Improving the heat retention of integrated collector/storage solar water heaters using Phase Change Materials Slurries

Abstract

SYNOPSIS Integrated Collector/Storage Solar Water Heaters are very efficient at collecting solar radiation and transferring thermal energy to store during the day in northern latitudes. However the culture and lifestyle in these latitudes tend to require hot water at the beginning of the day and not at the end. The use of phase change materials, and specifically phase change material slurries, as a heat retention material, to hold heat overnight so that it can be used the next day has been investigated. While it was found that with the right concentration of PCM in a carrier fluid a temperature of 50°C could be maintained until 6am the following day, the nature of the slurry material over time disaggregates and quickly becomes unusable.