Cool-Therm has launched a system for actively controlling the sound output from air conditioning chillers.
Called Dynamic Noise control (DNC), Cool-Therm claims it guarantees a chiller will not exceed a pre-set noise limit, irrespective of ambient conditions.
The company say it is designed to overcome the increasingly stringent requirements on noise produced by building services plant, imposed by local authorities, planners and end users, which can affect the siting and – in many cases – viability of chiller installations.
Ken Strong, managing director of Cool-Therm, says: “Sensitivity over noise produced by externally-sited air conditioning plant is now a hot issue in many city centres and built-up areas. Dynamic Noise Control addresses the problem of noise produced by air conditioning chillers, and offers a cost-effective solution.”
The Dynamic Noise Control system constantly monitors sound levels produced by a chiller. If a pre-set noise limit is reached, it actively controls and adapts chiller operation to reduce sound levels – while maintaining chiller output, to ensure cooling to the building is maintained.
The system consists of a microphone and sound processing system mounted on the chiller or at a suitable remote location from the chiller (say, in the direction of residential buildings), and is linked and integrated into the chiller controls.
Chiller noise levels are continuously measured and recorded on the chiller display. Readings can also be routed to an external Building Management system via Modbus, for real-time monitoring.
The maximum permitted noise level can be activated or deactivated for specific time-windows during the day, as in a time clock, to provide “noise assurance” for particularly sensitive times, for example at night.
When in noise-limiting mode, if chiller sound output reaches the set-point the DNC will automatically adapt and balance the speed control of (primarily) fans and (secondarily) the compressor, as needed, to keep the noise level below the set-point.
The algorithm controlling the operation of DNC is designed to deliver the predetermined sound levels as the priority, while reducing as far as possible the impact on cooling capacity (second priority) and energy performance (third priority).
Cool-Therm claim that tests show that, in practice, sound levels can be delivered in most cases with only a tiny sacrifice in energy efficiency and no reduction in cooling capacity.
It has been developed as an accessory that can be factory-fitted or retrofitted to Turbomiser chillers, or indeed any chiller which has a compatible control system.