Toshiba Carrier UK Limited have developed a new approach to detecting and containing refrigerant leaks in air conditioning systems
David Dunn, Toshiba Air Conditioning’s UK commercial director, says: “Our systems are designed from the ground up to minimise and, wherever possible, eliminate the potential for refrigerant loss.”
“The quality of our products and manufacturing processes are second to none, and if installation is carried out correctly there is no reason to expect leakage during normal operation.”
“However, in the real world there will always be the possibility of knocks and bumps onsite and unforeseen circumstances. Our new systems address this and provide a complete solution.”
The new Toshiba system qualifies for additional BREEAM points, significantly boosting their environmental credentials.
There are three versions, covering applications from an individual air conditioning unit serving a single room, up a fully distributed VRF systems serving multi-storey buildings, with potentially hundreds of items of equipment.
The first option (RBC-RD3) uses wall-mounted sensors located within the protected area, connected to a small split or VRF indoor unit. It works by sampling room air and detecting increased levels of refrigerant gas; in the event of a leak, it activates a visible and audible alarm and automatically shuts down the system.
The second option (RBC-RD4) is designed for use with larger air conditioning applications, such as distributed VRF installations. The onboard system works by detecting reduced low-side pressure resulting from loss of charge. In the event of a leak, it triggers an audible and visual signal on the local panel, or remotely if required, and again automatically shuts down the VRF system.
The third option (RBC-RD6) offers the ultimate in fail-safe detection and response. It works by monitoring the low-side system pressure using a Toshiba 0-5 Volt Pressure Sensor installed in the VRF outdoor unit. The sensor data is fed back to a mini-computer located in the control panel.
It also has up to four discharge line temperature sensors, to provide an additional level of system monitoring to support and corroborate data from pressure sensors.
Upon activation, it triggers an audible and visual signal at the panel, and remotely if required. The liquid and discharge pipes are isolated via motorised ball valves, and a full system pump-down is commenced. Pump down duration is controlled via the onboard computer. Upon termination, the suction line is isolated via a third motorised valve.
It is the only refrigerant leak detection system on the market that offers full automatic pump down, to deliver the ultimate fail-safe condition in the event of a leak.
The use of the additional temperature sensors enables the system to detect increased discharge temperatures associated with very gradual refrigerant loss. As a result, it is able to monitor both sudden major loss of charge as well as low level leaks that might otherwise be missed, but could have a significant impact on charge levels and performance over time.
David Dunn said: “Refrigerant containment is one of the central issues facing the industry. Minimising leaks is key to the industry’s reputation for responsible environmental stewardship, and is a vital issue in the current review of F-Gas legislation.”
“There are a lot of partial solutions on the market. Our aim was to deliver a comprehensive solution to refrigerant containment that matched the degree of risk with the appropriate level of security and response. Our new systems offer this, and provide complete peace of mind for end users.”