Patent ID: 8936203
Filing Date: 2015-01-20
Classification: F24F

Abstract:
1. A control system for an HVAC system serving at least two zones, each zone receiving conditioned air by way of a zone duct leading from the HVAC system to the zone, the control system comprising: a zone thermostat located in each zone, a zone damper located in each zone duct configured to control the flow of conditioned air through the zone duct in which the corresponding zone damper is located, the zone damper including a shell situated in the zone duct, a damper blade pivotally mounted within the shell, the damper blade having an upper portion sealably engageable with a first segment of the shell and a lower portion sealably engageable with a second segment of the shell, the upper and lower portions of the blade being separately movable with respect to each other, and an actuator coupled to each shell and responsive to the corresponding zone thermostat, the actuator being coupled to the upper and lower portions of the damper blade to cause movement of both of the blade portions in response to a call from the corresponding zone thermostat for conditioned air in the corresponding zone, wherein only one of the upper and lower blade portions is configured to be responsive only in a single direction to any HVAC system static pressure differential in the duct to open and bleed an amount of conditioned air past the damper when the static pressure differential of the system increases above a selected level due to a continuing supply of conditioned air to another of the zones.