Flakt Woods energy-efficient ventilation for university
A reversible hat pump and a thermal wheel are key features of Flakt Woods ventilation system installed as part of the refurbishment of the Arundel Building at Sheffield Hallam University. The system can supply up to 2.5 m3/s of conditioning air into a VAV (variable air volume) system and incorporates inverter-driven compressors. It replaces a natural-ventilation system.
A ReCooler heat-pump unit is incorporated into an eQ air-handling unit instead of a separate wet heating coil or DX coil. This approach makes for a neat and tidy package that offers COPs much higher than the alternatives.
The ventilation system is designed so that each of the five floors is divided into six zones with ducting serving individual VAV boxes with temperature and CO2 control.
Lee Allen, senior building-services manager at the university, explains, ‘The refurbishment has been divided into two phases, with the installation of the ventilation system in phase one. From the outset, we decided to take a new approach, incorporating highly efficient mechanical-ventilation equipment alongside cross-flow ventilation with new opening windows. This has been designed to allow the centralised ventilation system to be optimised for mixed-mode conditions.’
The ReCooler HP unit provides heating and cooling from a built-in reversible heat pump and thermal wheel.
Russ Oliver, managing director of Flakt Woods, explains, ‘This installation is the first of two projects that we have carried out for Sheffield Hallam University that incorporates the ReCooler HP unit.’