STRATIFICATION IN SOLAR DOMESTIC HOT WATER STORAGE TANKS

ABSTRACT Promotion of stratification in a solar storage tank can increase the performance of a domestic hot water system by up to 15 percent. The degree of stratification in the storage tank for five systems was investigated. These were: 1) a single tank closed-loop system with a coil-in-tank heat exchanger; 2) a double tank closed-loop system with a coil-in-tank heat exchanger; 3) a direct draindown system in which the tank water is circulated through the solar collectors; 4) a thermosiphon system; 5) a closed-loop system with an external thermosiphon heat exchanger. This paper includes a description of the systems and experimental test results.