High efficiency pool heating system and power unit

A power unit for compressing gaseous fluids comprising:

• a body, said body including a plurality of first enclosed chambers;
• a plurality of first pistons, each piston movably mounted in one of said first chambers;
• a plurality of first rolling diaphragms, each diaphragm extending across a first chamber and supported on a first piston, each first rolling diaphragm separating a first side from a second side of said first chamber;
• first valve means for alternatively delivering relatively high pressure first working fluid to said first sides of said first chambers and exhausting said first working fluid from said first sides of said first chambers, whereby said first pistons are urged to reciprocate;
• at least one second enclosed chamber, a second movable member mounted in said second chamber and wherein movement of said second movable member compresses a working fluid in said second enclosed chamber;
• and
• connecting means for mechanically connecting said first pistons to said second movable member, whereby movement of said first pistons moves said second member to compress working fluid in said second chamber;
• said first valve means comprising a rotatable element having a pair of opposed facing surfaces, and a valve body having a pair of abutting surfaces, said element disposed between said abutting surfaces;
• said rotatable element including at least one first fluid passage extending traversely therethrough;
• a first abutting surface of said pair including a first fluid opening in fluid communication with relatively high pressure first working fluid, and a fourth fluid opening in fluid communication with a first side of a first chamber of said power unit, said first and fourth fluid openings angularly displaced from one another on said first abutting surface by a first angular displacement;
• said second abutting surface of said pair on said valve body including a third fluid opening in fluid communication with said first side of the first chamber of said power unit, and a second fluid opening in fluid communication with relatively lower fluid pressure, said third and fourth fluid opening disposed on said second abutting surface by said first angular displacement;
• said valve means further comprising means for rotating said rotatable element to alternatively place in fluid communication said first and third, or said second and fourth, fluid openings.

A power unit for driving at least one working member, comprising:

• a body, said body including at least one first chamber;
• a first piston movably mounted in said first chamber;
• a first rolling diaphragm extending across said first chamber and supported on the first piston, said first rolling diaphragm separating a first side from a second side of said first chamber;
• first valve means for alternatively delivering relatively high pressure first working fluid to said first side of said first chamber and exhausting said first working fluid from said first side of said first chamber, whereby said first piston is urged to reciprocate;
• and, connecting means for connecting said first piston to a working member,
• wherein said first valve means comprises a rotatable element having a pair of opposed facing surfaces, and a valve body having a pair of abutting surfaces, said element disposed between said abutting surfaces;
• said rotatable element including at least one first fluid passage therethrough;
• a first abutting surface of said pair including a first fluid opening in fluid communication with relatively high fluid pressure first working fluid, and a fourth fluid opening in fluid communication with a first side of said first chamber, said first and fourth fluid openings angularly displaced from one another on said first abutting surface by a first angular displacement;
• said second abutting surface of said pair including a third fluid opening in fluid communication with said first side of a first chamber and a second fluid opening in fluid communication with relatively lower fluid pressure, said third and second fluid openings disposed on said second abutting surface by said first angular displacement;
• said valve means further comprising means for rotating said rotatable element to alternatively place in fluid communication said first and third, or said second and fourth, fluid openings.