Compartmentalized transport refrigeration system

A compartmentalized transport refrigeration system, comprising:

• a trailer having a first compartment,
• a host refrigeration unit for controlling the air temperature of said first compartment via heating, cooling and null modes,
• said host unit comprising a closed fluid circuit which includes a compressor, condenser, receiver, evaporator, accumulator, and liquid, hot gas and suction lines,
• first means for selectively enabling and blocking fluid flow from the high pressure side of said compressor to said condenser when said host unit is in a cooling mode,
• a second compartment in said trailer,
• a remote evaporator for controlling the air temperature of said second compartment via heating, cooling, and null modes,
• said remote evaporator including liquid, hot gas and suction lines connected to the liquid, hot gas and suction lines, respectively, of said host unit,
• second, third and fourth means for respectively and selectively enabling and blocking fluid flow between said remote liquid, hot gas and suction lines and said host unit,
• one-way by-pass means interconnecting the suction line of said remote evaporator and the receiver of said host unit,
• and control means for selecting the fluid blocking positions of said first, second and fourth means when the third means connects the hot gas line of the host unit to the remote evaporator, to direct the output of the compressor to the remote evaporator and cause the one-way by-pass means to connect the remote suction line to the receiver, to enhance the heating capability of the remote evaporator.