A refrigerant-based thermal energy management system is provided, including an external unit outside of a controlled region that exchanges heat with an outside area. The external unit includes a compressor, a gas-phase valve array, and a manifold assembly with multiple ports affording dynamic selection of connection to either the compressor suction or output. The external unit includes a liquid-phase manifold with multiple ports and a complete internal refrigerant cycle loop composed of the compressor, a condenser and an evaporator. At least one service device is thermally coupled with the external unit. A 2-pipe bus allows each service device to be independently connected to one gas-phase manifold port and one liquid- phase manifold port, allowing the service devices to be independently connected in parallel with either the external unit condenser or the external unit evaporator. The direction and rate of refrigerant flow is independently controlled for each service device.