SOLAR THERMAL ACTIVE SYSTEMS: FROM CLOSED FORM MODELS TO SIMPLE SIZING RULES FOR COLLECTOR CIRCUITS

ABSTRACT A simple closed-form model of thermal solar active systems (Space or Water heating) is presented. It deals both with fully-mixed storage and perfectly stratified storage and enables a better understanding of physical phenomena occurring within the system (e.g. low collector flow-rate effects). Direct application of this model makes it possible to establish partial sizing rules for the system components: storage capacity, storage insulation, pipe insulation, heat-exchanger area, collector flow-rate.