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Wood Mizer kiln settings

Started by Woodslabs, November 25, 2021, 05:47:34 PM

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Woodslabs

Hi all, 

I have the woodmizer kiln unit.  Currently the compressor turns on when the setting gets 2 degrees higher than what is set to.  I for example find that on my kiln at the beginning of the cycle the wet bulb stays around 86.7 or so.  So the compressor doesn't turn on unless I trick it by temporarily messing with the settings manually.  Is there a way to change this?  My kiln might have moisture leaks so may be why it wont get higher than that but it works well.  This is kind of annoying.

Anyone know if there is a way to reprogram it to turn on at 1 or 1.5 degree increase?
check out www.woodslabs.ca

K-Guy


There is but it will cause your compressor to start and stop a lot more and shorten it's life. We figured 2° differential was the best compromise. There should be in your manual or you can get our manual on our website. 
Nyle Service Dept.
A common mistake people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
- D. Adams

YellowHammer

What unit are you running?    

At your 86.7 WB, what is your DB?

If your WB is below the set point, and there is more than 10 degrees between the DB and WB temps, the wood is drying very well whether the compressor is running or not and will not stain white wood, which is a general rule of thumb.  

If you are not at a high enough or desired WB, or do not have 10 degrees separation, (Depression) then increase the DB by turning on the heat strips, and then as the temps come up in the kiln, either the WB will come up as moisture evolves off the wood, or the WB will stay the same, which means the wood is dry.  

The compressor doesn't dry the wood, it only removes moisture that has come out of the wood and has been absorbed by the air.  The difference between the WB and DB is what is removing the moisture from the wood.  

A leaky kiln is not a bad thing, except for energy costs, as it lets moist air out, which is all a compressor is doing.  However, leaky kilns require more energy to maintain the heat and temps required for the moisture to come out of the wood.  





YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

Swernicus

I had this same problem, and YH helped me identify that my kiln chamber had 2 big leak points allowing warm moist air to escape.  If your leaks are like mine then they are allowing too much moisture to escape and will not allow you to control your wet bulb temperature.  You will end up drying wood too quickly in the initial stages of drying, and may end up damaging your lumber.


Leak point 1 was my power and sensor cable penetrations.  I thought i had them sealed with putty but on a cold day i could feel warm moist air coming out of them and into the control box (not good!) a pretty good clip.  I spray foamed these from the inside and now they seemingly do not leak anymore.

Leak point 2 was my intake louvre (for L200 auto vent).  This was the main point of moisture escape.  The circ fans should blow against the inward opening louvres of the intake to keep them closed, but unfortunately alot of air was still coming through.  I was shocked at how much air was blowing through this vent.  As i was taping up the vent, there was quite a strong stream of warm moist air coming out as i got the to last strip of tape.

Leak point 3 is not an air leak but a liquid leak.  The bottom of my door seal will drip a ton of water at the beginning of a cycle as moisture is condensing there due to the colder temps right at the seal.  It appears spray foam overspray is not allowing the rubber seal to properly seat itself, so this is something I plan on fixing once my current cycle is over.  There's enough condensation leaking here to show a nice big wet puddle on the cinder block the kiln chamber rests on, especially in first drying phase.


Once you identify your leaks and seal up your chamber you'll see the WB will quickly climb to within 2-5 degrees of the DB easily provided your lumber charge is over 20%.  Like YH said, you still can dry wood with a leaky chamber however you likely will dry wood too quickly and risk case hardening or excessive warpage.  

My first 3 loads were done with a leaky kiln and I ended up with "usable" walnut lumber.  However I did notice that drying takes SO much longer at the very end when you over dry in the early phase.  The extremely dry shell of the lumber seems to lock in the core moisture so it takes a very long time to migrate out.  I dried walnut from 23% to 8% easily in about 15 days with a properly sealed chamber.  It took a similar load 30 or so days when i had a leaky chamber and overdried initially, and 2/3 of that drying time was spent watching the moisture probes stuck at 10-15%.

