Method and apparatus for monitoring a refrigeration-cycle system

1. A method of monitoring operation of a refrigerant-cycle system, the method comprising:

measuring an operating characteristic of a condenser unit using a condenser unit sensor, the condenser unit including a condenser and a compressor;

measuring an operating characteristic of an evaporator unit using an evaporator unit sensor, the evaporator unit including an evaporator and a fan, wherein the operating characteristic of the evaporator unit includes at least one of air pressure, air flow, and air temperature;

using an electrical sensor, measuring an electrical quantity indicative of power consumption of the refrigerant-cycle system; and

using a processing system, calculating an efficiency of the refrigerant-cycle system based on the power consumption of the refrigerant-cycle system, the operating characteristic of the condenser unit, and the operating characteristic of the evaporator unit.

2. The method of claim 1 further comprising:

calculating an amount of work done by the refrigerant-cycle system based on the operating characteristic of the condenser unit and the operating characteristic of the evaporator unit; and

calculating the efficiency of the refrigerant-cycle system based on the amount of work done by the refrigerant-cycle system and the power consumption of the refrigerant-cycle system.

3. The method of claim 1 further comprising transmitting the efficiency of the refrigerant-cycle system and an identification code of the refrigerant-cycle system to a remote monitoring system.

4. The method of claim 1 further comprising:

determining an expected efficiency of the refrigerant-cycle system based on an identification code of the refrigerant-cycle system; and

based on the efficiency of the refrigerant-cycle system and the expected efficiency of the refrigerant-cycle system, at least one of:

notifying an owner of the refrigerant-cycle system that the efficiency of the refrigerant-cycle system is low; and

notifying the owner of the refrigerant-cycle system to seek service.

5. The method of claim 1 further comprising:

determining an expected efficiency of the refrigerant-cycle system based on an identification code of the refrigerant-cycle system; and

determining a relative efficiency of the refrigerant-cycle system based on the expected efficiency and the efficiency of the refrigerant-cycle system.

6. The method of claim 5 further comprising, in response to the relative efficiency of the refrigerant-cycle system being less than a predetermined value, notifying an owner of the refrigerant-cycle system of at least one of (i) that the efficiency of the refrigerant-cycle system is low and (ii) to seek service.

7. The method of claim 5 further comprising selectively adjusting operation of the refrigerant-cycle system in response to the relative efficiency of the refrigerant-cycle system being less than a predetermined value for at least a predetermined period.

8. The method of claim 5 further comprising transmitting an instruction to a thermostat to increase a setpoint temperature in response to the relative efficiency of the refrigerant-cycle system being less than a predetermined value for a predetermined period, wherein the thermostat controls operation of the condenser unit and the evaporator unit based on the setpoint temperature.

9. The method of claim 5 further comprising determining, based on the identification code of the refrigerant-cycle system, whether to adjust operation of the refrigerant-cycle system.

10. The method of claim 1 wherein the operating characteristic of the evaporator unit includes an air pressure difference across the evaporator, and wherein the method further comprises

measuring a first temperature of air at a point prior to flowing through the evaporator using a first temperature sensor; and

measuring a second temperature of air at a point prior after flowing through the evaporator using a second temperature sensor, wherein the calculating the efficiency is further based on the first temperature and the second temperature.

11. A monitoring system for monitoring operation of a refrigerant-cycle system, the monitoring system comprising:

a condenser unit sensor measuring an operating characteristic of a condenser unit, the condenser unit including a condenser and a compressor;

an evaporator unit sensor measuring an operating characteristic of an evaporator unit, the evaporator unit including an evaporator and a fan, wherein the evaporator unit sensor is at least one of an air pressure sensor, an air flow sensor, and an air temperature sensor;

an electrical sensor measuring an electrical quantity indicative of power consumption of the refrigerant-cycle system; and

a processing system that calculates an efficiency of the refrigerant-cycle system based on the power consumption of the refrigerant-cycle system, the operating characteristic of the condenser unit, and the operating characteristic of the evaporator unit.

12. The monitoring system of claim 11 wherein the processing system:

calculates an amount of work done by the refrigerant-cycle system based on the operating characteristic of the condenser unit and the operating characteristic of the evaporator unit; and

calculates the efficiency of the refrigerant-cycle system based on the amount of work done by the refrigerant-cycle system and the power consumption of the refrigerant-cycle system.

13. The monitoring system of claim 11 further comprising a remote monitoring system, wherein the processing system transmits the efficiency of the refrigerant-cycle system and an identification code of the refrigerant-cycle system to the remote monitoring system.

14. The monitoring system of claim 11 further comprising a remote monitoring system that:

determines an expected efficiency of the refrigerant-cycle system based on an identification code of the refrigerant-cycle system; and

based on the efficiency of the refrigerant-cycle system and the expected efficiency of the refrigerant-cycle system, at least one of:

notifies an owner of the refrigerant-cycle system that the efficiency of the refrigerant-cycle system is low;

notifies the owner of the refrigerant-cycle system to seek service; and

selectively adjusts operation of the refrigerant-cycle system.

15. The monitoring system of claim 11 further comprising a remote monitoring system that:

determines an expected efficiency of the refrigerant-cycle system based on an identification code of the refrigerant-cycle system; and

determines a relative efficiency of the refrigerant-cycle system based on the expected efficiency and the efficiency of the refrigerant-cycle system.

16. The monitoring system of claim 15 wherein, in response to the relative efficiency of the refrigerant-cycle system being less than a predetermined value, the remote monitoring system notifies an owner of the refrigerant-cycle system of at least one of (i) that the efficiency of the refrigerant-cycle system is low and (ii) to seek service.

17. The monitoring system of claim 15 wherein the remote monitoring system selectively adjusts operation of the refrigerant-cycle system in response to the relative efficiency of the refrigerant-cycle system being less than a predetermined value for at least a predetermined period.

18. The monitoring system of claim 15 wherein:

the remote monitoring system transmits an instruction to a thermostat to increase a setpoint temperature in response to the relative efficiency of the refrigerant-cycle system being less than a predetermined value for a predetermined period, and

the thermostat controls operation of the condenser unit and the evaporator unit based on the setpoint temperature.

19. The monitoring system of claim 15 wherein the remote monitoring system determines, based on the identification code of the refrigerant-cycle system, whether to adjust operation of the refrigerant-cycle system.

20. The monitoring system of claim 11 further comprising:

a first temperature sensor measuring a first temperature of air at a point prior to flowing through the evaporator; and

a second temperature sensor measuring a second temperature of air at a point after flowing through the evaporator,

wherein the processing system calculates the efficiency also based on the first temperature and the second temperature,

wherein the evaporator unit sensor includes a differential pressure sensor, and

wherein the operating characteristic of the evaporator unit includes an air pressure difference across the evaporator.