Distributed Climate-Control Systems and Methods with Distributed Protection against Refrigerant Loss

Distributed Climate-Control Systems and Methods with Distributed Protection against Refrigerant Loss: the system includes a central condenser unit in combination with a distributed network of air handling units. Each air handler includes an evaporator, in which condensed refrigerant can undergo a phase change while absorbing heat of vaporization, plus a heat exchanger (e.g. a coil) which permits the heat absorption of the evaporator to be coupled to a forced airflow. Preferably the evaporator includes a metering device to provide variable refrigerant flow, and hence variable rates of heat transfer. The individual evaporators also include a sensor to detect ambient levels of the refrigerant, electrically operable cutoff valves which permit the evaporator to be isolated from both the liquid-phase and the gas-phase refrigerant flows. Local control logic is preferably connected to shut the cutoff valves whenever an ambient refrigerant concentration is found to exceed a tolerable level.