I am looking at building a Sound Proof studio, (internal dimentions about 14ft square by 8ft 6in high). Being sound proof means that it will be practically air tight and therefore I need to provide ventilation (by means of vents, extractor fans etc..). Does anybody know of a formula to give me the required throughput that should be provided (cu ft /hr). Bearing in mind this will probably be used by four musicians with associated amplifiers and other heat producing electrical equipment. Obviously the standard type things that you get for bathrooms would be totally inadequate (unless I used quite a few of them.) I would like to err on the over generous side as to add more ventilation later would be very difficult and expensive.