All, thank you. Karen, the test (by others) came back at 12 above the crawl space. The crawl was not power ventilated. Rooms above the garage were not tested. (I'd like to get a clarification on testing in rooms above a garage and slabs on grade with basements in NOLA, I think protocols recommend it, but not required). I will push for testing rooms above garage now, get an idea of slab influence. I haven't visited the property, going by photos and realtor (a really good one), and I agree, there shouldn't be pipes in inaccessible crawl, but there may be limited access. I like temp controlled fan, but exhaust needs to be up and around eave? Thanks again, all.