By implementing (2) in Matlab/SIMULINK one can see the variation of the temperature of the hot water in the tank (TH) for various conditions. The heating element of the EWH is turned ON and OFF so as to keep TH within a tolerance band (+/- Δ) of Td. When the heating element of the EWH is ON, TH rises until it reaches (Td+Δ). Then the heating element is turned OFF and TH decreases until it reaches (Td-Δ), when the heating element is turned ON again. In this study, the rated power of the EWH (Prated) is assumed to be 5.5 kW and Td for the base case (Tdb) is set at 120 °F with Δ equal to 2.5 °F. The 24-hour hot water draw (Wd) profile used in this paper refers to the hourly profile proposed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) [8]. The other main parameters used in the simulations are shown in Table 1.