Hello everyone. I am a first time poster. We have been in our new home in North Carolina about 6 months now. We have Ash hardwoods throughout with the exceptios of the bedrooms. In the summer we had moisture in the crawl space, mostly on the hvac, due to the terrible humidity here. I put a heavy duty dehumidifier in the crawl and piped the drain to the outside of the crawl space. My builder also insulated the vents. That took care of the moisture. However, now that winter is here, sometimes we hear random pops from the floor. It does not happen all the time and I do not see any gapping. Do I have it too dry in the crawl space? I have also noticed my crawl space is now pretty cool in the summer and pretty warm in the winter time compared to outdoors. Could this play a role?

Without a thermal hygrometer, it is all guess work.

too dry in the crawl space?
No.
I'd be thinking you got a sub-floor that ain't too flat enough