Improve comfort and system performance - Achieve hydraulic separation between primary and secondary circuits - Prevent hydraulic coupling of pumps or pumps in series in primary secondary configurations - Prevent unanticipated or ghost flows in connected primary and secondary circuits - Control system is not affected by flow in a connected circuit - Integral pall ring microbubble high efficiency air and dirt separator eliminates separate air separator - Requires less mechanical room space than separate components Integral air vent pall ring technology has been used for many years in the processing industry. Taco’s application of pall rings to hydronic air and dirt separation is new to the HVAC industry. While air bubbles are separated by the pall rings through a process known as coalescence, dirt particles are actually caught and sifted to the bottom of the tank, where they can be removed through a blowdown valve. The 5900 Series provides higher efficiency, with reduced pressure drops, so a somewhat smaller pump may be used for maximum efficiency.