Compact Freezer Unit

Abstract

A compact freezer unit for supplying conditioned air to the interior of a structure is provided herein. The compact freezer unit includes a housing containing one or more components of the freezer unit, the housing having dimensions of height, width, and depth. The components include an evaporator comprising one or more coils and an evaporator fan, a condenser and a condenser fan, a Direct Current (DC) Enhanced Vapor Injection (EVI) inverter compressor, an economizer for separating liquid and vapor refrigerant, a 4-way valve and a chassis belt electric heater configured to defrost one or more surfaces, one or more sensors for sensing a condition and generating an output signal received by a controller, and a plurality of refrigerant lines fluidly connecting the condenser and the evaporator.

What is claimed is: 
     
         1 . A compact freezer unit for supplying conditioned air to an interior of a structure, the compact freezer unit comprising:
 a housing containing one or more components of the freezer unit, the housing having dimensions of height, width, and depth, wherein at least two of the dimensions are less than 35 inches,   the components comprising:   an evaporator comprising one or more coils and an evaporator fan;   a condenser and a condenser fan;   a Direct Current (DC) Enhanced Vapor Injection (EVI) inverter compressor;   an economizer for separating liquid and vapor refrigerant;   a 4-way valve and a chassis belt electric heater configured to defrost one or more surfaces;   one or more sensors for sensing a condition and generating an output signal received by a controller;   a plurality of refrigerant lines fluidly connecting the condenser and the evaporator; and   wherein the unit is capable of producing conditioned air having a temperature of 10° F. or lower when the conditioned air exits the compact freezer unit.   
     
     
         2 . The compact freezer unit of  claim 1 , wherein the evaporator fan comprises a brushless direct current motor. 
     
     
         3 . The compact freezer unit of  claim 1 , wherein the condenser fan comprises a brushless direct current motor. 
     
     
         4 . The compact freezer unit of  claim 1 , wherein the unit is configured with a hybrid power supply that is compatible with at least a prime power supply and a 200 Vdc-370 Vdc auxiliary DC power supply. 
     
     
         5 . The compact freezer unit of  claim 1 , wherein the one or more sensors includes at least a defrost temperature sensor positioned about the evaporator. 
     
     
         6 . The compact freezer unit of  claim 5 , wherein the 4-way valve is configured to reverse a flow of a refrigerant in at least a portion of the plurality of refrigerant lines for defrosting a surface of the evaporator. 
     
     
         7 . The compact freezer unit of  claim 6 , wherein the controller is configured to receive an output signal of the defrost temperature sensor and direct a positioning of the 4-way valve between a cooling position and a defrost position, and wherein said controller is capable of switching the positioning of the 4-way valve at timed intervals. 
     
     
         8 . The compact freezer unit of  claim 4 , wherein the unit is capable of receiving power from the prime power supply or the auxiliary DC power supply individually, or both simultaneously, and the unit is configured to generate an alarm when the prime power supply is not providing power to the unit. 
     
     
         9 . The compact freezer unit of  claim 1 , wherein the unit further comprises an economizer. 
     
     
         10 . A compact freezer unit for supplying conditioned air to an interior of a structure, the compact freezer unit comprising:
 a housing containing one or more components of the freezer unit, the housing having dimensions of height, width, and depth, wherein at least two of the dimensions are less than 35 inches,   the components comprising:   an evaporator comprising one or more coils and an evaporator fan;   a condenser and a condenser fan;   a Direct Current (DC) Enhanced Vapor Injection (EVI) inverter compressor;   an economizer for separating liquid and vapor refrigerant;   a 4-way valve and a chassis belt electric heater configured to defrost one or more surfaces;   one or more sensors for sensing a condition and generating an output signal received by a controller;   a plurality of refrigerant lines fluidly connecting the condenser and the evaporator; and   a duct system for transferring air from the interior of the structure to the housing and back to the interior, wherein the duct system comprises a supply air duct and a return air duct,   wherein the unit is capable of producing conditioned air having a temperature of 10° F. or lower when the conditioned air exits the compact freezer unit.   
     
     
         11 . The compact freezer of  claim 10 , wherein the evaporator fan comprises a high head pressure for moving air through at least a portion of the duct system. 
     
     
         12 . The compact freezer unit of  claim 11 , wherein the evaporator fan comprises a brushless direct current motor and wherein the condenser fan comprises a brushless direct current motor. 
     
     
         13 . The compact freezer unit of  claim 10 , wherein the unit is configured with a hybrid power supply that is compatible with at least a prime power supply and a 200 Vdc-370 Vdc auxiliary DC power supply. 
     
     
         14 . The compact freezer unit of  claim 10 , wherein the one or more sensors includes at least a defrost temperature sensor positioned about the evaporator. 
     
     
         15 . The compact freezer unit of  claim 14 , wherein the 4-way valve is configured to reverse a flow of a refrigerant in at least a portion of the plurality of refrigerant lines for defrosting a surface of the evaporator. 
     
     
         16 . The compact freezer unit of  claim 15 , wherein the controller is configured to receive an output signal of the defrost temperature sensor and direct a positioning of the 4-way valve between a cooling position and a defrost position, and wherein said controller is capable of switching the positioning of the 4-way valve at timed intervals. 
     
     
         17 . The compact freezer unit of  claim 13 , wherein the unit is capable of receiving power from the prime power supply or the auxiliary DC power supply individually, or both simultaneously, and the unit is configured to generate an alarm when the prime power supply is not providing power to the unit. 
     
     
         18 . The compact freezer unit of  claim 10 , wherein the unit further comprises an economizer. 
     
     
         19 . The compact freezer unit of  claim 10 , wherein the evaporator fan comprises a centrifugal fan capable of overcoming system resistance up to 50 Pa. 
     
     
         20 . The compact freezer unit of  claim 10 , wherein the unit is capable of supplying conditioned air at a temperature at or below −10° C.