lets not leave out the emissions factorâ€¦ part of the move toward more sophisticated control technology is to be able to meet future emissions standards.  Love or hate the EPA, tighter restrictions are coming and the only way to deal with them is through development of new methods for hotter, more efficient combustion with greater reduction in particulate emissions.  Lambda controls are at least part of the answer.
> 
> ...



Well said!


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## EffectaBoilerUser (USA) (Mar 18, 2011)

In response to a recent prior posting,

Yes, as the US distributor for effecta lambda boilers, I am able to sell all the components for a complete effecta lambda control system. The cost for the lambda sensor, lambda motherboard/control panel, 12V dc transformer and (2) 12Vdc stepper motors (one for primary and one for secondary) is approx. $595.00.

Please email me at brian@upnorthenergy.com and I can get your a fomal quote or answer additional quesitons.

By the way, the lambda sensor on the effecta lambda 35 and 60 kw boilers is a very robust, self heating sensor.

EBU


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## TCaldwell (Mar 19, 2011)

Brian, i see this unit has a o2 sensor but displays a co2 value, what is the reason for this. I am to assume this is  a calculated value based on the fuel factor and a given moisture content. The stiometeric residual o2 in the fluestream is approx 7% and a corresponding co2 of 13.25% for 20% mc.  According to the video it shows a approx setpoint of 7%o2. On a typical start of burn, how high of a co2 reading do you see, and how long does it take to get back to setpoint, does this differ with different types of wood. What sort of damper outputs in percentage do you see for the initial stage of burn. once the burn has stabilized with no appearant disturbances, does the process value oscilate or stray from setpoint. Is the draft inducer a single speed or does it modulate. if it modulates is that controlled by flue temp. what is the control signal to the stepper motors, voltage or current. What sort of parameter indicators or alarms are offered with the controller and what parameters can you manipulate. These are questions as to the viability or flexibility for use on other boilers. i called early this morning, left a  message hoping to talk to you, figured you must be busy, but since you offered on a prior post, these questions maybe could be answered once here than to each email.
  thanks  tom


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## EffectaBoilerUser (USA) (Mar 21, 2011)

Tom,

The effecta lambda boilers use a CO2 sensor which is located in the base of the chimney. This sensor monitors the CO2% of the smoke leaving the boiler and with the help of the motherboard, opens and closes the primary and secondary drafts using the stepper motors. The motors move in 10 degree increments and always move as a pair, in opposite directions. Thus, if the CO% gets higher than the preset setting (usually 13%) the primary draft will close 10% and the secondary draft will open 10%. If it still continues to rise they will keep closing/opening until 13% is reached. 13% is the normal setting for 20% MC wood. However, if the wood is a little less seasoned it can be set to a higher value which results in more air being added to the primary chamber and less to the secondary chamber. If it is a little dryer, the opposite is true.

The effecta boiler uses a fixed speed fan located at the rear of the boiler, thus resulting in a negative draft system.

The control on the effecta lambda motherboard is such that the boiler is not allowed to cycle/idle during a burn cycle (as we all know, when a boiler which is originally designed for an induced draft fan is allowed to sit idle, with the fan off, it has no other option than to burn very inefficiently and with dirty/high emissions). In all actuality, when the fan is off the boiler cannot gasify at the normally high temperatures and becomes an expensive OWB. I used to own an EKO40 and any one who has one of these knows the problems that idling causes with the boiler.

In Sweden (who has some of the world's most stringent emissions requirement's) it is against the law to manufacture a gasification boiler that is allowed to cycle on/off during a burn. Thus, this forces the home owner to have a good amount of storage (1,000 gallons) for most size homes. Currently I have a customer with a 5,000 sq. ft home with lots of windows who is heating very well with an effecta lambda 35 with 1,000 gallons of propane tank storage.

I look forward to answering any other questions you may have.

EBU


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## TCaldwell (Mar 22, 2011)

Brian, so the draft inducer runs a one speed for the burn? how high of a co2% do you see at the onset of burn for average wood, and how long to recover to setpoint and how tightly is setpoint maintained  without a disturbance. thanks for the prior post. are you able to datalog co2 for a burn and post it, that would really be great!
  tom


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