I need to pick somebody's brain

[Alabama_Mill]

I built a small dehumidification kiln big enough to dry 200 to 300 BD ft. I went budget friendly with this just trying to get my foot in the door trying to dry lumber I mill. Trying to see if there is a market for it around me. I have a 55 pint dehumidifier in it that I think had been doing pretty good. I have the wood dried down to 3 to 4% according to my moisture meter in 4 weeks. But the kicker is I can only get my temp up to 115 degrees. It ran anywhere from 90 to 100 with just the dehumidifier and then I added a small heater but it kicks off at 115. I have it insulated with 2" foam board and it is about as air tight as I could possibly get. Is 115 good enough for the sterilization process or do I need to get up to the 130? If I need to get it any higher any advice is welcomed. Thank y'all.

[WDH]

Your heater is most likely not designed to run at temp higher than 115 and probably has a high temp shut off.  115° is definitely not high enough to sterilize.  Typical consumer grade dehumidifiers and heaters are not designed to withstand the harsh environment in a kiln.  The acidic nature of the water evaporated from the wood will destroy them and they will not stand up to that environment over a long period of time.  The sterilization temp has to be over 133 degrees in the very center of the wood, not the air temp.  Many people, me included, run the sterilization temp at 150 degrees for 24 hours to ensure that the internal temp of the wood reaches at least 133 degrees and holds it there long enough to kill any insects, larvae, eggs etc.

[K-Guy]

You're lucky to get to 115°F, I believe manufacturers are required to build your typical residential and commercial heaters with a high temperature safety that cuts out at 104°F.

[farmfromkansas]

Yellow Hammer uses halogen work lights to heat his container.  I tried heaters, could not get enough heat.  My idea is to cut a vent in the container, and put the heater on the outside blowing in, also need ducting for a return.  That way the heater can put heat into an area that is hotter than what the heater cut off will run in.  I was thinking of putting a space heater shooting into the container with a vent open on the opposite end down low, get it hot enough then turn off the heater and close the vent. Rambling.

[Alabama_Mill]

I added one 250 watt heat lamp to it and it has come up to 117 over the last 3 days. I think I'm going to add another 500 watt heat lamp and put them both on a thermostat. I actually think that will work if I run them through the whole cycle. The temp came up while the wood was drying to 108 with just the dehumidifier running. The dehumidifier isn't doing anything now due to no moisture in the kiln. I'm going to try it and see what happens.

[scsmith42]

Great advice from others in this thread.  I'm questioning your results though.

What species are you drying, how thick is it, what type of meter are you using to measure the MC% and did the wood go into your kiln green or was it air dried?

[firefighter ontheside]

I too question your moisture content of 3%.  I doubt that is accurate.  If it is, that's not good.  Its too dry.
Theres no need to have your DH in the kiln while trying to reach 133 deg.  Take it out so the high heat doesnt' damage it.  I ran a space heater to get the temp up to around 100.  Then I turned on 2000 watts of light per YH advice.  I got it up to about 140 deg over 12 hours and the temp of the wood measured at around 133.  What's the outside temp?  I didn't even try to sanitize during the winter.

[Alabama_Mill]

I live in south alabama so my winters are not bad. Might have a few days in the low 30s upper 20s but never stays there. Even when we had that cold weather come through earlier this year kiln never got below 100. The moisture meter I have is not the best by no means. It is the pinless Dr Meter model md 918. Even if it close within 3% I should be good right?. I have some 1" thick long leaf pine in the kiln right now. I put it in there green. I took a board out and plained it down and checked it also and got the same reading. It's been in the kiln for about 6 weeks monday.i checked it when I put it in the kiln and it was around 30% I wanted to take the dehumidifier out but I have the plug run to the outside and I have it sealed up where the cord goes through wall. But I was thinking about doing it a different way so I could take it out.

[Southside]

You want SYP to finish at around 9%.  Any drier than that and it will turn to shards and tear out when planing, jointing, etc.  At a true 3% I would expect your planer to resemble the guy who chose the wrong Holy Grain in the Indiana Jones movie.  

[firefighter ontheside]

You want SYP to finish at around 9%.  Any drier than that and it will turn to shards and tear out when planing, jointing, etc.  At a true 3% I would expect your planer to resemble the guy who chose the wrong Holy Grain in the Indiana Jones movie.  

"He chose pooorly"