Apparatus comprising: a refrigerated bulk fluid tank; refrigeration means for selectively refrigerating or heating fluid stored in said tank; and at least one four-way valve in fluid communication with said refrigeration means wherein said four-way valve comprises: a first port, second port, third port, and fourth port; and a valve member movable between a first position and a second position wherein, in said first position, fluid is flowable along a first flow path between said first port and said second port and along a second flow path between said third port and said fourth port, and wherein, in said second position, fluid is flowable along a third flow path between said first port and said forth port and along a fourth flow path between said third port and said second port, characterized in that the apparatus also comprises first thermal communication means for transporting heat between fluid stored in said tank and said refrigeration means, having a first closed loop fluid circuit extending between said tank and said refrigeration means, a first part of said first circuit being part of a first heat exchanger providing thermal communication between fluid stored in said tank and fluid in said first fluid circuit; and a second thermal communication means for transporting heat between said refrigeration means and from ambient fluid, having a second closed loop fluid circuit extending from said refrigeration means, a first part of said second circuit being part of a second heat exchanger providing thermal communication between ambient fluid and fluid in said second fluid circuit. a refrigerated bulk fluid tank; refrigeration means for selectively refrigerating or heating fluid stored in said tank; and at least one four-way valve in fluid communication with said refrigeration means wherein said four-way valve comprises: a first port, second port, third port, and fourth port; and a valve member movable between a first position and a second position wherein, in said first position, fluid is flowable along a first flow path between said first port and said second port and along a second flow path between said third port and said fourth port, and wherein, in said second position, fluid is flowable along a third flow path between said first port and said forth port and along a fourth flow path between said third port and said second port, characterized in that the apparatus also comprises first thermal communication means for transporting heat between fluid stored in said tank and said refrigeration means, having a first closed loop fluid circuit extending between said tank and said refrigeration means, a first part of said first circuit being part of a first heat exchanger providing thermal communication between fluid stored in said tank and fluid in said first fluid circuit; and a second thermal communication means for transporting heat between said refrigeration means and from ambient fluid, having a second closed loop fluid circuit extending from said refrigeration means, a first part of said second circuit being part of a second heat exchanger providing thermal communication between ambient fluid and fluid in said second fluid circuit. a first port, second port, third port, and fourth port; and a valve member movable between a first position and a second position wherein, in said first position, fluid is flowable along a first flow path between said first port and said second port and along a second flow path between said third port and said fourth port, and wherein, in said second position, fluid is flowable along a third flow path between said first port and said forth port and along a fourth flow path between said third port and said second port, characterized in that the apparatus also comprises first thermal communication means for transporting heat between fluid stored in said tank and said refrigeration means, having a first closed loop fluid circuit extending between said tank and said refrigeration means, a first part of said first circuit being part of a first heat exchanger providing thermal communication between fluid stored in said tank and fluid in said first fluid circuit; and a second thermal communication means for transporting heat between said refrigeration means and from ambient fluid, having a second closed loop fluid circuit extending from said refrigeration means, a first part of said second circuit being part of a second heat exchanger providing thermal communication between ambient fluid and fluid in said second fluid circuit.