We are building three sound insulated classrooms which will be fairly well sealed. There will be no open windows so we're to use mechanical ventilation. I live in a warm country so heating isn't a consideration.
My understanding was that we would have air extracted through ceiling vents by a motor outside the building. Air would be supplied from vents on the ceiling on the opposite side of each room drawing through ducts from an indoor patio using suction created by the same motor.
We contacted two hvac companies who both tell us we should have a second motor to pump air into the rooms which is pretty expensive.
Is this really necessary or do we just need a slightly more powerful single motor?