Ventilation Purified Air Limited manufacture turn key systems to suit any application. There are many requirements for ventilation, listed below are options that are available:- FILTRATION - VARYING DEGREES FRESH AIR SUPPLY RECIRCULATED SUPPLY TEMPERED OR HEATED AIR COOLED AIR Each application has to be viewed separately dependent upon what needs to be achieved and if there are any energy or flow constrictions. Suffice to say that Purified Air can provide a design for any application.