Airflow management system in a hvac unit including two fans of different diameters

Abstract

Air is heated by a gas or electric heat exchanger or cooled in an evaporator coil. The air is discharged through a discharge opening to heat or cool an area. Two fans draw an exterior air stream over the gas or electric heat exchanger or the evaporator coil. A first fan has a diameter greater than a diameter of a second fan. When in a side discharge configuration, the second fan is located between the first fan and the side discharge opening. The first fan has a larger diameter to produce a stronger airflow to overcome the airflow produced by the second fan, better distributing the airflow from the first fan. The airflow generated by the second fan is directed to the discharge opening relatively unimpeded.

1 - 20 . (canceled) 
   
   
       21 . A heat exchanger comprising:
 a heat exchanger coil;   a first fan to produce a first airflow that exchanges heat with a medium in the heat exchanger coil; and   a second fan to produce a second airflow that exchanges heat with the medium in the heat exchanger coil, wherein the first airflow is stronger than the second airflow, and the first airflow and the second airflow flow through a common discharge.   
   
   
       22 . The heat exchanger as recited in  claim 21  wherein the first fan has a first diameter and the second fan has a second diameter, and the first diameter is greater than the second diameter. 
   
   
       23 . The heat exchanger as recited in  claim 21  wherein the first fan operates at a first fan speed and the second fan operates at a second fan speed, and the first fan speed is greater than the second fan speed. 
   
   
       24 . The heat exchanger as recited in  claim 21  wherein the first airflow and the second airflow exit through the common discharge, and the first airflow and the second airflow are directed along a substantially straight path from the first fan and the second fan, respectively, to the common discharge. 
   
   
       25 . The heat exchanger as recited in  claim 21  wherein the first airflow and the second airflow exit through the common discharge and the second fan is located between the first fan and the common discharge. 
   
   
       26 . The heat exchanger as recited in  claim 21  wherein the first fan and the second fan operate in parallel. 
   
   
       27 . The heat exchanger as recited in  claim 21  wherein the heat exchanger coil is an evaporator coil, and the first fan and the second fan draw the first airflow and the second airflow, respectively, over the evaporator coil. 
   
   
       28 . The heat exchanger as recited in  claim 21  wherein the heat exchanger is a gas or electric heat exchanger, and the first fan and the second fan blow the first airflow and the second airflow, respectively, over the gas or electric heat exchanger. 
   
   
       29 . An airflow management system comprising:
 a vapor compression system including an evaporator coil, wherein refrigerant flows through the evaporator coil;   a heating heat exchanger that produces a heated medium; and   an air moving section including:
 a first fan to produce a first airflow that exchanges heat with the refrigerant in the evaporator coil when the airflow management system is operating in a cooling mode and that exchanges heat with the heated medium in the heating heat exchanger when the airflow management system is operating in a heating mode, and 
 a second fan to produce a second airflow that exchanges heat with the refrigerant in the evaporator coil when the airflow management system is operating in the cooling mode and that exchanges heat with the heated medium in the heating heat exchanger when the airflow management system is operating in the heating mode, wherein the first airflow is stronger than the second airflow, and the first airflow and the second airflow flow through a common discharge. 
   
   
   
       30 . The system as recited in  claim 29  wherein the vapor compression system includes:
 a compressor to compress the refrigerant to a high pressure,   a condenser for exchanging heat between the refrigerant and a fluid, and   an expansion device to expand the refrigerant to a low pressure.   
   
   
       31 . The system as recited in  claim 29  wherein the first fan has a first diameter and the second fan has a second diameter, and the first diameter is greater than the second diameter. 
   
   
       32 . The system as recited in  claim 29  wherein the first fan operates at a first fan speed and the second fan operates at a second fan speed, and the first fan speed is greater than the second fan speed. 
   
   
       33 . The system as recited in  claim 29  wherein the first airflow and the second airflow exit the airflow management system through the common discharge, and the first airflow and the second airflow are directed along a substantially straight path from the first fan and the second fan, respectively, to the common discharge. 
   
   
       34 . The system as recited in  claim 29  wherein the first airflow and the second airflow exit the airflow management system through the common discharge and the second fan is located between the first fan and the common discharge. 
   
   
       35 . The system as recited in  claim 29  wherein the first fan and the second fan operate in parallel. 
   
   
       36 . The system as recited in  claim 29  wherein the first fan and the second fan draw the first airflow and the second airflow, respectively, over the evaporator coil. 
   
   
       37 . The system as recited in  claim 29  wherein the first fan and the second fan blow the first airflow and the second airflow, respectively, over the heating heat exchanger. 
   
   
       38 . A method of managing an airflow comprising the steps of: operating an airflow management system in one of a cooling mode and a heating mode;
 generating a first airflow that exchanges heat with a refrigerant in an evaporator coil when the airflow management system is operating in the cooling mode and that exchanges heat with a heated medium in a heating heat exchanger when the airflow management system is operating in the heating mode; and   generating a second airflow that exchanges heat with the refrigerant in the evaporator coil when the airflow management system is operating in the cooling mode and that exchanges heat with the heated medium in the heating heat exchanger when the airflow management system is operating in the heating mode, wherein the first airflow is stronger than the second airflow, and the first airflow and the second airflow flow through a common discharge.   
   
   
       39 . The method as recited in  claim 38  wherein the first airflow is generated by a first fan having a first diameter and the second airflow is generated by a second fan having a second diameter, wherein the first diameter is greater than the second diameter. 
   
   
       40 . The method as recited in  claim 38  wherein the first airflow has a first speed and the second airflow has a second speed, and the first speed is greater than the second speed.