Electric Heat Defrost Alogrithm

Abstract

A method of operating an HVAC system is provided. The method comprises, when a defrost mode of the HVAC system ends and a defrost recovery mode of the HVAC system begins, continuing to operate a supplemental heat generator that was in operation in the defrost mode. The method further comprises, after a period of time in the defrost recovery mode has passed, deactivating at least a first portion of the total heating capacity of the supplemental heat generator.

What is claimed: 
     
         1 . A method of operating an HVAC system, comprising:
 when a defrost mode of the HVAC system ends and a defrost recovery mode of the HVAC system begins, continuing to operate a supplemental heat generator that was in operation in the defrost mode; and   after a period of time in the defrost recovery mode has passed, deactivating at least a first portion of the total heating capacity of the supplemental heat generator.   
     
     
         2 . The method of  claim 1 , further comprising, when the supplemental heat generator has a plurality of portions of total heating capacity, after an additional period of time in the defrost recovery mode has passed, deactivating at least one additional portion of the total heating capacity of the supplemental heat generator, the deactivations of the portions continuing until the total heating capacity of the supplemental heat generator is deactivated. 
     
     
         3 . The method of  claim 1 , wherein the HVAC system provides a plurality of options for operation of the supplemental heat generator, the plurality of options including:
 at least a first option that provides relatively warmer discharge air in the defrost mode and the defrost recovery mode and uses a relatively greater amount of energy; and   at least a second option that provides relatively cooler discharge air in the defrost mode and the defrost recovery mode and uses a relatively smaller amount of energy,   wherein the discharge air temperature and the energy usage are at least partially controlled by activation and deactivation of the supplemental heat generator.   
     
     
         4 . The method of  claim 3 , wherein the plurality of options for operation of the supplemental heat generator further includes an option wherein operation of the supplemental heat generator ceases when the defrost mode ends. 
     
     
         5 . The method of  claim 4 , wherein the plurality of options for operation of the supplemental heat generator further includes an option wherein the supplemental heat generator is not operated. 
     
     
         6 . The method of  claim 3 , wherein the HVAC system includes a control mechanism that displays the plurality of options for operation of the supplemental heat generator and allows one of the plurality of options to be selected. 
     
     
         7 . The method of  claim 1 , wherein, when the supplemental heat generator is activated in the defrost mode, less than the total heating capacity of the supplemental heat generator is activated, and wherein at least one additional portion of the total heating capacity of the supplemental heat generator is activated at a later time, the activations of the portions continuing until the total heating capacity of the supplemental heat generator is activated or until a desired discharge air temperature is reached. 
     
     
         8 . An HVAC system, comprising:
 a supplemental heat generator configured such that, when a defrost mode of the HVAC system ends and a defrost recovery mode of the HVAC system begins, the supplemental heat generator continues operation that began in the defrost mode, and further configured such that, after a period of time in the defrost recovery mode has passed, at least a first portion of the total heating capacity of the supplemental heat generator is deactivated.   
     
     
         9 . The HVAC system of  claim 8 , wherein the supplemental heat generator is further configured such that, when the supplemental heat generator has a plurality of portions of total heating capacity, after an additional period of time in the defrost recovery mode has passed, at least one additional portion of the total heating capacity of the supplemental heat generator is deactivated, the deactivations of the portions continuing until the total heating capacity of the supplemental heat generator is deactivated. 
     
     
         10 . The HVAC system of  claim 8 , wherein the HVAC system provides a plurality of options for operation of the supplemental heat generator, the plurality of options including:
 at least a first option that provides relatively warmer discharge air in the defrost mode and the defrost recovery mode and uses a relatively greater amount of energy; and   at least a second option that provides relatively cooler discharge air in the defrost mode and the defrost recovery mode and uses a relatively smaller amount of energy,   wherein the discharge air temperature and the energy usage are at least partially controlled by activation and deactivation of the supplemental heat generator.   
     
     
         11 . The HVAC system of  claim 10 , wherein the plurality of options for operation of the supplemental heat generator further includes an option wherein operation of the supplemental heat generator ceases when the defrost mode ends. 
     
     
         12 . The HVAC system of  claim 11 , wherein the plurality of options for operation of the supplemental heat generator further includes an option wherein the supplemental heat generator is not operated. 
     
     
         13 . The HVAC system of  claim 10 , wherein the HVAC system includes a control mechanism that displays the plurality of options for operation of the supplemental heat generator and allows one of the plurality of options to be selected. 
     
     
         14 . The HVAC system of  claim 8 , wherein, when the supplemental heat generator is activated in the defrost mode, less than the total heating capacity of the supplemental heat generator is activated, and wherein at least one additional portion of the total heating capacity of the supplemental heat generator is activated at a later time, the activations of the portions continuing until the total heating capacity of the supplemental heat generator is activated or until a desired discharge air temperature is reached. 
     
     
         15 . A method of operating an HVAC system, comprising:
 when a supplemental heat generator in the HVAC system is activated in a defrost mode of the HVAC system, activating less than the total heating capacity of the supplemental heat generator; and   when the defrost mode of the HVAC system ends and a defrost recovery mode of the HVAC system begins, continuing to operate the supplemental heat generator.   
     
     
         16 . The method of  claim 15 , wherein at least one additional portion of the total heating capacity of the supplemental heat generator is activated at a later time in the defrost mode, the activations of the portions continuing until the total heating capacity of the supplemental heat generator is activated or until a desired discharge air temperature is reached. 
     
     
         17 . The method of  claim 15 , wherein, after a period of time in the defrost recovery mode has passed, a first portion of the total heating capacity of the supplemental heat generator is deactivated, and wherein, after an additional period of time in the defrost recovery mode has passed, at least one additional portion of the total heating capacity of the supplemental heat generator is deactivated, the deactivations of the portions continuing until the total heating capacity of the supplemental heat generator is deactivated. 
     
     
         18 . The method of  claim 15 , wherein the HVAC system provides a plurality of options for operation of the supplemental heat generator, the plurality of options including:
 at least a first option that provides relatively warmer discharge air in the defrost mode and the defrost recovery mode and uses a relatively greater amount of energy; and   at least a second option that provides relatively cooler discharge air in the defrost mode and the defrost recovery mode and uses a relatively smaller amount of energy,   wherein the discharge air temperature and the energy usage are at least partially controlled by activation and deactivation of the supplemental heat generator.   
     
     
         19 . The method of  claim 18 , wherein the plurality of options for operation of the supplemental heat generator further includes an option wherein operation of the supplemental heat generator ceases when the defrost mode ends and an option wherein the supplemental heat generator is not operated. 
     
     
         20 . The method of  claim 18 , wherein the HVAC system includes a control mechanism that displays the plurality of options for operation of the supplemental heat generator and allows one of the plurality of options to be selected.