Mhaaland

This is good information!  Thank you for sharing.
What are you guys using for weatherstripping on the doors?
When you build the doors how much air gap are you leaving around them?

WDH

Nyle sells a door steak kit that works very well.  
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

K-Guy


@WDH 

Door Steak Kit??!!?   smiley_old_guy  smiley_nananana
Nyle Service Dept.
A common mistake people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
- D. Adams

WDH

I knew that you liked to grill......

(Door Seal Kit).
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

wkf94025

Any particular tips/tricks for leak detection?  Other than the obvious put your hand or face very close to suspect areas?
Lucas 7-23 swing arm mill, DIY solar kilns (5k BF), Skidsteer T76 w/ log grapple, F350 Powerstroke CCSB 4x4, Big Tex 14LP and Diamond C LPX20 trailers, Stihl saws, Minimax CU300, various Powermatic, Laguna, Oneida, DeWalt, etc.  Focused on Doug Fir, Redwood, white and red oak, Claro walnut.

Southside

Quote from: WDH on January 23, 2022, 11:19:06 AM
Nyle sells a door steak kit that works very well.  
Golden Corral does too.  :D
Franklin buncher and skidder
JD Processor
Woodmizer LT Super 70 and LT35 sawmill, KD250 kiln, BMS 250 sharpener and setter
Riehl Edger
Woodmaster 725 and 4000 planner and moulder
Enough cows to ensure there is no spare time.
White Oak Meadows

YellowHammer

Quote from: Southside on February 02, 2022, 12:31:54 PM
Quote from: WDH on January 23, 2022, 11:19:06 AM
Nyle sells a door steak kit that works very well.  
Golden Corral does too.  :D
Yeah, don't go to a Golden Corral when they run out of steak, or you'd better be ready for an all out brawl and be on national TV. :D


Yes, there are several ways to leak check a kiln.  If you have an infrared camera, rifle scope, or spotting scope, it's easy to see where the heat is making its way out, especially in winter.  You can also buy a cheap IR thermal imaging adapter for your iPhone, off amazon.

Another easy way is to use the way the big reefer manufacturers do leak checks....with an industrial smoke bomb.  They use a special kind that doesn't stink too bad, I got mine from the local reefer truck repair shop several years ago when I build mine.  I have also used military style smoke bombs, but they leave a nasty residue everywhere.  You could use any kind of smoke, you just need a lot of it.  

Another way is to turn off the lights, go inside, and have someone lock you in.  Then look carefully for any daylight coming through cracks, door sills, vents, etc.  I do this routinely but I trust my wife to not keep me locked in. :D

Also, in the winter, look for where condensation is forming, as the water in the hot moist air will condense out when it hits cold air, and that's a leak or a lack on insulation.

 
YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

K-Guy


The best thing I know of for leak detection is a Thermal Imaging Camera, best used at the end of a cycle at a cooler time of day.
Nyle Service Dept.
A common mistake people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
- D. Adams

wkf94025

Great suggestions @YellowHammer .  I will employ those.  Yes, I have an IR camera adapter for my phone.  It hasn't found any smoking guns yet.  I like the daylight analysis from inside approach.  Also, I have a smoke machine for detecting boost leaks on my 911 and Powerstroke, still new in box.  I wonder if it's output is sufficient for a kiln of 22' x 8' x 5'.  Guessing not.
Lucas 7-23 swing arm mill, DIY solar kilns (5k BF), Skidsteer T76 w/ log grapple, F350 Powerstroke CCSB 4x4, Big Tex 14LP and Diamond C LPX20 trailers, Stihl saws, Minimax CU300, various Powermatic, Laguna, Oneida, DeWalt, etc.  Focused on Doug Fir, Redwood, white and red oak, Claro walnut.

K-Guy

Quote from: wkf94025 on February 03, 2022, 04:50:29 PMkiln of 22' x 8' x 5'. 


What model do you have? If it is a KD150 you will probably need more heat.
Nyle Service Dept.
A common mistake people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
- D. Adams

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