Toshiba develops complete system for refrigerant leaks
The Toshiba team at Toshiba Carrier UK has developed a system for detecting and containing refrigerant leaks in single- and multi-split (VRF) air-conditioning systems. The technique is said to be so effective that buildings with this system qualify for additional BREEAM points. There are three versions covering applications from an individual unit serving a single room to fully distributed VRF systems serving multi-storey buildings — with potentially hundreds of items of equipment.
The smallest system uses wall-mounted sensors in the protected area to sample room air and detect refrigerant gas. In the event of a leak, it activates a visible and audible alarm and shuts down the system.
The second option is for larger schemes, such as distributed VRF installations. The reduced low-side pressure resulting from loss of charge is used to trigger an alarm and automatically shut down the system.
The third option works in a similar manner but also isolates the liquid and discharge lines and performs a full system pump-down, after which the suction line is isolated.
This third system also uses additional temperature sensors to detect increased discharge temperatures associated with very gradual refrigerant loss. It can therefore monitor a sudden major loss of charge as well as slow leaks that might otherwise be missed.