Question about adjusting an EKO 40 gasification boiler for higher elevations

[Firefighter Bob]

Greetings Everyone:

I installed my new EKO 40 gasification boiler and have been burning very dry pine. I live at 7,000' and am concerned that because the air pressure is so much lower here than, for example, at 500' above sea level, that I need to adjust the air inlets to feed more air into the upper and lower chambers to approximate the amount of air it would normally receive at a lower elevation, thus making the boiler burn richer / hotter. Does this sound correct?


The EKO 40 has 3 air adjustments: the blower (regulates how much air is available to both primary and secondary combustion chambers), the primary inlets (regulates how much air is available to the upper “primary” combustion chamber, where the fuel undergoes pyrolysis) and the secondary air inlets (regulates how much air goes into the steel tubes where it is superheated before being used by the nozzle to achieve secondary combustion and gasification).


The blower:
When I checked the blower’s stock air control setting, it appears to be open about 0.95" on 2 sides which equals 1.90" of total opening out of a total possible "full" opening of 5.396" (which is 1/2 the total circumference of 10.79") which means that the factory setting is about 35% of the total possible full or 100% open setting.


Primary and Secondary Air Inlets:
The primary air inlet is factory set to 9mm width and the secondary is set to 3 “turns”.


According to charts I found online, my elevation of 7,000' has an air pressure of about 78.19 kPa compared to a 500’ elevation (which I will use as my baseline) of 99.49 kPa. The difference in air pressure is about 0.786, which means that if I increased my air intake adjustments by about 1.272 (or 27%), I would increase my air intake volume to match that as found at 500’ elevation. Is this correct or have I made mistakes in my math / assumptions? Thank you for reading my questions and for any help or suggestions you can provide!

 

[Como]

I can not answer your question for the EKO. I did ask the same thing about a couple of Boilers I am looking at, the Garn can be supplied with a bigger fan, I have seen that work at 7,000ft, the techie ones can self adust but I did not follow through to how much/ actual experiances.

 

[Gooserider]

Not sure, but you may be over thinking this - remember that you have lower pressure on the chimney side as well as the air intake side, so the altitude may tend to cancel out... Mostly I would say that you need to evaluate based on the way the boiler is running, not so much on your altitude.

I would probably start by going through the "Fine Tuning the EKO" sticky on the first page, if you haven't already done so - there may be some discussion in there about altitude, I forget as it's been a while since I've read it. At any rate follow their advice on how to adjust for optimum gasification flame, and you should be fine...

Gooserider

 

[stee6043]

Definitely check out the thread Goose mentions above. My quick tip would be to leave the primaries, maybe go another turn or two out on our secondaries and open your fan blades to 100%. Use the controller to bring your fan speed down as needed. Many of us EKO guys run 50% fan speed much of the time (except when starting)....

 

[Firefighter Bob]

Thanks everyone, I will check the thread and I enjoyed reading your comments. Yes, I may be over thinking this issue.

Some of my cut pine has been down for several years and is below 10% moisture. Does anyone have thoughts about using wood that is too dry... the pros and cons? Thanks.

 

[Gooserider]

Thanks everyone, I will check the thread and I enjoyed reading your comments. Yes, I may be over thinking this issue.

Some of my cut pine has been down for several years and is below 10% moisture. Does anyone have thoughts about using wood that is too dry... the pros and cons? Thanks.

You can sometimes get a bit of an overfire condition if you light off a stuffed firebox of overly dry wood. Pine and other softwoods are more prone to this anyway just because they tend to burn fast anyway... It isn't a "disaster waiting to happen" sort of problem, just mostly something to be aware of... Probably the easiest thing to do is if you have some less than perfectly dry wood, just mix the two together to get something approaching a nice "average" moisture level for the entire load...

Otherwise, probably avoid overstuffing the firebox, and maybe run a bit less air going into the upper chamber...

Gooserider

 

[Firefighter Bob]

Thank you Gooserider! I agree and have already mixed some wood that has only been down for about 6 months with my very dry wood... seemed to improve things.

Once I got use to the idea of all that potential energy inside my new boiler, I'm starting to enjoy firing it and fine tuning it. I've just spent some time reading various past threads as you suggested... there's some very bright people on this forum making good observations and good suggestions.

