An innovative benchmark testing to quantify saving by retrofitting geyser with hotspot device

摘要

Electrical geysers (high-pressure geyser, solar geyser or combinational geyser) are inefficient but widely used in the production of sanitary hot water in the residential sector. The focus of the study is to demonstrate that by installing the hotspot device on the electric element in the geyser a potential demand and energy saving can be achieved by virtue of sanitary hot water production. In this study, a 150 L, 3kW high-pressure geyser without a hotspot device and a 150 L, 3kW high-pressure geyser with a hotspot device were setup in the horizontal configuration at the Fort Hare Institute Research Center at Alice. Controlled volumes of hot water (150 L, 100 L and 50 L) were drawn off from each of the geyser cylinders while the elements were switched off. After completion of the specific hot water withdrawal from both cylinders, the electric elements were simultaneously switched on, and both geysers were allowed to heat up the water to its set point temperature of 55°C. It should be alluded that for each scenario of the withdrawal, the experiments were conducted for one month and in three periods of a day (morning, afternoon and evening) which concurs with the period of hot water demand. A data acquisition system was designed and build to monitor the power and energy consumption of the both hot water systems. The preliminary results depicted that the average demand reduction due to installation of the hotspot device on an existing geyser was 0.14 kW and the average saving on the energy consumed over the three heating scenarios was 0.27/kWh, respectively.