How are Positive Air Transients typically dealt with?
A. Relief Vent Sovent System – This system deals indirectly with the positive air transient slowing down the flow in the system thus preventing terminal velocity to be reached. Special aerator and de-aerator fittings must be used at each branch in order to prevent the formation of positive transients. Single Stack system – (Philadelphia system) – The Single Stack system relies on venting through the roof, with consequent increased roof penetrations.
