Bosman, I.E., North-West University, Potchefstroom, South Africa; Grobler, L.J., North-West University, Potchefstroom, South Africa; Dalgleish, A.Z., North-West University, Potchefstroom, South Africa
Electric hot water heater blankets are being used as a demand-side management (DSM) measure to save electricity consumption in residential areas. The purpose of this study was to determine the impact of installing blankets to hot water heaters. A residential apartment building consisting of eighteen similar flats were used for the study. All the flats were equipped with the same 100-litre hot water heaters. The set points of the geysers used in the test were set at 60°C and 70°C. The standing losses were measured over an extended period and related to the ambient temperatures. The data was then used to develop a generic equation describing the standing losses of the specific hot water heaters using the ambient and set point temperatures as inputs. The hot water heaters were covered with insulation blankets and the study was repeated. A generic equation was again developed for the heaters with blankets. Finally, the generic equations were applied to determine the annual savings that would be realised if the hot water heaters were situated in Pretoria, Cape Town, Johannesburg, Durban and Bloemfontein, using hourly meteorological weather data of the different locations.