There is provided a HVAC system comprising: a fluid circuit for conveying a refrigerant; a compressor for compressing the refrigerant; three heat exchangers defining an evaporator, an outdoor exchanger and a heat recovery exchanger provided along the fluid circuit; an expansion valve provided along the fluid circuit; and a receiver connected in parallel to the expansion valve, wherein a fill valve is located between the receiver and a connection upstream of the expansion valve and a drain valve is located between the receiver and a connection downstream of the expansion valve; wherein the fluid circuit comprises a plurality of valves which are configured to be controlled based on a selected operating mode such that at least one of the outdoor exchanger and the heat recovery exchanger is connected to a discharge line of the compressor and in series with one of the other heat exchangers which is connected to a suction line of the compressor, with the expansion valve disposed between the heat exchangers; wherein the fill and drain valves are configured to be controlled to store a volume of refrigerant in the receiver so as to provide an effective refrigerant charge in the fluid circuit that corresponds to the selected operating mode.

A header includes a plurality of branch tubes and a header manifold. If refrigerant flowing into the header manifold forms a pattern of annular flow or churn flow, tips of the branch tubes inserted into the header manifold pass through a liquid-phase portion having a thickness δ [m] and reach a gas-phase portion. The thickness δ [m] of the liquid-phase portion is defined as δ=G×(1−x)×D/(4ρ.sub.L×U.sub.LS), where G is a flow speed [kg/(m.sup.2 s)] of the refrigerant, x is a quality of the refrigerant, D is an inside diameter [m] of the header manifold, ρ.sub.L is a liquid density [kg/m.sup.3] of the refrigerant, U.sub.LS is a reference apparent liquid speed [m/s] that is a maximum value within a range of variation in an apparent gas speed of the refrigerant flowing into a flow space of the header manifold. The reference apparent liquid speed U.sub.LS [m/s] is defined as G(1−x)/ρ.sub.L.

A header includes a plurality of branch tubes and a header manifold. If refrigerant flowing into the header manifold forms a pattern of annular flow or churn flow, tips of the branch tubes inserted into the header manifold pass through a liquid-phase portion having a thickness δ [m] and reach a gas-phase portion. The thickness δ [m] of the liquid-phase portion is defined as δ=G×(1−x)×D/(4ρ.sub.L×U.sub.LS), where G is a flow speed [kg/(m.sup.2 s)] of the refrigerant, x is a quality of the refrigerant, D is an inside diameter [m] of the header manifold, ρ.sub.L is a liquid density [kg/m.sup.3] of the refrigerant, U.sub.LS is a reference apparent liquid speed [m/s] that is a maximum value within a range of variation in an apparent gas speed of the refrigerant flowing into a flow space of the header manifold. The reference apparent liquid speed U.sub.LS [m/s] is defined as G(1−x)/ρ.sub.L.

Disclosed is a multiport distributor comprising: an elongated member comprising a plurality of inlet ports disposed along a first end of the elongated member, a plurality of first outlet ports disposed along a face of the elongated member, and a plurality of fluid passages disposed within the elongated member and extending between the plurality of inlet ports and the plurality of first outlet ports, wherein the plurality of fluid passages are substantially parallel to one another and configured to convey a fluid in a first direction, wherein the plurality of first outlet ports are configured to direct a fluid passing therethrough in a second direction, wherein the second direction is substantially perpendicular to the first direction.

Disclosed is a multiport distributor comprising: an elongated member comprising a plurality of inlet ports disposed along a first end of the elongated member, a plurality of first outlet ports disposed along a face of the elongated member, and a plurality of fluid passages disposed within the elongated member and extending between the plurality of inlet ports and the plurality of first outlet ports, wherein the plurality of fluid passages are substantially parallel to one another and configured to convey a fluid in a first direction, wherein the plurality of first outlet ports are configured to direct a fluid passing therethrough in a second direction, wherein the second direction is substantially perpendicular to the first direction.

A heat exchanger (100) and a multi-split system having the same are provided. The heat exchanger (100) includes: a manifold (1) including a main body (11), an inlet (12) disposed in a bottom portion of the main body (11) and a plurality of split-flow ports distributed in a side wall of the main body (11) along a length direction thereof, in which the main body (11) includes a plurality of pipes from bottom to top, the pipe located downstream has a smaller flow area than the pipe located upstream in each two adjacent pipes, each pipe has a height no greater than 0.5 m, and a number of the pipes is 2≦N≦3; a header (2) communicated with the manifold (1) via a plurality of heat exchange tubes spaced apart from one another along an up and down direction, the header (2) having an outlet (21) for discharging a refrigerant.

A vacuum adiabatic body and a refrigerator are provided. The vacuum adiabatic body includes a support that maintains a vacuum space between a first plate and a second plate. The support includes a first support plate provided by coupling at least two partial plates to support one of the first plate or the second plate, and a second support plate that supports the other one of the first plate or the second plate.

A vacuum adiabatic body and a refrigerator are provided. The vacuum adiabatic body includes a support that maintains a vacuum space between a first plate and a second plate. The support includes a first support plate provided by coupling at least two partial plates to support one of the first plate or the second plate, and a second support plate that supports the other one of the first plate or the second plate.

A heat exchanger includes a fin group and a tube group for a heat exchange medium. The fin group includes plate fins each of which is shaped as a flat polygonal plate having a first acute-angled corner. The plate fins are spaced by gaps through which air for air conditioning passes and arranged such that the air for air conditioning flows in a first direction along one of sides forming the first corner. The tube group includes heat transfer tubes which meander in the first direction. The heat transfer tubes includes fin-mounted portions mounted to and penetrating through the fin group. On the plate fin, between first fin-mounted portions adjacent to one another in the first direction, there are second fin-mounted portions adjacent to the first fin-mounted portions in a direction orthogonal to the first direction.

A heat exchanger includes a fin group and a tube group for a heat exchange medium. The fin group includes plate fins each of which is shaped as a flat polygonal plate having a first acute-angled corner. The plate fins are spaced by gaps through which air for air conditioning passes and arranged such that the air for air conditioning flows in a first direction along one of sides forming the first corner. The tube group includes heat transfer tubes which meander in the first direction. The heat transfer tubes includes fin-mounted portions mounted to and penetrating through the fin group. On the plate fin, between first fin-mounted portions adjacent to one another in the first direction, there are second fin-mounted portions adjacent to the first fin-mounted portions in a direction orthogonal to the first direction.