Sealed vs vented crawlspace under an insulated floor – GreenBuildingAdvisor

Hey there Building Science Enthusiasts!

I am building a straw bale panel house in Columbia, Missouri where we have hot humid summers (very much the case right now haha). I am normally all about sealed crawlspaces – the humidity in the cool soil here in Missouri under a house will most certainly cause water precipitation when vents are introduced; allowing hot, humid, and cool air and surfaces to all mix.

The thing with this house though, is the floor is very insulated. The two pictures attached are a single wall panel (not super necessarily for this discussion but that shows you how straw bales are used) and also all of my floor panels. Floor panels are basically 2×12’s with straw stuffed in them. The floor panels are somewhere around r-30 or so, albiet with some thermal bridging with the 2x12s. The bottom of the floor panels will have a vapor-open weather barrier like Henery Blueskin or Adhero (ideal house wrap for straw bales).

My question to you is: to vent or not to vent the crawlspace? What areas are at risk for seeing water precipitate in a vented crawlspace with an insulated floor? Sealing the crawlspace would certainly be more work and cost, but is it necessary?

Excited to hear your responses!