temperature question - first load through DH4000 Nyle/woodmizer unit

[Dan_Shade]

I have a small load in the unit now, with the humidity set at 85%, and the temp at 80 degrees.

It's not pumping much water out, and I wouldn't expect it to, but the temp has been hanging at about 113-115 degrees, is this normal?  I wouldn't expect it to make this much heat with the humidity set so high.

[OneWithWood]

What type of wood is in the charge?  How much?

[Dan_Shade]

about 300 bf of white oak

[OneWithWood]

Usually with a full load of oak I start out at 90°F and 80%.  It takes about 4-5 days to get up to the 110-113° range. 

If you would have said it was a load of tulip, aspen or pine I would have told you it did not sound out of line.  But with oak you may want to check the compressor for dirt or a blockage in the water discharge line.

Of course it may also be a function of the small load.  The heat may rise faster if there is less to absorb it.

[red oaks lumber]

what was the m.c.of the wood when you loaded the chamber?

[Dan_Shade]

not exactly sure of starting MC, it was a day or two off the saw.  Yesterday it was at 50%.

I didn't do an oven dry test until last week, and it was at 55% then

[Dan_Shade]

i've got a second load in the kiln now.  More oak, and some hickory.  aprox 600 BF of oak, and 250BF of hickory

I have the controller set at 85% and 90 degrees.  Put the load in on Thursday night, it hit 105 on Friday night, and 120 on Saturday.  The compressor is pushing about 10 gallons of water out per day or so.

I looked at the coils, and they are clean.  Is the temp rising this quickly because the hickory is letting water go quickly?

I raised the humidity setting yesterday evening to 90% to make the compressor not run so often, hoping the heat will drop down a bit.

[BBTom]

how much airflow do you have?  Are the fan motors generating heat?  turn off the compressor for a day and see what the temp does. 

[Dan_Shade]

Thanks for the response.

There are 2 fans in the box, and there is good airflow through the stack.

I'll try the compressor off route.  I'm afraid i'm pulling water out of the oak too quickly.

[scsmith42]

Dan, sometimes if your kiln chamber is extremely well insulated, the temperature can rise too quickly early in the drying process. This is not a good thing when you're drying green oak.

Your choices are to either turn off the compressor, or to vent some of the excess heat.  I've done - and do - both as needed.  Often times I will start the load at an even lower temperature - such as 75 or 80 degrees, in order to give myself some more leeway with respect to temperature rise.

When drying oak, try to keep the temp under 100F until you get below 35% MC.

Scott

[pigman]

Dan, I think you just bought a faulty kiln. ;)

[Dan_Shade]

yeah, it kinda smells like pig poop