Question

Your house has an electric water heater. Several friends are visiting you over the weekend and they are taking consecutive showers. Assume that at the maximum heating level, the heater uses 5 kW of electricity. The water use rate is a continuous 4 gallons per minute with the new water saving showerhead you recently installed. Your very old showerhead had used 5 gallons per minute. You replaced the showerhead because you learned that heating water was the second highest energy use in your home. By slowing the flow of water through the heater, the water temperature should increase to a higher temperature. (a) What is the change in temperature (DT) for the old showerhead? (b) What is the change in temperature (DT) for the new showerhead? Assume the system is at steady sate, and all of the 5 kW energy used is heating the water.

Answer 1