Communicating thermostat recovery algorithm

Abstract

The present subject matter relates methods and systems for operation of an HVAC system including a heat pump and a secondary energy source (electric or gas) where a utility's demand response server may issue demand response event instructions. Upon receipt of a demand response event instruction as set point for controlling the HVAC system may be changed and, upon expiration of the demand response event, the HVAC system is controlled so that operation of its secondary energy source is inhibited until recovery of the system to its user established set point is obtained.

What is claimed is: 
     
         1 . A method for managing energy usage in an HVAC system comprising a heat pump and a secondary energy source, comprising:
 monitoring the HVAC system for a change in temperature set point;   determining whether a detected change in temperature set point is due to a demand response event; and   inhibiting operation of the secondary energy source if the temperature set point are due to a demand response event.   
     
     
         2 . A method as in  claim 1 , further comprising:
 delaying operation the heat pump until the demand response event has expired.   
     
     
         3 . A method as in  claim 1 , further comprising:
 determining whether a detected change in temperature set point is due to a user change;   selecting whether to operate the system using only the heat pump; and   allowing operation of the secondary energy source if a selection is made to not operate using only the heat pump.   
     
     
         4 . A method as in  claim 1 , wherein monitoring for a change in temperature set point is conducted by a thermostat. 
     
     
         5 . A method as in  claim 4 , wherein the steps of determining and inhibiting are performed within the thermostat. 
     
     
         6 . A method as in  claim 4 , wherein the steps of determining and inhibiting are performed within a home energy management device. 
     
     
         7 . The method of  claim 1 , wherein the secondary energy source corresponds to at least one of an electric and gas energy source. 
     
     
         8 . An energy management system, comprising:
 a central facility comprising a demand response server;   an HVAC system comprising a heat pump and a secondary energy source;   a thermostat configured to control operation of said HVAC system; and   a communications system coupling said thermostat and said demand response server for communications there between,   wherein said demand response server is configured to transmit instructions to said thermostat to change its set point, and wherein said HVAC system is inhibited from operating its secondary energy source following receipt of thermostat change instructions from said demand response server.   
     
     
         9 . A system as in  claim 8 , wherein said thermostat is configured to inhibit operation of said secondary energy source. 
     
     
         10 . A system as in  claim 9 , wherein the transmitted instructions correspond to a demand response event and said thermostat is configured to inhibit operation of said HVAC system until said demand response event has expired. 
     
     
         11 . A system as in  claim 8 , further comprising:
 a home energy management device,   wherein said home energy management device is configured to inhibit operation of said secondary energy source.   
     
     
         12 . A system as in  claim 11 , wherein the transmitted instructions correspond to a demand response event and said home energy management device is configured to inhibit operation of said HVAC system until said demand response event has expired. 
     
     
         13 . A system as in  claim 8 , wherein said secondary energy source corresponds to at least one of an electric and gas energy source.