Electric Water Heater Energy Efficiency Test Equipment

Electric Water Heater Energy Efficiency Test Equipment

Standard:

IEC 60379: 1987 Methods for measuring the performance of electric storage water-heaters for household purposes.

Application:

Automatic testing system to evaluate the energy efficiency of electric storage water heaters.

Test items:

(1) Heating efficiency;

(2) Standing loss per 24 h;

(3) Hot-water output rate;

(4) Deviation from dial calibration, Cyclic temperature variation (differential);

Methods:

The complete testing system includes a water supply subsystem, hot water outlet subsystem, hardware subsystem, and software subsystem. An application program was developed using Visual Basic to acquire the sensor data and transmit it in real time to a database server. The energy efficiency evaluating process was controlled by the application software,by combining the data acquisition technology, communication technology, and program logical control technology.

Testing conditions:

The ESWH energy efficiency measurements should be carried out in the following conditions:

The air speed surrounding the heater in the testing room should not be greater than 0.25 m/s;

The ambient temperature should be kept at (20°C ± 2°C);

The relative humidity should not exceed 85%;

The water heater should work at the specified power; the actual power should not deviate more than ±5% from the rated power;

The inlet water temperature should remain at (15°C ± 2°C);

The water heater should work as in a normal installation; for open-outlet ESWHs, the inlet valve should be closed; for unvented ESWHs, the internal pressure should be kept at 0.28 MPa;

The ESWH thermostat should be adjusted such that the mean water temperature θM is at (65°C ± 3°C). The thermostat setting should remain unchanged throughout the tests. For ESWHs where an adjustable thermostat is not provided for the user, an external thermostat that can be set should be supplied.