Two story residence in WV with cold winters, mostly hot, humid summers, HVAC on both floors and lower level mostly below ground level. Plastic under concrete floor and some insulation on basement level walls. House is rather tight construction for the 70’s construction.. Have an installed pipe from below basement concrete floor to above roof with in-line radon fan. Had minimal effect on radon reduction which is at or just above recommended levels to take action. Intend to add exhaust ports in that stack in basement hallway. Would you recommend two entry ports or only one at about 12 inches below the ceiling? Would it be better to have two entry ports, one as mentioned and another at the floor level which would allow closing one during seasonal conditions, like during winter, closing the upper and leaving only the floor port open? Have one prepared for install, and it has a screw-in stop to close it down. Need someone’s recommendation. Thanks.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part