The positive air displacement system, developed by Pennine Environmental Services Limited, is specifically designed to provide a draught free temperature controlled environment in food processing factories and utilises a mix of internal and filtered external air to maximise the potential of ‘free’ environmental cooling and energy efficiency.
The system creates a ‘bath’ of cold air, maintained at between 8 to 10 deg C, from floor level up to head height, together with a combination of fresh and recycled air to maximise efficiency and minimise running costs. Due to the efficient use of air it requires less equipment and lower fan power for increased efficiency and lower capital costs. Utilising ‘free’ environmental cooling to maximise energy efficiency, the positive displacement system is ideal for production areas with high occupancy and ceilings 3.5 m or higher. The system is ideal for applications where hygiene procedures require dehumidification and reheat to reduce the moisture content of large quantities of air.
Air displacement terminals are placed at various locations in the production area to evenly distribute the cold air. Terminals are manufactured in stainless steel and are fully accessible for cleaning. The system operates by feeding air through ducting to the air handling unit, fitted into the roof void, which houses the air circulation fan, filters and cooling coils. Cold air is then discharged through ducting to the individual displacement terminals.
Major benefits of the Pennine system include increased energy efficiency, compared to normal grille systems, and as the system can circulate less air it can work on wider temperature differences. The return air can be allowed to rise in excess of room temperature, thereby reducing the total air volume and allowing greater use of ambient air, providing a significant saving in energy costs.