humidity in solar kiln?

[xlogger]

On the Nyle L53 is it only use as a DH or does it also heats? Also is it ran off 110 volts? Maybe I should send off for info and prices, not sure if I'd be interested in using one in my next project or doing it way I plan.

[WDH]

Yes, the unit has a heater built in to supply heat.  Once the compressor begins to run, and with the additional fans, more heat is generated from the motors to keep the temps at or above the operating set point.  I only use the heater to initially bring the kiln to 80 degrees (compressor needs 80 degrees to run) and at the end of the cycle to sterilize the load when the compressor has been turned off.

The unit runs on 110 volts. 

[xlogger]

That sounds like it could work well with my OWB supplying heat. Might not never need to use the heater in it, maybe just to get temps up over 135°. Using it over a house DH unit or maybe 2 in kiln, what would be more of an improvement over the cost? I expect the price of one is a lot higher than a house DH.

[WDH]

Higher cost, but it has set-point controls for precise drying.  It is built to handle the harsh environment for drying wood.  I dry about 1500 BF per month in mine.  If you pre-air dry, much faster and more efficient than solar.  Dries wood 24 hours of the day, not just during the daytime.

[YellowHammer]

The L53 is a good unit, it will dry most types of 1 inch thick wood right at the max moisture removal rate, depending on load size.  There are several posts on the Forum concerning it, and I have dried many, many loads of wood with mine, and it does a fine and fast job.  While it may cost more in power consumption over a homeowner DH, that is offset in production rate.  I get a load of wood out of mine every 7 to 10 days, including sterilization, with load sizes from 300 to 900 Bdft. 

[xlogger]

YH, you told me once to air dry as much as you can before putting in kiln. Is the rate of 7-10 days with air dried wood? What would be a guess on drying maple 8/4 that is put in kiln with MC around 15-18%? I know it can range in time but maybe an average? I looked at your picture of kiln. My plan as of now on the next one is 14 wide to hold 12 ft boards, not sure on how deep. At least 10 ft or 12 ft. At 12 ft I could put two racks of wood in if needed for storage if not using the kiln, I don't have a dry room for kiln dry wood. There seem to be a never ending process of things you need.

[YellowHammer]

I'd guess two or more weeks for maple, including sterilization, but I wouldn't put 20% 8/4 thick in my Nyle DH, I would air dry as normal to well less than 30%, to get it past the critical 35% ish stage, then I would put it in my solar kiln to bring it down to less than 10% still going slowly, but taking advantage of the additional heat input of the solar kiln to accelerate the process over straight air drying, and then finish and sterilize the 8/4 in the Nyle DH kiln in a week or so, max. Solar kilns are very good at drying wood slowly, and that can be controlled by load size and the additional use or disuse of an auxiliary dehumidifier, so it's perfect for drying slabs that have a decent and forgiving maximum moisture removal rate.  So I use the three different drying processes (air, solar, and the DH) to safety dry the thicker wood at a relatively efficient rate, while conserving electrical power and still only tie up my DH kiln for an absolute minimum amount of time.

So in reality, I never want my DH kiln(s) tied up for more than a week or so with a single load, so I will use these other techniques, adjusting for species and thickness, to get the wood down to where I'm pretty sure it will be done within that time period.

There is no doubt it takes some covered open air space and a little more overall time per load for this kind of musical chairs rotation (and a forklift) to get thicker stock dried relatively quickly, but it sure beats waiting for air drying, or cracking it to kindling by pushing it too hard.  I like to saw up at least one rotation ahead, or keep one stack air drying and ready for the swap.  I've got some really nice, wide 8/4 cherry slabs that were cut just a few months ago now idling at about 8% in the solar kiln, and they will go into the L53 as soon as the 4/4 load of red oak load in there now comes out, this weekend.

I wasn't sure what use I'd have for the solar kiln after I got the second DH kiln operating, but so far this seems to be working very well.  Drying the thicker slabs gives me an excuse to keep my solar kiln in service, and only costs me the electricity of a couple $20 window fans.

[xlogger]

That's kind of what I had plan on when I got around to building another kiln. I cut some cherry yesterday and today and put in under the fans like I did the maple. I'll leave it there for a week or two before I move it. I've got the ambrosia maple in solar kiln now, its around 14%. Got someone waiting on it when I can get it around 8%. My DH put out a lot of water to start now I'm not getting much water, the RH in kiln stays in low 30's or in the 20's.

[Glenn1]

Hey Ricky,

I've been told by YH that cherry does not like fans.  I did not use fans on my cherry and it came out looking very nice. 

Glenn

[YellowHammer]

Hey Ricky,

I've been told by YH that cherry does not like fans.  I did not use fans on my cherry and it came out looking very nice. 

Glenn

I would definately not use the fans.
Fans are mainly to prevent sticker stain and accelerate drying, and cherry is very immune to sticker stain and although it's pretty forgiving, doesn't like to be dried too fast.  Cherry is also very prone to cracking and splitting, and fans will aggravate this, especially anything thicker than 4/4.
Every species has its own personality or sweet spot, conditions under which it dries and produces the best quality and color. Cherry likes a nice, quiet spot to think and relax while its dries...
Oddly enough, air dried cherry does not have a tendency to stall out in a kiln like red or white oak.  It will give up its water very predictably and easily until it's dry. So it air dries pretty fast compared to some other hardwoods.

[xlogger]

going out and cutting fans off now ;D

[xlogger]

I got fans of now thanks. So that changes my sawing today. I was going to cut some walnut mantles but now that I have my fans free I'm got some more ambrosia maple that I will cut.
YH, I think it was you that I heard saying about stacks 4 ft wide are top heavy and will tip. I came real close moving my cherry lumber yesterday to turning it over. I would of cried  :'(.
Glenn, I'm want to get up your way soon. I'll pm you and give you a call. Ricky

[GeneWengert-WoodDoc]

There are many safe combinations of fan speed (velocity of air through the load) and relative humidity.  So, with cherry that is drying too fast and developing cracks and checks, you can raise the humidity, drop the air flow, or a combination of both.  One advantage of fans is that they stir the air up so that the entire load sees the same humidity and temperature, so it is all drying about the same.

One way to use fans is to run them part of the time, rather than 100%.  I have also seen fans that are driven with a fan belt and pullies, and these fans have two sets of pullies so the speed can be adjusted.  Finally, large kilns often have a speed control on the fans that changes from 60 cycle electricity to slower cycles, which slows the fans and saves electricity.

Experience shows that running only some fans and shutting off the others does not work well at all.

[WDH]

You can also orient the fan to blow parallel to the stack to have less direct impact on the lumber, but still create a gentle air flow. 

[xlogger]

I got fans off now thanks. So that changes my sawing today. I was going to cut some walnut mantles but now that I have my fans free I'm got some more ambrosia maple that I will cut.
YH, I think it was you that I heard saying about stacks 4 ft wide are top heavy and will tip. I came real close moving my cherry lumber yesterday to turning it over. I would of cried  :'(.
Glenn, I'm want to get up your way soon. I'll pm you and give you a call. Ricky

[xlogger]

I hit the wrong button on the post above. Trying to correct my spelling. I going to start on my new kiln today. Got wire to run out to it and going to check on prices on Nyle kilns also.