 

[Duetech]

Firefighter Bob, I have burned both well seasoned and questionably seasoned pine in my EKO40 as well as seasoned oak, hickory walnut and elm. The adjustments on the EKO make it so you can get a wide range of settings. In my experimenting and resultant experience I can get a blue flame with any wood I burn. Overfireing like Gooserider suggests is not a disaster waiting to happen but will definitely burn up your load (also evidenced with an orange flame at peak gasification). Overfireing can also happen when your slipts are too small in diameter and bridging (about the equivalence of underfireing) can happen when the splits are too big. The big thing to look for is the blue flame which is best found with a healthy bed of coals and with a load that has been in the upper chamber for at least an hour. Your flame will vary with fresh loads and fire starting as the boiler will be cooler but you should not need to adjust the air mix. Just blower velocity when starting a fire. With dry wood pine or oak or what ever I don't fiddle with the mix settings it's mostly in the split sizing.

 

[Firefighter Bob]

Thank you Cave2k. I have been mixing really dry with kinda dry pine and it seems to work well, but I haven't pushed the envelope or tweaked the air inlets to see how long a burn I can achieve.

Another question... do you or anyone else reading this have experience with New Horizion's "Draft Booster"? I have a non-variable speed DB and have tied it into the controller's fan control... so when the main fan runs, slows or stops, the DB does as well. The DB works fantastic when starting a fire, but I'm wondering if I'm moving too much air with the booster installed. I wired it so I can independently turn it on, off or run it automaticly. Any thoughts on when to use and not use the DB? Many thanks.

 

[Hydronics]

I have his (zenon's) draft inducer, I use it only when loading to reduce smoke in the face & when starting. I wouldn't use it for normal operation, the blower will move more than enough air by itself. They are designed to work this way, & I haven't experienced them being inadequate. I (and others) actually run @ 50% fan speed to prevent bridging, I don't need the full output anyway.

 

[Firefighter Bob]

Thank you Hydronics, for the good advise. Sorry to sound stupid, but what is "bridging"? Many thanks.

 

[Hydronics]

No problem Bob,
Bridging is when you burn away the coal bed and the wood is left above the refractory & not in contact with anything hot enough to begin the pyrolisys process. Basically the wood is hung up with a space between it & the nozzle. Personally, I haven't had an issue with this but others here have.
How do you like your EKO?
Regarding your concern with elevation: Higher elevation effects combustion due to a reduced oxygen content per volume of air. The lower atmospheric pressure = less pressure to compress the natural air = less oxygen/volume. This will have an effect though I believe it would be minimal, in theory you'll need a bit more overall air flow -maybe open the fan shutter another 10%.
I'd tune for a good flame in the middle of a burn cycle. Be sure to wait until you have a week or so of burns on it to dry out the refractory or you'll be chasing your tail. Personally, the factory settings work well for me overall. Remember, the fuel (wood) is not consistent like gasoline. It changes by species, moisture content & will change through a burn cycle. It's not consistent/precise in the way carburetor adjustment is.

 

[Firefighter Bob]

Thanks Hydrolics... terrific comments! "Bridging" makes perfect since. You could also say that you have an "air-gap" between your fuels, or in firefighter speak, a loss of heat "conduction".

I'm a first time wood boiler user... was a little intimidated in the beginning, but I'm getting more comfortable running the boiler over the past week+ of firings. I really like the boiler and have had few problems getting it burning, but have only been seeing temps in the 165+. The only adjustment I've made so far is with the blower... opened the shutter from the factory setting of about 35% to about 50%. I like the controller, but haven't changed any of the factory settings. I added two DPDT switches into the front panel (near the controller) to allow me to independently control my pump and my draft booster... off, on, automatic.

Being a firefighter (structure, HazMat, wildland, EMT), I understand about the wood (fuel) issues. I hope to use mostly pine because I have 10 acres with about 6,000 trees... plenty of free fuel. I may try to get some oak or aspen to add to my pine to boost fuel BTU's.

 

[taxidermist]

I have his (zenon's) draft inducer, I use it only when loading to reduce smoke in the face & when starting. I wouldn't use it for normal operation, the blower will move more than enough air by itself. They are designed to work this way, & I haven't experienced them being inadequate. I (and others) actually run @ 50% fan speed to prevent bridging, I don't need the full output anyway.

