AWSWAH - the heat pipe solar water heater

An all weather heat pipe solar water heater (AWSWAH) comprising a collector of 4 m/sup 2/ (43 ft/sup 2/) and a low profile water tank of 160 liters (42 gal.) was developed. A single heat pipe consisting of 30 risers and two manifolds in the evaporator and a spiral condenser was incorporated into the AWSWAH. Condensate metering was done by synthetic fiber wicks. The AWSWAH was tested alongside two conventional solar water heaters of identical dimensions, an open loop system and a closed loop system. It was found that the AWSWAH was an average of 50% more effective than the open system in the temperature range 30-90 /sup 0/C (86-194 /sup 0/F). The closed loop system was the least efficient of the three systems.