Carnes Company

Terminal Units > Bypass

Bypass Terminal Units

Model AB

The Carnes Model AB by-pass unit provides pressure dependent variable air volume to individual zones while bypassing the unneeded air to the ceiling plenum for recirculation. Although zone air volumes in small buildings may vary greatly, the cost of fan controls many times cannot be justified. Zone variable air volumes are realized with the by-pass unit while the supply fan delivers a constant CFM. The AB can be ordered for reverse or direct acting pneumatic thermostats or electric thermostats. Zone thermostats directly control the by-pass damper assuring that only the air that is needed is delivered to the zone. Downstream ductwork pressure losses can be matched by adjusting an integral by-pass balancing damper.