Air-conditioning with dehumidification

Abstract

One embodiment comprises an apparatus with an evaporative unit for a refrigerant having a flow direction opposing the airflow direction and an adjustable airflow rate to utilize to produce both cold/dehumidified exit air and warmed exit refrigerant for high efficiency and to maintain an airflow sufficient to avoid freeze-up of evaporative unit or freeze-up to an extent that blocks the airflow. This may produce low humidity even when the room thermostat is set warm (e.g. 85F) and 5%-30% lower A/C bills. Other embodiments comprise systems and methods related to the adjustable airflow. A further embodiment comprises a controller to adjust the humidity in an air-conditioned space to produce air, which is both temperature and humidity controlled.

1 . An evaporative unit with a top, a bottom, a right side, a left side, a front, and a back, wherein air flows from the back of the evaporative unit to the front of the evaporative unit between the right side and the left side of the evaporative unit, the evaporative unit comprising:
 a first row comprising a first set of tubes with projections to conduct heat from air flowing through the first row into refrigerant flowing through the first set of tubes, wherein each tube of the first set of tubes comprises a first end and a second end, wherein refrigerant flows from the first end to the second end of each tube of the first set of tubes and the first set of tubes direct refrigerant in the evaporative unit within the first row;   a second row comprising a second set of tubes with projections to conduct heat from air flowing through the second row into the refrigerant flowing through the second set of tubes, wherein each tube of the second set of tubes comprises a first end and a second end, wherein refrigerant flows from the first end to the second end of each tube in the second set of tubes and the second set of tubes direct refrigerant in the evaporative unit within the second row; and   row interconnect lines coupled with the first row and the second row to connect the sets of tubes of the rows in series to direct the refrigerant from the front of the evaporative unit toward the back of the evaporative unit through the rows in series.   
     
     
         2 . The evaporative unit of  claim 1 , further comprising additional rows coupled in series with the first row and the second row between the front and the back of the evaporative unit. 
     
     
         3 . The evaporative unit of  claim 1 , wherein the evaporative unit comprises six rows, wherein the first row is a front row at the front of the evaporative unit and the first row directs refrigerant through the first set of tubes from the right side to the left side and a back row at the back of the evaporative unit directs refrigerant from the left side to the right side. 
     
     
         4 . The evaporative unit of  claim 1 , wherein the evaporative unit comprises six rows, wherein the first row is a front row at the front of the evaporative unit and the first row directs refrigerant through the first set of tubes from the left side to the right side of the evaporative unit and a back row at the back of the evaporative unit directs refrigerant from the right side to the left side. 
     
     
         5 . The evaporative unit of  claim 1 , wherein the evaporative unit further comprises a front row at the front of the evaporative unit and a back row at the back of the evaporative unit, wherein a first end of at least two of the tubes in the front row couples with lines to receive refrigerant from an expansion valve. 
     
     
         6 . The evaporative unit of  claim 5 , wherein a second end of at least two of the tubes in the back row couples with a return line to return the refrigerant to a compressor. 
     
     
         7 . An air-handling unit, comprising:
 a cabinet to receive an incoming air flow and to output a conditioned, outgoing air flow, the cabinet comprising:
 an evaporative unit comprising at least a front row at a front of the evaporative unit and a back row at a back of the evaporative unit to direct refrigerant from tubes in the front row through tubes in the back row in series, wherein the air-handling unit directs the incoming air flow through the back row and the front row in series from the back of the evaporative unit to the front of the evaporative unit; 
 a return line coupled with the back row of the evaporative unit to return the refrigerant to a compressor; and 
 a fan to force air flow through the evaporative unit from the back through the front of the evaporative unit. 
   
     
     
         8 . The air-handling unit of  claim 7 , further comprising an expansion valve to reduce pressure of the refrigerant prior to the refrigerant entering the tubes of the front row. 
     
     
         9 . The air-handling unit of  claim 7 , further comprising a distributor to distribute the refrigerant to tubes of the front row. 
     
     
         10 . The air-handling unit of  claim 7 , further comprising a temperature sensor to change states in response to a temperature of the refrigerant rising above and in response to the temperature falling below a temperature range. 
     
