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Abstract: This paper implements a normalization/regression-based approach to estimate the kWh energy and kW savings from an experimental OEEP (operational energy-efficiency program) for municipal water pumping in California. The voluminous 1-min data collected in the course of the OEEP presents a unique opportunity to analyze how VSD (variable-speed drive) technology aided by a PLC (programmable-logic-controller) may improve municipal water pumping's operational energy efficiency. Our proposed approach enables a comparison of pump operations with and without the OEEP, yielding accurate estimates for kWh energy and kW capacity savings that are useful in evaluation, monitoring, and verification of the program. Our findings lead us to conclude that (a) variability of efficacy by analyzed pump sites suggests targeted implementation of the OEEP; and (b) for a correctly-sized pump operating near its optimal kW-output value, adding a VSD and PLC can actually harm the pumping system's overall energy-efficiency. [Copyright &y& Elsevier]

Abstract: Earlier studies used field testing of swimming pool temperatures to validate a mathematical model for predicting the temperature of an unheated pool. Combining those results with manufacturers’ data on the performance of vapor-compression air conditioners as a function of heat rejection temperature, the analyses in the paper suggest that rejecting air conditioning heat to a swimming pool can save approximately 25–30% of single-family residential cooling electricity use and reduce cooling electricity demand during peak conditions by 30–35%, as compared to using the same compressor to reject the heat to ambient air. The savings is expected to vary depending on the severity of the climate, as well as the pool temperature experienced during the summer. The original model was refined so as to accommodate air-conditioner heat rejection to predict pool temperatures based on weather data, pool size, shading of the pool, and air-conditioner heat rejection to the pool. The results of an experimental validation of the augmented pool thermal model are presented here. In addition, the model of a pool-coupled air conditioning system was used to develop a design tool for determining the pool size needed to absorb realistic heat rejection from air conditioners in various California climate zones. [Copyright &y& Elsevier]