Portable method and apparatus for monitoring refrigerant-cycle systems
View Patent ↗A portable monitoring system that monitors various aspects of the operation of a refrigerant-cycle system is described. In one embodiment, the system includes a processor that measures power provided to the refrigerant-cycle system and gathers data from one or more sensors and uses the sensor data to calculate a figure of merit related to the efficiency of the system. In one embodiment, the measurements performed by the monitoring system include one or more of: an evaporator input air temperature, an evaporator output air temperature, evaporator air flow, evaporator air humidity, condenser air input temperature, condenser air output temperature sensor, electrical power. In one embodiment, the portable monitoring system receives information about the refrigerant-cycle system from either the system itself or from a computer network.
1. A monitoring system for monitoring the operation of a refrigerant-cycle system, the monitoring system comprising:
a monitoring unit including a processing system, a display, and one or more user input devices;
an airflow sensor provided to the monitoring unit and configured to generate airflow data;
a power sensor provided to the monitoring unit and configured to generate power data;
an ambient temperature sensor provided to the monitoring unit and configured to generate ambient air temperature data for air provided to an evaporator of the refrigerant-cycle system; and
a network interface provided to the monitoring unit,
the monitoring unit using the network interface to query and receive performance information regarding an HVAC unit identified by a model number,
the performance information comprising efficiency data specifying, for an input present ambient air temperature, a maximum expected efficiency of the HVAC unit according to the input present ambient air temperature,
the monitoring unit determining a present maximum expected efficiency of the HVAC unit, wherein the present maximum expected efficiency of the HVAC unit is determined using the input present ambient air temperature and using an input present ambient humidity,
the monitoring unit using the airflow data, the power data, output air temperature data for air flowing from the evaporator, and the ambient air temperature data to compute a present efficiency of the HVAC unit, and
the monitoring unit using the display to display a relationship between the present efficiency and the present maximum expected efficiency.
2. The monitoring system of claim 1 , wherein the processing system is configured to calculate energy usage.
3. The monitoring system of claim 1 , wherein the processing system is configured to calculate energy costs due to inefficient operation of the refrigerant-cycle system.
4. The monitoring system of claim 1 , wherein the processing system is configured to identify performance problems due to low airflow.
5. The monitoring system of claim 1 , wherein the processing system is configured to identify performance problems due to excessive load.
6. The monitoring system of claim 1 , wherein the processing system is configured to identify performance problems due to refrigerant undercharge.
7. The monitoring system of claim 1 , wherein the processing system is configured to identify performance problems due to refrigerant overcharge.
8. The monitoring system of claim 1 , wherein the processing system is configured to identify performance problems due to inefficient compressor operation.
9. The monitoring system of claim 1 , wherein the processing system is configured to provide data for plots of energy usage and costs.
10. The monitoring system of claim 1 , wherein the processing system is configured to provide data related to operation of the refrigerant-cycle system to a remote monitoring center.
11. The monitoring system of claim 1 , wherein the network interface communicates with an RFID tag of the HVAC unit to obtain the performance information related to the maximum expected efficiency.
12. The monitoring system of claim 1 , wherein the monitoring unit communicates with the power sensor via wireless communication.
13. The monitoring system of claim 1 , wherein the monitoring system is configured with data regarding a type of refrigerant used in the HVAC unit.
14. The monitoring system of claim 1 , wherein the monitoring system is configured with data regarding characteristics of a condenser of the refrigerant-cycle system.
15. The monitoring system of claim 1 , wherein the monitoring system is configured with data regarding characteristics of the evaporator.
16. The monitoring system of claim 1 , wherein the monitoring unit communicates with the ambient temperature sensor via wireless communication.
17. The monitoring system of claim 1 , wherein the monitoring unit communicates with the airflow sensor via wireless communication.
18. The monitoring system of claim 1 , further comprising an adapter to adapt the airflow sensor to an exhaust vent of the HVAC unit.
19. The monitoring system of claim 1 , further comprising an adapter to adapt the airflow sensor to an intake vent of the HVAC unit.
20. The monitoring system of claim 1 , further comprising a computer-readable interface configured to provide the efficiency data, wherein the efficiency data includes at least one of (i) parameters for calculating the maximum expected efficiency of the HVAC unit based on the input present ambient air temperature and (ii) algorithms for calculating the maximum expected efficiency of the HVAC unit based on the input present ambient air temperature.
21. The monitoring system of claim 1 , wherein the efficiency data specifies, for the input present ambient air temperature and the input present ambient humidity, the maximum expected efficiency of the HVAC unit.
22. The monitoring system of claim 1 , further comprising a humidity sensor configured to generate the input present ambient humidity.
23. The monitoring system of claim 22 , wherein the humidity sensor is configured to measure the input present ambient humidity of the air provided to the evaporator.