The Forestry Forum

General Forestry => Drying and Processing => Topic started by: xlogger on November 21, 2019, 06:09:39 PM

Title: maple in kiln
Post by: xlogger on November 21, 2019, 06:09:39 PM
Monday I put a load of maple slabs in my kiln, they where around 20-21%. I got maybe only 2 gallons of water in the bucket the first two days. Today it's real slow drip, I open the door and it fog my glasses right away. I open the screen to look at coils and very little water on it. Check mc got around 20%. I would think it should be a good drip with that. I try calling Stan but he must be out of the office today. dp 120 wb 75.
You think it might need charging, low on fluid?
Title: Re: maple in kiln
Post by: YellowHammer on November 21, 2019, 11:07:45 PM
Do you know what the actual wetbulb temp was?  What was the moisture loss in the wood?

The compressor has a low pressure shut off that will turn it off if th Freon gets too low.  However, you may have a low charge.  

If your system is working properly you should be able to reach in past the filter and feel the evaporator coils, they should be cool but not freezing.    
Title: Re: maple in kiln
Post by: K-Guy on November 22, 2019, 08:38:08 AM
Hi Ricky
Sorry I was running around like a chicken with her head cut off yesterday. I'll call you in a bit.
Title: Re: maple in kiln
Post by: Southside on November 22, 2019, 09:02:39 AM
 :o that has meaning around these parts! 
Title: Re: maple in kiln
Post by: K-Guy on November 22, 2019, 10:09:01 AM
Quote from: Southside on November 22, 2019, 09:02:39 AMthat has meaning around these parts!


No chickens were harmed during my day. By the end of it I was to tired to chase them!! bat_smailey

I would of said something else if I had remembered your chicken fetish.  crow_smiley
Title: Re: maple in kiln
Post by: WDH on November 22, 2019, 09:39:45 PM
Some things that you learn at The Project are better off left at The Project :D. 
Title: Re: maple in kiln
Post by: Southside on November 23, 2019, 07:56:25 AM
Folks names being one?   :D
Title: Re: maple in kiln
Post by: GeneWengert-WoodDoc on November 23, 2019, 07:56:47 AM
When a thick slab is at 20% MC, it will be drying slowly, especially when at 120 F.  How much wood do you have in the kiln?  Sometimes, even with low RH, air dried wood will go into the kiln and appear not to dry.  Actual, the surface is so dry, that humidity is a slow driving force.  You need heat to get the water moving.

What is the RH?  If it is too high, then the compressor is not removing moisture.  Are the coils cold?  If not, then what is making the compressor not work...automatic shutoff due to high temperature, low refrigeration fluid, compressor seals no longer working, etc.

If the temperature outside is 55 F, your glasses will be at that temperature, if the kiln has 120 F dry bulb and 80 F wet-bulb (low humidity), or any WB over 55 F, you will fog your glasses, even though the kiln is indeed  dry.  So, what is the RH?  

If you have a pin moisture meter, take a thin piece of wood, maybe 1/8" thick and stick the pins into that.  Then put the meter with the wood on the pins into a closed plastic bag and  put it into the kiln.  This is to let it warm up without getting condensation.  Then in an hour, take it out of the bag, wait another hour and then measure the MC of the thin piece, making temperature and species corrections.  That will be the EMC, which you convert to RH.
Title: Re: maple in kiln
Post by: WDH on November 24, 2019, 07:20:39 AM
Quote from: Southside on November 23, 2019, 07:56:25 AM
Folks names being one?   :D
OK Bob, you score a point on that one.