Domestic solar water preheating versus solar water heating: an economic evaluation

This paper analyses the feasibility of using unglazed solar collectors for domestic water heating in Brazil, in the 40/degree/C-50/degree/C temperature range. The analysis, carried out for the coldest main cities in Brazil, shows that a 50% reduction in hot water system initial cost can be achieved if unglazed collectors, with about 17% less area than the reference single glazed collector area are used. 3 refs.