Our computering system for the kiln dryer uses 4 sets of needles to check wood planks MC and dry + wet temperature in the room to determine the Relative Humidity (using psychrometric diagram)
We are based in Indonesia so the Relative Humidity in the air is high : 80%.
Problem : the computer inform us that we never get a low HR even when the room is running empty.
For exemple if dry temperature is 60 degrees Celcius (140 degrees Fahrenheit), the minimum
wet temperature obtained is 45C (113F).
Is it normal?
Also the water inside the water tank used to cool down the wet probe is hot so do we need to often change the water inside the tank to always have a normal water temperature 25 C (75 F) ?
Any help will be appreciate
You wrote "dry temperature is 60 degrees Celcius (140 degrees Fahrenheit), the minimum wet temperature obtained is 45C (113F). Is it normal?"
No, it is not normal even for your humid location. I suspect that something is keeping the wet-bulb from cooling off further. Three options: 1) There is not enough air blowing on the wet-bulb to cool it further. 2) The wet-bulb wick is not wet enough, so the available water evaporates and then the wet-bulb is no longer soaking wet, so it warms up. 3) The water used on the wet-bulb is too warm and is excessive, so that the bulb cannot cool off.
(Is the wet-bulb located about 5 cm above the water supply and does the wick supply water so that the wick is soaking wet? If there is enough air flow, the warm water in the wet-bulb box will not be an issue, as this heat will be lost as the water soaks up the wick.)
Thank you Gene for your advices.
I checked our drying room :
- the wick is always soaking wet
- water used on the wet-bulb is really warm (only 10 degrees celcius (50 F) below the dry bulb temperature)
I presume there is not enough air blowing on the wet-bulb. Could you please advice where is the best spot to put wet tank ? just after the fan ?
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