%0 Journal Article %T IMPROVING THE EFFICIENCY OF SOLAR WATER HEATERS %A Ilyin, R.. %A Shishkin, N.. %K solar energy collectors, solar water heaters, multistage solar collectors, energy efficiency, technical and economic effectiveness %J Vestnik of Astrakhan State Technical University %D 2016 %N 2016 %P 8 %I Astrakhan State Technical University