I removed the RVK 5" (240m3 p/h) extractor from the flower room and fitted it onto the output duct from the darkrooms cooltube/extraction/filtration setup in above pictures, to pull air out and draw LOADS of fresh air in via the DR's passive intakes, this fan is a bit over-rated for the size of the tent but it'l do, it sucks the sides of the tent in quite a bit