Quote Originally Posted by zw17 View Post
The other advantage is using it during dehydration of a system with a lot of moisture.

If you pull a vacuum to quickly and deep enough the moisture will freeze, leave your gas ballast open a pinch and you will pull a lot more moisture out without freezing it.
I had an issue with excessive moisture in a new install recently, and it was quite irritating. What point do you open or close the ballast? Does it add extra time? How effective is this method with relative humidity being >75%?