Agreed about the dehumidifiers not doing much below about 15 degrees but if the dehumidifier is in the cabinet and so are both its air inlet and outlet vents then there is a net heating effect from the machine itself as there are losses due to its inherent inefficiency and these appear as heat...
I built a drying cabinet some years ago - for fudge not wood but I'm sure the principle is the same - and found after some use that heating was not necessary and neither was ventilation.
The dehumidifier supplied all the heating and air circulation as long as both its inlet and exhaust were in...
