Toshiba’s new leak detection technology is designed to isolate the incident and enable the susyem to continue functioning as normal, so as to avoid unnecessary downtime
In the event of a refrigerant leak within a building, the conventional approach is to shut down the entire system, which affects the occupants until the source of the leak can be identified and repaired.
However, Toshiba Air Conditioning has launched an advanced version of its refrigerant leak detection and management system, which is designed to isolate the specific section of refrigerant pipework containing the leak, enabling the rest of the system to continue functioning as normal.
While the conventional approach shuts down the entire system in the event of a leak, the new technology means that only the immediate area served by the compromised circuit suffers loss of service.
Toshiba Air Conditioning general manager David Dunn says: “This technology is a major step forward and extremely useful for applications such as hotels and multi-tenanted buildings. It means that, in the unlikely event of a leak, those areas unaffected can continue to function as normal and receive cooling and heating as required. The benefits are obvious.”
Toshiba’s new refrigerant detection and isolation technology uses a number of separate “isolation cells” throughout a building, consisting of an RBC-RD3 refrigerant concentration sensor, a pair of motorised isolation valves, and an RBC-RD7 control box.
The motorised valves are fitted in refrigerant pipework (liquid and gas) outside each conditioned space, the room sensor is located within the space at low level, and the control box is mounted next to the indoor unit.
If the sensor detects refrigerant in the room, it triggers an alarm and an L30 fault code on the indoor unit, detected in turn by a central controller or BMS, and initiating the isolation sequence.
The motorised valves close automatically, effectively isolating the conditioned space from the rest of the system.
At the same time, onsite maintenance staff and service contractors are notified of the alarm status and its location, and can zero-in on the problem to resolve it.
The technology is primarily designed for use with Toshiba VRF systems (SMMS, SMMSi, SHRM, SHRMi, Mini SMMS), but can also be used with split systems.
Toshiba has also developed an improved version of the RBC-RD3 in-room refrigerant concentration sensor. The unit has a recessed design to protect it from accidental damage, and can be fitted into a standard, single electrical back box.
The design of the face-plate can be changed to match the room décor or client specification, particularly important for application in hotels.
The device is recessed into a wall approximately 150 mm from floor level within the conditioned space, and connected to the indoor unit via supplied leads. On detection of a higher-than-normal refrigerant concentration, it shuts down the indoor unit and gives an audible and visual alarm.
Toshiba total refrigerant system: additional benefits
- Air conditioning systems operating on a reduced charge, as a result of an unidentified leak, do not operate at optimum performance, therefore running costs for systems with the correct charge, maintained by the Toshiba protection system, are reduced and optimum performance maintained;
- The system can help extend the working life of major system components, as a slow leak may not be picked up by a standard leak detector or ‘sniffer’;
- It enables rapid and effective refrigerant checks on site, through simple visual inspection, ensuring straightforward compliance with the F-Gas Regulation;
- In the case of accidental damage to pipework, emergency pump-down of the affected circuit renders the system completely safe, quickly and automatically;
- The failsafe monitoring system continues to operate even if the front-of-house computer is turned off. It can even be set to initiate an alarm to inform staff that the operating computer is no longer working;
- It can be equally applied in nursing homes or respite centres, where people may need assistance to evacuate a building in the event of a refrigerant leak. For example, for a vulnerable person asleep in a hotel room, perhaps unable to see or hear standard visual/audible alarms, the system can be connected to shake pads, now used in a growing number of hotels, which wake the sleeper and alert them to the problem.