In-wall dehumidifier control system

1. A dehumidifier, comprising:

a cabinet;

an air diffuser configured to diffuse an airflow from the dehumidifier, the air diffuser comprising an inlet, an outlet above the inlet, and a divider between the inlet and outlet, the divider configured to prevent the airflow entering the cabinet through the inlet from mixing with the airflow exiting the cabinet from the outlet;

a compressor;

an evaporator installed within the cabinet above the compressor, the evaporator comprising a plurality of evaporator coils;

a condenser installed within the cabinet above the evaporator, the condenser comprising a plurality of microchannel condenser coils;

a fan installed between the evaporator and a back surface of the cabinet, the fan configured to generate the airflow that flows into the cabinet through the inlet of the air diffuser and out of the cabinet through the outlet of the air diffuser, the airflow flowing through the evaporator and condenser in order to provide dehumidification to the airflow;

a drain pan installed within the cabinet below the evaporator, the drain pan configured to capture water removed from the airflow by the evaporator;

a sensor installed below the drain pan, the sensor configured to sense one or more environmental conditions of a bypass portion of the airflow; and

a processor configured to:

determine a first evaporator coil temperature set point and a second evaporator coil temperature set point, wherein the first evaporator coil temperature set point is lower than the second evaporator coil temperature set point;

determine whether the dehumidifier has been operating in a dehumidifying mode for a time period less than a predetermined amount of time;

in response to determining that the dehumidifier has been operating in the dehumidifying mode for a time period less than the predetermined amount of time, compare a first measured evaporator coil temperature to the first evaporator coil temperature set point;

in response to determining that the first measured evaporator coil temperature is less than the first evaporator coil temperature set point, set the dehumidifier to a defrost mode;

in response to determining that the dehumidifier has been operating in the dehumidifying mode for a time period equal to or greater than the predetermined amount of time, determine whether a second measured evaporator coil temperature is less than the second evaporator coil temperature set point; and

in response to determining that the second measured evaporator coil temperature is less than the second evaporator coil temperature set point, set the dehumidifier to the defrost mode.

2. The dehumidifier of claim 1 , wherein the processor is further configured to:

in response to determining that the first measured evaporator coil temperature is equal to or greater than the first evaporator coil temperature set point, determine whether the dehumidifier has been operating in the dehumidifying mode for a time period less than the predetermined amount of time.

3. The dehumidifier of claim 1 , wherein the fan and the compressor are enabled when the dehumidifier operates in the dehumidifying mode.

4. The dehumidifier of claim 1 , wherein the fan is enabled and the compressor is disabled when the dehumidifier operates in the defrost mode.

5. The dehumidifier of claim 1 , wherein the processor is further configured to:

determine whether a measured relative humidity is greater than a predetermined relative humidity set point;

in response to determining that the measured relative humidity is greater than the predetermined relative humidity set point, set the dehumidifier to the dehumidifying mode.

6. The dehumidifier of claim 5 , wherein the processor is further configured to:

in response to determining that the measured relative humidity is equal to or less than the predetermined relative humidity set point, set the dehumidifier to a dehumidistat mode.

7. The dehumidifier of claim 6 , wherein the fan and the compressor are disabled when the dehumidifier operates in the dehumidistat mode.

8. A dehumidifier, comprising:

an evaporator;

a condenser;

a fan configured to generate an airflow that flows through the evaporator and condenser in order to provide dehumidification to the airflow;

a compressor; and

a processor configured to:

determine a first evaporator coil temperature set point and a second evaporator coil temperature set point, wherein the first evaporator coil temperature set point is lower than the second evaporator coil temperature set point;

determine whether the dehumidifier has been operating in a dehumidifying mode for a time period less than a predetermined amount of time;

in response to determining that the dehumidifier has been operating in the dehumidifying mode for a time period less than the predetermined amount of time, compare a first measured evaporator coil temperature to the first evaporator coil temperature set point;

in response to determining that the first measured evaporator coil temperature is less than the first evaporator coil temperature set point, set the dehumidifier to a defrost mode;

in response to determining that the dehumidifier has been operating in the dehumidifying mode for a time period equal to or greater than the predetermined amount of time, determine whether a second measured evaporator coil temperature is less than the second evaporator coil temperature set point; and

in response to determining that the second measured evaporator coil temperature is less than the second evaporator coil temperature set point, set the dehumidifier to the defrost mode.

9. The dehumidifier of claim 8 , wherein the processor is further configured to:

in response to determining that the first measured evaporator coil temperature is equal to or greater than the first evaporator coil temperature set point, determine whether the dehumidifier has been operating in the dehumidifying mode for a time period less than the predetermined amount of time.

10. The dehumidifier of claim 8 , wherein the fan and the compressor are enabled when the dehumidifier operates in the dehumidifying mode.

11. The dehumidifier of claim 8 , wherein the fan is enabled and the compressor is disabled when the dehumidifier operates in the defrost mode.

12. The dehumidifier of claim 8 , wherein the processor is further configured to:

determine whether a measured relative humidity is greater than a predetermined relative humidity set point;

in response to determining that the measured relative humidity is greater than the predetermined relative humidity set point, set the dehumidifier to the dehumidifying mode.

13. The dehumidifier of claim 12 , wherein the processor is further configured to:

in response to determining that the measured relative humidity is equal to or less than the predetermined relative humidity set point, set the dehumidifier to a dehumidistat mode.

14. The dehumidifier of claim 13 , wherein the fan and the compressor are disabled when the dehumidifier operates in the dehumidistat mode.

15. A method, comprising:

determining a first evaporator coil temperature set point and a second evaporator coil temperature set point, the first evaporator coil temperature set point being lower than the second evaporator coil temperature set point;

determining that a dehumidifier has been operating in a dehumidifying mode for a time period less than a predetermined amount of time;

in response to determining that the dehumidifier has been operating in the dehumidifying mode for a time period less than the predetermined amount of time, determining that a first measured evaporator coil temperature is less than the first evaporator coil temperature set point; and

in response to determining that the first measured evaporator coil temperature is less than the first evaporator coil temperature set point, setting the dehumidifier to a defrost mode.

16. The method of claim 15 , wherein a fan and a compressor are enabled when the dehumidifier operates in the dehumidifying mode.

17. The method of claim 15 , wherein a fan is enabled and a compressor is disabled when the dehumidifier operates in the defrost mode.

18. The method of claim 15 , wherein the method further comprises:

determining whether a measured relative humidity is greater than a predetermined relative humidity set point;

in response to determining that the measured relative humidity is greater than the predetermined relative humidity set point, setting the dehumidifier to the dehumidifying mode.

19. The method of claim 18 , wherein the method further comprises:

in response to determining that the measured relative humidity is equal to or less than the predetermined relative humidity set point, setting the dehumidifier to a dehumidistat mode.