Trend Control Systems says that, for many healthcare estates managers, the most effective way to control their energy use could be ‘right under their noses – using building energy management systems (BEMS)’.
For example, London’s Charing Cross Hospital has achieved ‘significant annual gas and electricity savings’ through energy-saving initiatives based on three key ‘rapid payback action strands’ – improved monitoring and optimisation of heating and ventilation using a Trend BEMS, installing variable speed drives (VSDs) on 70 air circulation fans, and steps to reduce the electricity used by lighting. The Hospital recently upgraded its existing Trend BEMS, simultaneously installing energy meters in all main plant rooms, which are now monitored via the BEMS. The resulting data allowed the Estates Department to identify and cut energy wastage ‘substantially’. Trend explains: “While the Hospital operates ‘24/7’, some areas are not used overnight. Using the BEMS, estates staff examined all parts of the buildings, and could then match heating times closely with periods of occupation.” Installing VSDs with high efficiency motors on circulation fans also saved substantial energy. The fans previously operated only at maximum speed, but now the BEMS monitors air circulation demand in each area, and then commands the VSDs to adjust fan motor speeds accordingly. The Trend BEMS is now also controlling the hospital’s cooling towers and main chiller plant. Chillers switch off when the outside air temperature falls below 15°C, and then harness ‘free cooling’ provided by the outside air. The Hospital is aiming ‘to match lighting with needs’. Lighting switches off in many areas when unoccupied, while in others, occupancy sensors activate lights when staff enter. Many lamps have been replaced with ‘intelligent’ light fittings.
