People hear the word “kiln” and immediately shy away, assuming something that is too expensive, complex, or massive. But a wood kiln is not any of those things. Simple and effective, you just need heat lamps, a dehumidifier, a fan, and an insulated are to set it up.
Drying wood is one of those endeavors where the do-it-yourselfer can actually do a better job than the commercial guys. The businesses have time pressure to get product out the door, so they dry their wood quickly, often case-hardening it. Case-hardening is when the outer wood dries too quickly and it builds up tension as it shrinks disproportionately relative to the internal part of the board. Then when the board it cut, the internal tension causes it to twist and bow. The best quality wood is dried SLOWLY, at least 2 weeks if not longer.
I’ve not had any luck using a space heater in place of the heat lamps. Most heaters have internal thermostat protection and won’t run at the 120 degree temperature needed.