Zone 6a. This crawl is a addition to my kitchen. Its above grade, cinderblock walls, dirt floor, maybe 3 or 4 feet tall. I’m almost done encapsulating it. This is a area prone to radon. My levels are too low to worry about. (I dont know but I assume that could change with ground shifting, ect..) so I’m not tempted to open an area into the home as a just in case. And my friend freaked out saying something I didnt understand about negative air pressure if I had a vent into the house and then a exhaust fan to the outside as well. What should I do for it?