for exhaust fan selection ? which type of fan Imust chose ? and I must provide duct in ground or in false ceiling?
Its usually easiest to hang the ducts from the ceiling. Need at least one vent over each station. The motor should be explosion proof. The exhaust vent needs to be outside the building on the downwind side or above the roof. Depending on National and local codes and the irritability of your neighbors you may have to put carbon filters or other scrubbing devices on it. Actually, you need a full engineering analysis from somebody skilled in the field.
This is a project for an experienced company that deals with ventilation and exhaust systems. Total CFM per station, a heat exchanger unit in the colder climates, necessary filtering, etc.etc.
If your aim is to regulate the level of fibre glass particles in air, inlet air should come in from the top and the exhaust should be removed from the floor level. If the air has to be recirculated (because of A/C) provide adequate filtration in the return path. If once through let the air out after using centrifugal separators and bag filters on the outlet. The fans must be designed for handling the required quantity of air with the filters loaded to at least 50% capacity.
