Dynamic temperature compensation for thermostats

Abstract

A method and apparatus for automatically compensating ambient air temperature readings observed by a thermostat. Internal, active components of a thermostat are individually activated, based on an operating state of a thermostat. Each of the active components generates heat that interferes with ambient air temperature readings. A compensated ambient air temperature reading is calculated by knowing which active components are active during particular operating states of the thermostat and, in some cases, how long each active component has been active.

I claim: 
     
         1 . A method, performed by a thermostat, for automatically compensating ambient air temperature readings, comprising:
 determining an ambient air temperature;   determining an operating state of a heat-producing, internal component of the thermostat; and   adjusting the ambient air temperature based on the operating state of the internal component to produce a compensated ambient air temperature.   
     
     
         2 . The method of  claim 1 , wherein adjusting the ambient air temperature comprises:
 identifying a temperature offset associated with the operating state of the internal component; and   applying the temperature offset to the ambient air temperature to produce the compensated ambient air temperature.   
     
     
         3 . The method of  claim 2 , wherein identifying the temperature offset comprises:
 retrieving the temperature offset from a lookup table in association with the internal component and the operating state of the internal component.   
     
     
         4 . The method of  claim 1 , wherein adjusting the ambient air temperature comprises:
 periodically calculating the compensated ambient air temperature as a function of the internal component and an elapsed time after the operating state of the internal component has changed.   
     
     
         5 . The method of  claim 4 , wherein periodically calculating the compensated ambient air temperature comprises:
 determining a maximum temperature offset;   determining a current temperature offset based on the maximum temperature offset, the elapsed time and a previous temperature offset; and   applying the current temperature offset to the ambient air temperature to produce the compensated ambient air temperature.   
     
     
         6 . The method of  claim 4 , further comprising:
 determining a second operating state of a second heat-producing, internal component of the thermostat;   identifying a temperature offset associated with the operating state of the 2 nd  internal component; and   applying the temperature offset to the compensated ambient air temperature to produce a multi-compensated ambient air temperature.   
     
     
         7 . The method of  claim 1 , further comprising:
 determining a rate of change of the heat generated by the internal component; and   calculating the compensated ambient air temperature as a function of the rate of change of the heat generated by the internal component after the internal component has been activated.   
     
     
         8 . The method of  claim 7 , further comprising:
 determining a second rate of change of heat generated by a second heat-producing, internal component of the thermostat; and   calculating the compensated ambient air temperature as a function of the rate of change of the heat generated by the internal component and the second rate of change of heat generated by the second internal component.   
     
     
         9 . The method of  claim 1 , wherein determining an operating state of the heat-producing, internal component comprises:
 determining an operating state of the thermostat; and   determining that the heat-producing, internal component is in an active state during the operating state.   
     
     
         10 . The method of  claim 1 , further comprising:
 determining an operating state of the thermostat;   determining that the heat-producing, internal component is in an active state during the operating state;   determining that a second heat-producing, internal component of the thermostat is in an inactive state during the operating state; and   adjusting the ambient air temperature based on the heat-producing, internal component only.   
     
     
         11 . A thermostat, for automatically compensating ambient air temperature readings observed by the thermostat, comprising:
 a temperature sensor;   a heat-producing, internal component;   a memory for storing processor-executable instructions; and   a processor, coupled to the temperature sensor, the heat-producing, internal component in the memory, for executing the processor-executable instructions that cause the processor to:   determine an ambient air temperature;   determine an operating state of a heat-producing, internal component of the thermostat; and   adjust the ambient air temperature based on the operating state of the internal component to produce a compensated ambient air temperature.   
     
     
         12 . The thermostat of  claim 11 , wherein the processor-executable instructions for adjusting the ambient air temperature comprises instructions that cause the processor to:
 identify a temperature offset associated with the operating state of the internal component; and   apply the temperature offset to the ambient air temperature to produce the compensated ambient air temperature.   
     
     
         13 . The thermostat of  claim 12 , wherein the processor-executable instructions for identifying the temperature offset comprises instructions that cause the processor to:
 retrieve the temperature offset from a lookup table in association with the internal component and the operating state of the internal component.   
     
     
         14 . The thermostat of  claim 11 , wherein the processor-executable instructions for adjusting the ambient air temperature comprises instructions that cause the processor to:
 periodically calculate the compensated ambient air temperature as a function of the internal component and a time period after the operating state of the internal component has changed.   
     
     
         15 . The thermostat of  claim 14 , wherein the processor-executable instructions for periodically calculating the compensated ambient air temperature comprises:
 determine a maximum temperature offset;   determine a current temperature offset based on the maximum temperature offset, the elapsed time and a previous temperature offset; and   apply the current temperature offset to the ambient air temperature to produce the compensated ambient air temperature.   
     
     
         16 . The thermostat of  claim 14 , wherein the processor-executable instructions comprise further instructions that cause the processor to:
 determine a second operating state of a second heat-producing, internal component of the thermostat;   identify a temperature offset associated with the operating state of the 2 nd  internal component; and   apply the temperature offset to the compensated ambient air temperature to produce a multi-compensated ambient air temperature.   
     
     
         17 . The thermostat of  claim 11 , wherein the processor-executable instructions comprise further instructions that cause the processor to:
 determine a rate of change of the heat generated by the internal component; and   calculate the compensated ambient air temperature as a function of the rate of change of the heat generated by the internal component after the internal component has been activated.   
     
     
         18 . The thermostat of  claim 17 , wherein the processor-executable instructions comprise further instructions that cause the processor to:
 determine a second rate of change of heat generated by a second heat-producing, internal component of the thermostat; and   calculate the compensated ambient air temperature as a function of the rate of change of the heat generated by the internal component and the second rate of change of heat generated by the second internal component.   
     
     
         19 . The thermostat of  claim 11 , wherein the processor-executable instructions for determining an operating state of the heat-producing, internal component comprises instructions that cause the processor to:
 determine an operating state of the thermostat; and   determine that the heat-producing, internal component is in an active state during the operating state.   
     
     
         20 . The thermostat of  claim 11 , wherein the processor-executable instructions comprise further instructions that cause the processor to:
 determine an operating state of the thermostat;   determine that the heat-producing, internal component is in an active state during the operating state;   determine that a second heat-producing, internal component of the thermostat is in an inactive state during the operating state; and   adjust the ambient air temperature based on the heat-producing, internal component only.