Just to be clear Hydronics has a eko 60 not a 40 and you say you run at 50% fan speed with 2 fans? The 40 only has 1 fan that would be running at 100% I know some that run the 40 at 50% after a good bed of coals is in the fire box. I have a eko 60 and only use 1 fan and run it between 50 and 100%


Rob

 

[Firefighter Bob]

Thanks Taxidermist. Yes, I have one fan in my EKO 40 with the shutter currently at 50%. When you speak about your fan settings, are you referring to speed or shutter openings or both?

Yesterday, after it was running for several hours, I loaded some more wood and noticed that I had a nice, rich, glowing coal bed. The secondary chamber flame seems orange, so I was thinking about opening the secondary jets a little to richen the mix. I haven't adjusted the fan speed but may experiment with it in the near future. Any suggestions on adjustments for the 40? Thanks!

 

[taxidermist]

Thanks Taxidermist. Yes, I have one fan in my EKO 40 with the shutter currently at 50%. When you speak about your fan settings, are you referring to speed or shutter openings or both?

Yesterday, after it was running for several hours, I loaded some more wood and noticed that I had a nice, rich, glowing coal bed. The secondary chamber flame seems orange, so I was thinking about opening the secondary jets a little to richen the mix. I haven't adjusted the fan speed but may experiment with it in the near future. Any suggestions on adjustments for the 40? Thanks!

/


Bob,

The first thing you should do is get a moisture meter and figure out just what is the average moisture in the inside of your wood. Take a ound and split it and check it for moisture. This will give you and idea of what you have. You need to find a average for your wood pile. It is also a good idea to figure what king of draft your chminey has while your boiler is running, this could change all the time(this is why I use a barometric damper). Then look at your chart on pg 18 in your manual and adjust the settings acording to your moisture of wood and your chimney draft. You can still get it real close with out getting real fancy with manometers and as the numbers on the chart are all real close. I run my fan shutter all the way open all the time If you look at the chart for the EKO 40 it says 100% air blower opening across the board. If I am running real good and have a nice bed of hot coals I will turn the blower speed down depending on how my moisture is in my wood.The higher the moisture the more air you need.
Hope this helps,by the way I am also a firefighter from Michigan.

Stay safe Rob

 

[Firefighter Bob]

Thanks Taxidermist, I appreciate the suggestions and conversing with a brother firefighter!

 

[Hydronics]

I have his (zenon's) draft inducer, I use it only when loading to reduce smoke in the face & when starting. I wouldn't use it for normal operation, the blower will move more than enough air by itself. They are designed to work this way, & I haven't experienced them being inadequate. I (and others) actually run @ 50% fan speed to prevent bridging, I don't need the full output anyway.

Just to be clear Hydronics has a eko 60 not a 40 and you say you run at 50% fan speed with 2 fans? The 40 only has 1 fan that would be running at 100% I know some that run the 40 at 50% after a good bed of coals is in the fire box. I have a eko 60 and only use 1 fan and run it between 50 and 100%


Rob

Rob, I run only 1 fan and only nozzle (the back one blocked) I run the fan @ 50%. Essentially it's equivalent to ta 40: 1 1"x8" nozzle and one fan. The 60 has more btu than I need currently, but won't when I get the storage set up.

 

[taxidermist]

I have his (zenon's) draft inducer, I use it only when loading to reduce smoke in the face & when starting. I wouldn't use it for normal operation, the blower will move more than enough air by itself. They are designed to work this way, & I haven't experienced them being inadequate. I (and others) actually run @ 50% fan speed to prevent bridging, I don't need the full output anyway.

Just to be clear Hydronics has a eko 60 not a 40 and you say you run at 50% fan speed with 2 fans? The 40 only has 1 fan that would be running at 100% I know some that run the 40 at 50% after a good bed of coals is in the fire box. I have a eko 60 and only use 1 fan and run it between 50 and 100%


Rob

Rob, I run only 1 fan and only nozzle (the back one blocked) I run the fan @ 50%. Essentially it's equivalent to ta 40: 1 1"x8" nozzle and one fan. The 60 has more btu than I need currently, but won't when I get the storage set up.

Yeah mine is oversized for my house but when I start to heat my barn it will be fine. I did the blocked nozzle thing too but took it back out after about a month.