The energy testing was carried out to measure the power consumption of our system over a long period of time. The controlling temperature was set at 24°C and the state of the relays was measured for nearly an hour.

 

From knowing the second-by-second breakdown of when the relays were active it was possible to identify which heaters were active and at what time. From this, knowing the power consumption of a single heater (40W), it was possible to calculate an average power over the period - 49.01W. This figure is still quite inaccurate as it neglects to consider the fact that the control system itself draws a small amount of power on top of this, it neglects to consider that the there may be deviation from the manufacturers stated value of 40W, and it doesn't consider the fan. To view the full energy consumption experimental results please download the excel document from the link provided here.

 

The fan is rated at 1.6W at full power, and adding this to the measured value, gives a power consumption of 50.6W. In addition to this, a 10% margin of error was adopted to compensate for the control system and the deviation from manufacturer specifications. This gives a total power consumption for 24°C (our initial target) of between 45.5W and 55.7W.

 

In reality, this figure would be able to be reduced somewhat, as less of a control system would be required (no measurements required etc.) and the heating efficiency would be increased.