POSITIVE PRESSURE ROOM
The Uniform United States Building Codes and the ASHRAE Hospital Guidelines are similar. The Building Code table allows the use of recirculated air if a HEPA filter is used.
Below I have tried to detail the recommended items to make a positive pressure room. Your room may be simpler or more complex. Different systems abound. They vary from the simple recirculation of air from a room unit and no supply air from the building HVAC unit to a very complex set of air ducts, balancing or motorized dampers. Call me with details when you have had a chance to review your systems with this information.
