Abstract: A module for constructing therefrom a heat exchanger is provided. The module includes two manifolds and a plurality of parallelly arranged mats spanning between the manifolds. Each mat includes a plurality of heat exchange tubes arranged so as to define a plane, the heat exchange tubes being in fluid communication with the manifolds and spanning therebetween. Each of the manifolds includes selectively sealable end openings formed in facing ends thereof and defining a longitudinal flow path substantially perpendicular to the tubes and parallel with the planes defined thereby. Each of the manifolds further includes selectively sealable side openings on facing sides thereof and each defining a lateral flow path substantially perpendicular to the longitudinal flow path and to the planes defined by the tubes.

Abstract: A solar water-heating panel is provided, comprising a plurality of risers configured for utilizing solar radiation impinging thereon to heat a fluid therein. Each riser comprises a riser wall defining a fluid path for flow therethrough of the fluid. The panel further comprises one or more headers for facilitating delivery of the fluid between the panel and an external source of the fluid. The risers are parallely-arranged and separate from one another, and each comprises a longitudinal fin projecting sidewardly therefrom toward, and contacting, an adjacent riser.

Abstract: A module for constructing therefrom a heat exchanger is provided. The module includes two manifolds and a plurality of parallely arranged mats spanning between the manifolds. Each mat includes a plurality of heat exchange tubes arranged so as to define a plane, the heat exchange tubes being in fluid communication with the manifolds and spanning therebetween. Each of the manifolds includes selectively sealable end openings formed in facing ends thereof and defining a longitudinal flow path substantially perpendicular to the tubes and parallel with the planes defined thereby. Each of the manifolds further includes selectively sealable side openings on facing sides thereof and each defining a lateral flow path substantially perpendicular to the longitudinal flow path and to the planes defined by the tubes.

Abstract: A solar water-heating panel is provided, comprising a plurality of risers configured for utilizing solar radiation impinging thereon to heat a fluid therein. Each riser comprises a riser wall defining a fluid path for flow therethrough of the fluid. The panel further comprises one or more headers for facilitating delivery of the fluid between the panel and an external source of the fluid. The risers are parallely-arranged and separate from one another, and each comprises a longitudinal fin projecting sidewardly therefrom toward, and contacting, an adjacent riser.