A multi-slab microchannel heat exchanger (20, 200, 400, 500, 600) comprising: a first slab (21, 210, 410, 510, 610), the first slab comprising: a first inlet header (23, 250, 350, 430, 560A, 640); a first outlet header (24, 260, 340, 440, 540A); and a first plurality of tubes (21A, 210A, 410A, 510A, 610A), wherein the first plurality of tubes is arranged successively in a direction along a length of the heat exchanger, each of the first plurality of tubes includes microchannels, the first plurality of tubes includes inlets and outlets, the inlets of the first plurality of tubes are in fluid communication with the outlets of the first plurality of tubes through the microchannels of the plurality of tubes, and the first inlet header is in fluid communication with the inlets of the first plurality of tubes, the first outlet header is in fluid communication with the outlets of the first plurality of tubes; a second slab (22, 220, 420, 520, 620) including a second inlet header (23, 270, 450, 560B, 650) and a second outlet header (24, 280, 460, 540B), the direction of the length of the heat exchanger being a direction extending from the first slab to the second slab; a first inlet connector (299A, 550A, 670C) fluidly connected to the first inlet header; a first outlet connector fluidly connected to the first outlet header; a second inlet connector (299C, 550B, 670B) fluidly connected to the second inlet header; and a second outlet connector fluidly connected to the second outlet header, wherein the first slab and the second slab are arranged successively in the direction along the length of the heat exchanger, the heat exchanger has a first end and a second end in the direction of the length of the heat exchanger, characterized in that the first inlet connector, the first outlet connector, the second inlet connector, and the second outlet connector are disposed at the first end of the heat exchanger. a first slab (21, 210, 410, 510, 610), the first slab comprising: a first inlet header (23, 250, 350, 430, 560A, 640); a first outlet header (24, 260, 340, 440, 540A); and a first plurality of tubes (21A, 210A, 410A, 510A, 610A), wherein the first plurality of tubes is arranged successively in a direction along a length of the heat exchanger, each of the first plurality of tubes includes microchannels, the first plurality of tubes includes inlets and outlets, the inlets of the first plurality of tubes are in fluid communication with the outlets of the first plurality of tubes through the microchannels of the plurality of tubes, and the first inlet header is in fluid communication with the inlets of the first plurality of tubes, the first outlet header is in fluid communication with the outlets of the first plurality of tubes; a first inlet header (23, 250, 350, 430, 560A, 640); a first outlet header (24, 260, 340, 440, 540A); and a first plurality of tubes (21A, 210A, 410A, 510A, 610A), wherein the first plurality of tubes is arranged successively in a direction along a length of the heat exchanger, each of the first plurality of tubes includes microchannels, the first plurality of tubes includes inlets and outlets, the inlets of the first plurality of tubes are in fluid communication with the outlets of the first plurality of tubes through the microchannels of the plurality of tubes, and the first inlet header is in fluid communication with the inlets of the first plurality of tubes, the first outlet header is in fluid communication with the outlets of the first plurality of tubes; a second slab (22, 220, 420, 520, 620) including a second inlet header (23, 270, 450, 560B, 650) and a second outlet header (24, 280, 460, 540B), the direction of the length of the heat exchanger being a direction extending from the first slab to the second slab; a first inlet connector (299A, 550A, 670C) fluidly connected to the first inlet header; a first outlet connector fluidly connected to the first outlet header; a second inlet connector (299C, 550B, 670B) fluidly connected to the second inlet header; and a second outlet connector fluidly connected to the second outlet header, wherein the first slab and the second slab are arranged successively in the direction along the length of the heat exchanger, the heat exchanger has a first end and a second end in the direction of the length of the heat exchanger, characterized in that the first inlet connector, the first outlet connector, the second inlet connector, and the second outlet connector are disposed at the first end of the heat exchanger.