We're located in central NC & having condensation & humidity issues in the crawl space of our 2 year old home. It gets quite hot and very humid in the summer and we end up with a mess on our hands. The HVAC ductwork is in the crawl as well as our on on demand hot water heater.

I had posted a while back and we made some of the changes recommended--closing the vents, insulating the vents with rigid board insulation, running dehumidifiers. These measures have helped greatly, but the humidity level is still in the 64-70% range.

We've also done some more research. We keep hearing encapsulate the crawl space (to the tune of about $11K). But I also keep reading about odors over time and moisture under the encapsulating material. (Did I mention the $11K price tag?) But then the point is also made that in the south we didn't have these problems when we had greater ventilation under the house so the answer is to ventilate better.

The better ventilation end of the argument leads me to this company called Atmox. The have a sophisticated software system that supposedly measurea the humidity and dew point and turns the fans on or off depending on the readings. The end result is to bring drier outside air in to ventilate the space and keep things dry. They say a dehumidifier can be added to the system if needed. The cost is in the $2-3K range depending on if you do the install yourself or have it done turn key. I can't find alot online about them as a company other than someone on GW used them back on '07 or '09 and recommended them. I don't think its the company so much as the science behind it in any case.

We need to do something about this problem, but I don't want to waste money on a system that doesn't work or one that is overkill or one that I have to tear out a few years down the road.

Any insight into these options would be most appreciated.

Here is a link that might be useful: Atmox Vented Crawl Space Systems