     
         11 . The air-handling unit of  claim 10 , further comprising a fan controller coupled with the fan to change the speed of the fan in response to a state of the temperature sensor. 
     
     
         12 . The air-handling unit of  claim 7 , further comprising a heater to heat the outgoing air flow from the cabinet to adjust a temperature of the outgoing air flow. 
     
     
         13 . A package unit, comprising:
 at least one cabinet to receive an incoming air flow and to output a conditioned, outgoing air flow, the at least one cabinet comprising:
 an evaporative unit comprising at least a front row at a front of the evaporative unit and a back row at a back of the evaporative unit to direct refrigerant from tubes in the front row through tubes in the back row in series, wherein the air-handling unit directs the incoming air flow through the back row and the front row in series from the back of the evaporative unit to the front of the evaporative unit; 
 a return line coupled with the back row of the evaporative unit to return the refrigerant to a compressor; 
 a compressor coupled with the return line to receive the refrigerant from the evaporative unit; 
 a condenser coil coupled with the compressor to receive the refrigerant from the compressor; 
 at least one fan to force air flow through the evaporative unit from the back through the front of the evaporative unit and to force air flow through a condenser coil; and 
 a fan controller to adjust a speed of the fan to adjust the speed of the air flow through the evaporative unit. 
   
     
     
         14 . The package unit of  claim 13 , further comprising a temperature sensor coupled with the return line to determine when the temperature of the refrigerant rises above and falls below a temperature range. 
     
     
         15 . The package unit of  claim 13 , further comprising a damper to adjust the outgoing air flow from the cabinet. 
     
     
         16 . The package unit of  claim 13 , wherein the at least one fan comprises a first fan to force air flow through the evaporative unit and a second fan to force air flow through the condenser coil. 
     
     
         17 . The package unit of  claim 13 , wherein the at least one fan comprises a fan motor coupled with a fan blade within a first compartment of the cabinet to force the air flow through the evaporative unit, wherein the fan motor is also coupled with a second fan blade in a second compartment of the cabinet to force air flow through the condenser coil. 
     
     
         18 . The package unit of  claim 17 , wherein the fan motor resides in the second compartment of the cabinet. 
     
     
         19 . A method comprising:
 directing an incoming air flow through an evaporative unit comprising at least a front row and a back row, wherein the air flows from through the back row prior to flowing through the front row, to generate an exiting air flow after passing through the front row;   receiving a refrigerant from a condenser;   distributing the refrigerant in parallel into tubes of the front row of the evaporative unit;   directing the refrigerant through the tubes of the front row in a direction substantially perpendicular to a direction of the air flowing through the evaporative unit;   capturing heat by the refrigerant from the air flowing through the front row via conduction of heat through the tubes and projections coupled with the tubes;   directing the refrigerant into tubes of the back row of the evaporative unit;   directing the refrigerant through the tubes of the back row in a direction substantially perpendicular to a direction of the air flowing through the evaporative unit;   capturing heat by the refrigerant from the air flowing through the back row via conduction of heat through the tubes and projections coupled with the tubes; and   directing the refrigerant into a return line to return the refrigerant to a compressor.   
     
     
         20 . The method of  claim 19 , further comprising reducing the pressure of the refrigerant received from the condenser via an expansion valve prior to distributing the refrigerant. 
     
     
         21 . The method of  claim 19 , further comprising detecting, by a temperature sensor, a temperature of the refrigerant in the return line. 
     
     
         22 . The method of  claim 21 , further comprising changing a speed of a two-speed fan to change a speed of an outgoing air flow from an air-handling unit in response to detecting the temperature. 
     
     
         23 . The method of  claim 21 , wherein detecting, by the temperature sensor, the temperature comprises opening or closing an electrical circuit with a bimetal switch in response to a change in the temperature of the refrigerant passed a threshold temperature. 
     
     
         24 . The method of  claim 19 , wherein directing the incoming air flow comprises directing the incoming air flow through at least one row between the front row and the back row, wherein the refrigerant flows through tubes of the at least one row to capture heat from the air flow. 
     
     
         25 . The method of  claim 19 , wherein distributing the refrigerant comprises regulating the pressure of the refrigerant in parallel lines distributing the refrigerant.