A method for air conditioning including installing an air conditioning unit at a desired location. The air conditioning unit includes a housing that has air supply inlets and exhaust air outlets. The housing encloses a mode control unit that switches a zone coil associated with a zone from a cooling mode to a heating mode by switching from a cooling medium to a heating medium flowing through the zone coil. The zone coil receives the heating or cooling medium and conditions incoming air from a supply fan to be exhausted in a zone associated with the zone coil. A variable refrigerant flow cooling/heating unit provides a cooling medium or a heating medium at varying rates to control a temperature of a zone.

A ventilation air conditioning structure including a room that has a floor portion to a fourth wall portion, a first wall portion to be a building outer wall in which an air supply opening is formed in a vicinity of a third wall portion, and an air exhaust opening that is formed in a vicinity of the fourth wall portion. The ventilation air conditioning structure also includes an air conditioner that is disposed inside the room and where at least one of air sending openings of a room interior unit is capable of sending air in a direction of a second wall portion, and an external-air conditioner that is disposed outside the room. The external-air conditioner includes heat exchangers that are incorporated in a refrigerant circuit of the air conditioner via a branched pipe that is branched from a refrigerant piping and a casing that houses the heat exchangers.

A method for air conditioning including installing an air conditioning unit at a desired location. The air conditioning unit includes a housing that has air supply inlets and exhaust air outlets. The housing encloses a mode control unit that switches a zone coil associated with a zone from a cooling mode to a heating mode by switching from a cooling medium to a heating medium flowing through the zone coil. The zone coil receives the heating or cooling medium and conditions incoming air from a supply fan to be exhausted in a zone associated with the zone coil. A variable refrigerant flow cooling/heating unit provides a cooling medium or a heating medium at varying rates to control a temperature of a zone.

A method for air conditioning including installing an air conditioning unit at a desired location. The air conditioning unit includes a housing that has air supply inlets and exhaust air outlets. The housing encloses a mode control unit that switches a zone coil associated with a zone from a cooling mode to a heating mode by switching from a cooling medium to a heating medium flowing through the zone coil. The zone coil receives the heating or cooling medium and conditions incoming air from a supply fan to be exhausted in a zone associated with the zone coil. A variable refrigerant flow cooling/heating unit provides a cooling medium or a heating medium at varying rates to control a temperature of a zone.

A method for air conditioning including installing an air conditioning unit at a desired location. The air conditioning unit includes a housing that has air supply inlets and exhaust air outlets. The housing encloses a mode control unit that switches a zone coil associated with a zone from a cooling mode to a heating mode by switching from a cooling medium to a heating medium flowing through the zone coil. The zone coil receives the heating or cooling medium and conditions incoming air from a supply fan to be exhausted in a zone associated with the zone coil. A variable refrigerant flow cooling/heating unit provides a cooling medium or a heating medium at varying rates to control a temperature of a zone.

A method for air conditioning including installing an air conditioning unit at a desired location. The air conditioning unit includes a housing that has air supply inlets and exhaust air outlets. The housing encloses a mode control unit that switches a zone coil associated with a zone from a cooling mode to a heating mode by switching from a cooling medium to a heating medium flowing through the zone coil. The zone coil receives the heating or cooling medium and conditions incoming air from a supply fan to be exhausted in a zone associated with the zone coil. A variable refrigerant flow cooling/heating unit provides a cooling medium or a heating medium at varying rates to control a temperature of a zone.

A flexible duct system has fittings connecting sections of the flexible duct which are pulled taut between adjacent ones of the fittings. A first fitting has a first end and a second end. The second end is distally disposed from the first end and defines a second terminal end and having a second end profile. A second fitting has a forward end and a rearward end. The forward end preferably faces toward the first fitting, spaced apart from the second end of the first fitting. The forward end defines a third terminal end and a third end profile. The rearward end is distally disposed from the forward end, and defines a fourth terminal end and a fourth end profile. The end profiles preferably each include a tapered surface and a catch shoulder. The tapered surfaces circumferentially extend around a central axis of a respective end profile and face in directions which extend outward of the respective end profile with the tapered surfaces narrowing in the respective outwardly extending direction. The catch shoulders face in respective directions opposed to the outwardly extending directions and are spaced apart from respective outward terminal ends of the respective end profile to define abutments. The fittings are formed to provide Tee fittings, reducer fittings, and end caps, and include support members for securing the fittings in fixed positions. Some fittings have ends with spaced apart multiple end profiles of progressively reduced sizes with cut lines disposed between the multiple end profiles.

An air conditioning that includes a housing. The housing encloses a mode control unit that switches a zone coil associated with a zone from a cooling mode to a heating mode by switching from a cooling medium to a heating medium flowing through the zone coil. The zone coil receives the heating or cooling medium and conditions incoming air from a supply fan to be exhausted in a zone associated with the zone coil. A variable refrigerant flow cooling/heating unit provides a cooling medium or a heating medium at varying rates to control a temperature of a zone.

A method for air conditioning including installing an air conditioning unit at a desired location. The air conditioning unit includes a housing that has air supply inlets and exhaust air outlets. The housing encloses a mode control unit that switches a zone coil associated with a zone from a cooling mode to a heating mode by switching from a cooling medium to a heating medium flowing through the zone coil. The zone coil receives the heating or cooling medium and conditions incoming air from a supply fan to be exhausted in a zone associated with the zone coil. A variable refrigerant flow cooling/heating unit provides a cooling medium or a heating medium at varying rates to control a temperature of a zone.

Described herein are technologies for an enclosed, modular multi-zone variable refrigerant flow air conditioning system. In some implementations, the enclosed, modular multi-zone variable refrigerant flow air conditioning system may include a housing. The housing may have enclosed therein a variable refrigerant flow cooling/heating unit, a mode control unit, a return/exhaust fan, and a supply fan. The enclosed, modular multi-zone variable refrigerant flow air conditioning system may further include one or more units to receive a heating or cooling medium from the variable refrigerant flow cooling/heating unit to cool or heat air going to two or more zones. The enclosed, modular multi-zone variable refrigerant flow air conditioning system may be a modular unit transportable and installable as a single unit.