Driving down carbon emissions for hospital


23 August 2022

A Norwegian hospital has upgraded to an environmentally friendly CO₂ based HVAC-R system using technology from Invertek Drives.

Sinop Technoblock, a specialist refrigeration company in Norway, was appointed to undertake the work at St Olav Hospital in Trondheim to reduce carbon footprint and target significant energy savings. The project includes a laboratory, an on-site hotel and a canteen, which all have numerous cold rooms.

The retrofit incorporated Reftronix CO₂ controllers for packs and cold rooms and Invertek Optidrive Eco VFDs for the compressors. The combination of controllers and VFDs ensures the precise control of the complete refrigeration process as well as remote access to live data, alarms and settings.

The Optidrive VFDs accurately control the speed of the compressors depending on the temperature required and other conditions. This data is picked up by the controller which communicates with each of the drives.

Optimising the speed of each of the compressors motors makes them more energy efficient than the conventional start/stop used in HFC refrigerant systems.

Kjell Robert Overlev, founder of Sinop Technoblock, said: “To go with Reftronix and Invertek Drives was really a very easy decision. Their solutions and full integration with the inverters set them miles ahead of the alternatives.”

A total of 10 400V Optidrive Eco VFDs have been used. These include four 2.2kW, four 1.2KW, one 5.5kW and one 11kW.

The VFDs are connected via a Modbus communication link to the controllers. This means configuration of the drives can be undertaken through the Reftronix controller online portal. The page also allows the status and live data to be available remotely via the cloud.

The controller is capable of measuring temperatures and pressure, calculating optimal performance, adjusting the speed of the compressor through the Optidrive VF and adjusting the opening of electronic valves and the speed of the fan.

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Any alarm or trip warnings are also highlighted via the web page.

Henrik Christensen, general manager at Reftronix, said the combination of their controller and the VFD ensured the refrigeration system was as accurate and efficient as it possibly could be.

“We’ve worked with Invertek for a number of years and this has proved the right decision for us. They have the right inverter for the global HVACR-R industry, a fact proven by the large number of global compressors manufacturers who have endorsed their products,” he said.

“The new refrigeration systems at St Olav Hospital are a great demonstration of how CO2 HVAC-R systems are not only helping reduce energy use and creating greater efficiencies, but are supporting the work in reducing harmful emissions and climate change.”

Invertek Drives, based in Welshpool, Powys, has also developed a VFD dedicated to BLDC compressors, CDUs and heat pumps. Coolvert is aimed at OEMs who want a compact and highly efficient drive. It can work with any controller and can be incorporated in systems where there is limited space, such as fridges and refrigeration systems used in supermarkets.

More details about the Optidrive Eco and Coolvert products can be found at www.invertekdrives.com

Details of the Reftronix controller can be found at www.reftronix.com