An HVAC system, comprising: a plurality of tubing sections 34 connecting a source of refrigerant to a plurality of distributed cooling units; characterised by: a plurality of Y connectors 26 for attachment to said tubing sections with each Y connector comprising a Y connector hub with three threaded hub openings, and three hub connectors 28 for threading into each of said threaded hub openings, with said hub connectors having a dielectric layer 24 on an inner surface and on an outer surface and a press fit joint on a first end, and a thread fit joint 40 on a second end, for attachment to said tubing sections 34 to said Y connector hub; and a plurality of generally cylindrical hollow tubing connectors 12, 36 with a dielectric coating layer 24 on an inner surface and on an outer surface, with said tubing connectors 12, 36 having a press fit joint on a first end 18 and a press fit joint on a second end 20, for joining two tubing sections 34; and wherein said Y connectors 26 and said tubing connectors 12, 36 form a network of tubing sections to deliver and return predetermined quantities of refrigerant from said source of refrigerant to said distributed cooling units, with said system comprising press fit and thread fit joints assembled without heat. a plurality of tubing sections 34 connecting a source of refrigerant to a plurality of distributed cooling units; characterised by: a plurality of Y connectors 26 for attachment to said tubing sections with each Y connector comprising a Y connector hub with three threaded hub openings, and three hub connectors 28 for threading into each of said threaded hub openings, with said hub connectors having a dielectric layer 24 on an inner surface and on an outer surface and a press fit joint on a first end, and a thread fit joint 40 on a second end, for attachment to said tubing sections 34 to said Y connector hub; and a plurality of generally cylindrical hollow tubing connectors 12, 36 with a dielectric coating layer 24 on an inner surface and on an outer surface, with said tubing connectors 12, 36 having a press fit joint on a first end 18 and a press fit joint on a second end 20, for joining two tubing sections 34; and wherein said Y connectors 26 and said tubing connectors 12, 36 form a network of tubing sections to deliver and return predetermined quantities of refrigerant from said source of refrigerant to said distributed cooling units, with said system comprising press fit and thread fit joints assembled without heat. a plurality of Y connectors 26 for attachment to said tubing sections with each Y connector comprising a Y connector hub with three threaded hub openings, and three hub connectors 28 for threading into each of said threaded hub openings, with said hub connectors having a dielectric layer 24 on an inner surface and on an outer surface and a press fit joint on a first end, and a thread fit joint 40 on a second end, for attachment to said tubing sections 34 to said Y connector hub; and a plurality of generally cylindrical hollow tubing connectors 12, 36 with a dielectric coating layer 24 on an inner surface and on an outer surface, with said tubing connectors 12, 36 having a press fit joint on a first end 18 and a press fit joint on a second end 20, for joining two tubing sections 34; and wherein said Y connectors 26 and said tubing connectors 12, 36 form a network of tubing sections to deliver and return predetermined quantities of refrigerant from said source of refrigerant to said distributed cooling units, with said system comprising press fit and thread fit joints assembled without heat.