# Development of a Low-Cost Automated Demand Response Controller for Home Energy Management
## 3 Results
### Load Reduction
Figure 14a depicts the current (\(I_{rms}\) as Equation (2) and labeled as I) of the air conditioner and room temperature (labeled as T) changes for Case 1. At 11 a.m. on 2 August, the AC was turned on and running in cooling mode, the outdoor temperature was 33 \({}^{\circ}\)C, the initial indoor temperature was 31.2 \({}^{\circ}\)C, and the temperature setting of the AC was 25 \({}^{\circ}\)C. The air conditioner's current began to rise to 11 A, and the indoor temperature began to decrease. When the indoor temperature dropped below the set temperature 25 \({}^{\circ}\)C, the air conditioner operated in fanning mode until the indoor temperature exceeded the setting temperature (with some fluctuation due to measurement errors on the temperature sensor). There are two times of fanning modes, and the duration of each fanning mode is short because the indoor temperature increases. Figure 14b shows the corresponding energy consumption (\(E\) as Equation (4) and labeled as E) and room temperature (labeled as T) variations for this case. The total energy consumption is 7.14 kWh. \begin{table}
\begin{tabular}{c c c} \hline
**Case ID** & **1** & **2** \\ \hline Date & 2 August & 3 August \\ Starting time & 11:00 & 11:00 \\ Ending time & 14:00 & 14:00 \\ Outdoor temperature & 33 & 32 \\ Indoor initial temperature & 31.2 & 30.9 \\ AC temperature setting & 25 & 26 \\ \hline \end{tabular}
\end{table} 
Table 4: Scenarios w/o participating in ADR programs. \begin{table}
\begin{tabular}{c c c c} \hline
**Case ID** & **A** & **B** & **C** \\ \hline Date & 4 August & 5 August & 6 August \\ Starting time & 11:00 & 11:00 & 11:00 \\ Ending time & 14:00 & 14:00 & 14:00 \\ \hline Outdoor temperature & 33 & 34 & 34 \\ Indoor initial temperature & 31.3 & 31.3 & 33.1 \\ AC temperature setting & 25 & 25 & 25 \\ Duration of cooling mode & 15 & 30 & 45 \\ Duration of fanning mode & 15 & 15 & 15 \\ Duty cycle & 0.50 & 0.67 & 0.75 \\ Cycles & 6 & 4 & 3 \\ \hline \end{tabular}
\end{table} 
Table 5: Different duty cycles for participating in ADR programs. To test the effect of the AC temperature setting on energy consumption, the AC temperature setting was now changed to 26 \({}^{\circ}\)C. Figure 15a depicts the current of the AC and room temperature changes for Case 2. At 11 a.m. on 3 August, the AC was turned on, the outdoor temperature was 32 \({}^{\circ}\)C which was 1 \({}^{\circ}\)C lower than that of Case 1, the indoor temperature was 30.9 \({}^{\circ}\)C which was close to that of Case 1, and the temperature setting of the AC was 25 \({}^{\circ}\)C. There are seven times of fanning modes, and the duration of the fanning mode is short also. Figure 15b shows the energy consumption and temperature variations for this case. The total energy consumption is 6.51 kWh. Compared with Case 1, Case 2 can save 0.63 kWh (8.8%) energy consumption. The demand response controller can receive a load reduction command of the demand response algorithm from the VEN through PLC. Figure 16a depicts variations of the current of the AC and room temperature for Case A. At 11 a.m. on 4 August, the AC was turned on in cooling mode for 15 min and in fanning mode for another 15 min, and this cycle was repeated. The outdoor temperature was 33 \({}^{\circ}\)C. During the first cycle, when in cooling mode, the indoor temperature dropped from 31.3 \({}^{\circ}\)C to 27.1 \({}^{\circ}\)C, and when in fanning mode, room temperature increased from 27.1 \({}^{\circ}\)C to 29.4 \({}^{\circ}\)C. Afterward, the room temperature varied in the range from 26.1 \({}^{\circ}\)C to 29.4 \({}^{\circ}\)C. Generally, the power consumed in fanning mode is much less than in cooling mode. Figure 16b shows this case's corresponding energy consumption and temperature variations. The total energy consumption is 3.86 kWh. Figure 14: Case 1—temperature setting at 25 \({}^{\circ}\)C. (**a**) Current and temperature. (**b**) Temperature and energy consumption.