Method, System and Temperature Control of a Heating, Ventilation and Air Conditioning Unit

Abstract

A control assembly for controlling an HVAC unit, and method of controlling an HVAC unit, the HVAC unit having a burner assembly and at least one of a blower, an inducer fan, an air/fuel control system, the method including: measuring a temperature of the burner assembly; comparing the measured temperature of the burner assembly with a predetermined temperature based on firing rate; controlling the HVAC unit to cause the temperature of the burner assembly to come within predetermined limits; wherein the controlling step includes at least one of the steps of: initiating, terminating or modifying, the operation of one or more of the blower, the inducer fan, or modifying an air/fuel mixture of the air/fuel control system, reducing the temperature of the burner assembly to within predetermined limits.

We claim: 
     
         1 . A control assembly for controlling an HVAC unit, comprising:
 a temperature sensing device capable of measuring at least one of a surface temperature or an internal temperature of a burner assembly of an HVAC unit and providing a signal corresponding to the measured temperature;   a control device operatively connected to the temperature sensing device, the control device configured to:   receive the signals from the temperature sensing device;   compare the measured temperature to at least one predetermined temperature, and operate in a plurality of operational modes based at least in part on the difference between the measured temperature and the at least one predetermined temperature.   
     
     
         2 . The control assembly according to  claim 1  operable in a first operational mode to send at least one signal to operate at full capacity at least one of a blower, an inducer fan or an air/fuel control system. 
     
     
         3 . The control assembly according to  claim 1  operable in a second operational mode to send at least one signal to operate at less than full capacity at least one of the blower, the inducer fan or the air/fuel control system. 
     
     
         4 . The control assembly according to  claim 1  operable in a third operational mode to send at least one signal to operate at a variable capacity or rate, at least one of the blower, the inducer fan or the air/fuel control system. 
     
     
         5 . The control assembly according to  claim 1  operable in a fourth operational mode to send at least one signal to operate at varying time intervals at least one of the blower, the inducer fan or the air/fuel control system. 
     
     
         6 . The control assembly according to  claim 1  operable in a fifth operational mode to send at least one signal to prohibit the operation for a predetermined interval at least one of the blower, the inducer fan or the air/fuel control system. 
     
     
         7 . The control assembly according to  claim 1  wherein one or more sensors are operably coupled to at least one of a burner box, the one or more components of the burner assembly, the one or more components of the air/fuel control system. 
     
     
         8 . The control assembly according to  claim 1  wherein one or more sensors are thermistors. 
     
     
         9 . A method of controlling an HVAC unit, the HVAC unit having a burner assembly and at least one of a blower, an inducer fan, an air/fuel control system, the method comprising:
 measuring a temperature of the burner assembly;   comparing the measured temperature of the burner assembly with a predetermined temperature based on firing rate;   controlling the HVAC unit to cause the temperature of the burner assembly to come within predetermined limits;   wherein the controlling step includes at least one of the steps of: initiating, terminating or modifying, the operation of one or more of the blower, the inducer fan, or modifying the air/fuel mixture of the air/fuel control system, reducing the temperature of the burner assembly to within predetermined limits.   
     
     
         10 . The method according to  claim 9  wherein the controlling step includes measuring at least one of a surface temperature, or an internal temperature, of the burner assembly. 
     
     
         11 . The method according to  claim 9  wherein the controlling step further includes the steps of:
 setting at least one desired temperature; 
 setting at least one predetermined temperature and choosing at least one predetermined temperature limit. 
 
     
     
         12 . The method according to  claim 9  wherein the controlling step further includes the steps of: determining safe operation of the HVAC unit based on one or more of: pulse-width modulation duty cycles, revolutions per minute (RPMs) increases over steady-state RPMs, predetermined temperature limits. 
     
     
         13 . The method according to  claim 9  wherein the controlling step further includes the steps of: using temperature data based on a steady-state temperature of the burner assembly wherein an operating temperature range at the steady-state is determined for each firing rate. 
     
     
         14 . The method according to  claim 9  wherein the controlling step further includes the steps of: determining temperatures at various air/fuel mixture conditions. 
     
     
         15 . A system for controlling the temperature of an HVAC unit comprising:
 an HVAC unit having a burner assembly;   at least one of a blower, an inducer fan or an air/fuel control system;   a temperature sensing device operably coupled to the burner assembly;   a control device in communication with the temperature sensing device, the control device configured to:
 receive at least one signal from the temperature sensing device, the at least one signal indicative of the burner assembly temperature; 
 compare the at least one signal indicative of the burner assembly temperature to a predetermined temperature; 
 transmit a signal to operate the HVAC unit in at least one operational mode when the temperature of the burner assembly exceeds the predetermined temperature limit. 
   
     
     
         16 . The system according to  claim 15  wherein the control device is further configured to operate in a first operational mode to send at least one signal to operate at full capacity at least one of the blower, the inducer fan or the air/fuel control system. 
     
     
         17 . The system according to  claim 15  wherein the control device is further configured to operate in a second operational mode to send at least one signal to operate at less than full capacity, at least one of the blower, the inducer fan or the air/fuel control system. 
     
     
         18 . The system according to  claim 15  wherein the control device is further configured to operate in a third operational mode to send at least one signal to operate at a variable capacity or rate at least one of the blower, the inducer fan or the air/fuel control system. 
     
     
         19 . The system according to  claim 15  wherein the control device is further operative in a fourth operational mode to send at least one signal to operate at varying time intervals at least one of the blower, the inducer fan or the air/fuel control system. 
     
     
         20 . The system according to  claim 15  wherein the control device is further operative in a fifth operational mode to prohibit the operation for a predetermined time interval at least one of the blower, the inducer fan or the air/fuel control system.