measuring air flow?

[David Mealey]

Hi Folks,

A question for you old timers. If temp., RH% and airflow are the big 3 key factors in proper kiln drying, are you measuring your air flow velocity? If so, how? A quick Google search shows a couple of hand helds from Grainger for $170-$471.00.

My reason for asking is that I'm getting some wet pockets in my boards and slabs. Local experts point to uneven airflow as the likely culprit. Aside from even distribution is there an average velocity that is ideal?

Thanks,

David M.

[Jim Andrew]

Explain about your kiln and fans.

[Tom Bender]

Since you only need to carry off any evaporation, which happens very slowly, very low velocity should be adequate. The trick is getting airflow over every square inch.

[David Mealey]

Hi Jim,

My kiln sits inside a 2500 sq. ft. barn and is approximately 16' wide, 12' deep and 18' tall, insulated to about R-30 with an EBAC LD800 DH. I can get a maximum consistent 115-118 F temp with the EBAC and some small reflective heaters. I have three fans alongside the EBAC blowing across the top of the stacks and then 3 smaller fans on the bottom front of the stacks to circulate the air back towards the EBAC unit. There is a baffle that is adjustable on the top of the stacks but none on the sides of the stacks. Right now I have about 1000 bf of 4/4-5/4 white oak and 4/4-/5/4 black walnut cooking. There is quite a bit of leakage in the front slider doors which I've tried to minimize with a tarp barrier.

[Jim Andrew]

You would probably have better response on Forestry forum.com, there is a section on drying, and the wood doctor resides there.