Performance characterisation and energy savings of uncovered swimming pool solar collectors under reduced flow rate conditions

The effects of reduced flow rates on the performance and effectiveness of domestic unglazed, uninsulated pool solar collector heaters are investigated. The study shows electrical energy savings in excess of 80% are achievable for typical solar collectors operating at flow rates reduced by up to 75% while collector efficiency is only reduced by approximately 10–15%. The reduction of electrical energy required for pumping and the increased COP of reduced flow through typical pool solar thermal collectors is shown to far outweigh the small loss of collector performance attributable to the change in flow rates. The ratio of thermal energy delivered to the electrical energy supplied was improved in the order of 400% for the collector tested.

► Effects of reduced flow rates on pool solar collectors investigated.
► Flow rate reduction of 75% from typical only reduces efficiency 10–15%.
► Ratio of thermal energy delivered to electrical energy supplied improved ∼400%.