Closed loop systems create the need for accurate pressurization and air management in a hydronic heating and cooling system.  Unfortunately, proper air management often turns out to be an Achilles’ heel in a hydronic system’s design.  Design it wrong and a host of problems can erupt, from noisy operation to poor efficiency and shortened equipment life.  It begs the question -- why even design a system to be closed in the first place?  After all, condensate systems and cooling tower systems are