When drying your buds, you want the process to go slowly. If you put a fan on it or a blower to suck the air out your taking a chance for uneven drying.
The box you built is fine. You can even line the box with some cedar.
Some of the best methods I have found for drying are old school. Like wrapping up your buds with brown paper and placing your buds in a dresser for a week or so.
The way I dry is similar to your box. I converted an old kitchen cabinet into a dryer. I hang my buds in there for about a week until they are dry to the touch.
Then I cut the buds off of the stems and place them into cedar cigar boxes for 3-5 days.
At this point they are dry enough to smoke.
But if I wanted to I could cure it by placing small amounts into mason jars.
But I don't, I just leave them in the cigar boxes until it's time to bag it up.