Energy efficient heat pump systems for water heating and air conditioning

A heat pump system for water heating and air conditioning, said system comprising:

• a compressor for circulating a refrigerant fluid through said system;
• a water tank for storing water;
• a first heat exchanger for heating water in said water tank;
• a second heat exchanger for rejecting or extracting heat to or from an outdoor environment;
• a third heat exchanger and associated fan for conditioning and supplying air to an indoor space, wherein said system is adapted so that:
• when heating water stored in the water tank requires heating, the refrigerant fluid exhausted from the compressor passes through the first heat transfer heat to the water in the water tank and then passes trough the second heat exchanger;
• and
• after the water in the water tank is heated to a predetermined temperature, the refrigerant fluid exhausted from the compressor bypasses the first heat exchanger and is directly passed to the second heat exchanger to exhaust heat to the outdoor environment.