Backdraft damper with electromagnet for terminal unit

Abstract

A terminal unit for a HVAC system, including: a housing including a first chamber configured to receive a first air flow and a second chamber configured to receive a second air flow; an internal wall disposed within the housing and extending between the first chamber and the second chamber, wherein the internal wall includes an opening formed therein; a damper door rotatable relative to the opening, wherein the damper door is configured to occlude the opening in a closed position; and an electromagnet that is configured to be selectively activated to generate a magnetic field to retain the damper door in the closed position and thereby prevent the first air flow from flowing through the opening; wherein when the electromagnet is deactivated, the magnetic field is not generated such that the second air flow may be forced from the second chamber to the first chamber through the opening.

What is claimed is: 
     
         1 . A terminal unit for a heating, ventilation, and/or air conditioning (HVAC) system, comprising:
 a housing comprising a first chamber configured to receive a first air flow and a second chamber configured to receive a second air flow;   an internal wall disposed within the housing and extending between the first chamber and the second chamber, wherein the internal wall comprises an opening formed therein;   a damper door rotatable relative to the opening, wherein the damper door is configured to occlude the opening in a closed position; and   an electromagnet that is configured to be selectively activated to generate a magnetic field to retain the damper door in the closed position and thereby prevent the first air flow from flowing through the opening;   wherein when the electromagnet is deactivated, the magnetic field is not generated such that the second air flow may be forced from the second chamber to the first chamber through the opening.   
     
     
         2 . The terminal unit of  claim 1 , comprising a control system configured to supply electrical current to the electromagnet to activate the electromagnet. 
     
     
         3 . The terminal unit of  claim 2 , wherein the control system is configured to supply power to a blower to selectively generate the second air flow. 
     
     
         4 . The terminal unit of  claim 3 , wherein the control system is configured to supply the electrical current to the electromagnet based on an operating state of the blower of the terminal unit. 
     
     
         5 . The terminal unit of  claim 2 , wherein the control system is configured to supply the electrical current to the electromagnet based on an operating state of a blower of the terminal unit. 
     
     
         6 . The terminal unit of  claim 5 , wherein the control system is configured to stop the electrical current from being supplied to the electromagnet during operation of the blower, such that the electromagnet is deactivated. 
     
     
         7 . The terminal unit of  claim 6 , wherein the control system is configured to supply the electrical current to the electromagnet when the blower stops operating, such that the electromagnet is activated. 
     
     
         8 . The terminal unit of  claim 1 , further comprising a blower positioned within the second chamber, the blower configured to selectively force the second air flow from the second chamber to the first chamber through the opening when the electromagnet is deactivated. 
     
     
         9 . The terminal unit of  claim 1 , wherein the electromagnet is coupled to the internal wall and the damper door is rotatably coupled to the internal wall. 
     
     
         10 . The terminal unit of  claim 1 , further comprising a damper collar coupled to the internal wall, wherein the damper door is rotatably coupled to the damper collar, and wherein the electromagnet is coupled to the damper collar. 
     
     
         11 . The terminal unit of  claim 1 , wherein at least a portion of the damper door is formed from a ferromagnetic material that is attracted by a magnetic force. 
     
     
         12 . The terminal unit of  claim 1 , further comprising a control system configured to activate the electromagnet to prevent the second air flow from mixing with the first air flow and to deactivate the electromagnet to allow the second air flow to mix with the first air flow to adjust a characteristic of the first air flow. 
     
     
         13 . A terminal unit for a heating, ventilation, and/or air conditioning (HVAC) system, comprising:
 a housing comprising a first chamber configured to receive a first air flow and a second chamber configured to receive a second air flow;   an internal wall disposed within the housing and extending between the first chamber and the second chamber, wherein the internal wall comprises an opening formed therein;   a damper door rotatably coupled to the internal wall, wherein the damper door is configured to occlude the opening in a closed position; and   an electromagnet coupled to the internal wall, wherein the electromagnet is configured to generate a magnetic field to retain the damper door toward the closed position.   
     
     
         14 . The terminal unit of  claim 13 , comprising a control system configured to regulate an electrical current supplied to the electromagnet. 
     
     
         15 . The terminal unit of  claim 14 , wherein the control system is configured to regulate the electrical current supplied to the electromagnet based on an operating state of a blower of the terminal unit. 
     
     
         16 . The terminal unit of  claim 15 , wherein the control system is configured to
 stop the electrical current from being supplied to the electromagnet to de-energize the electromagnet during operation of the blower, such that the second air flow driven by the blower may force the damper door from the closed position and move through the opening, and   supply the electrical current to the electromagnet to energize the electromagnet when the blower is not operating, such that the damper door is maintained in the closed position when the blower is not operating.   
     
     
         17 . A terminal unit for a heating, ventilation, and/or air conditioning (HVAC) system, comprising:
 a housing comprising a first chamber configured to receive a first air flow and a second chamber configured to receive a second air flow;   an internal wall disposed within the housing and extending between the first chamber and the second chamber, wherein the internal wall comprises an opening formed therein;   a damper collar coupled to the internal wall and disposed about the opening;   a damper door rotatably coupled to the damper collar, wherein the damper door is configured to abut the damper collar and occlude the opening in a closed position; and   an electromagnet coupled to the damper collar, wherein the electromagnet is configured to generate a magnetic field to draw the damper door toward the closed position.   
     
     
         18 . The terminal unit of  claim 17 , comprising a control system configured to regulate electrical current supplied to the electromagnet. 
     
     
         19 . The terminal unit of  claim 18 , wherein the control system is configured to regulate the electrical current supplied to the electromagnet based on an operating state of a blower of the terminal unit. 
     
     
         20 . The terminal unit of  claim 19 , wherein the control system is configured to
 stop the electrical current from being supplied to the electromagnet to de-energize the electromagnet during operation of the blower, such that the second air flow driven by the blower may force the damper door from the closed position and move through the opening, and   supply the electrical current to the electromagnet to energize the electromagnet when the blower is not operating, such that the damper door is maintained in the closed position when the blower is not operating.