DH4000 temp and humidity - water misters Vs venting air

[Dan_Shade]

I have a DH4000 kiln, with an autovent option installed that opens the vents to allow fresh air into the container when the temperature gets too high.

I am finding when it is hot outside, the vents will purge all of the moisture out, causing the relative humidity to drop (at least this is my hypothesis).  At any rate, I am having a tough time keeping the relative humidity where I want it when it is hot outside.

I am considering hodge-podging a misting set up to add water into the container, my plan is to use a pump up sprayer and open a valve to mist cold water into the unit on the exhaust side of the mounted fan units.

Have any of you guys done anything like this?

[GeneWengert-WoodDoc]

You are correct that when outside air is heated, the RH will drop right away.

So, you can turn off the compressor...the RH should be ok and the temperature will be too high, but as the wood dries more, it will use the extra heat.  You are at a low MC I suspect as the evaporation is not cooling or using enough energy.

Misting is ok, but in one breath you are evaporating and then the next adding moisture.  So, working on reducing heat seems like the best approach...maybe some cold water pipes, with fins, would work.

[DR Buck]

If I understand the DH4000 operation correctly, (I have one) when the RH is below the set point the compressor shuts off.  I also believe when the set temperature is reached the compressor also shuts off.   This would leave moving air from the fans as the only drying going on, and with external venting you may dry too fast.   I think adding the mister to raise the RH will help slow the drying rate.   But I would only do this if the MC of the load is high.    I usually don't worry about a low RH from over temp venting once the load is below a 25% MC.