Can this be mounted on 24" Center Joists without cutting the joists to form the mounting box? (i.e. can I nail cross members between 24" Center Joists and mount this fan without having to cut the joist? )
looking for a whole house fan to replace an existing unit. We have a rough opening of 32" X 32". I could not find a rough in size on the listed fans. They seem to be sized by fan blades and not rough opening size.