BAM FM Ltd provides facility management services to Wharfedale Hospital, including mechanical and electrical maintenance. The modern, 76-bed in and outpatient facility in West Yorkshire is operated by Leeds teaching hospital NHS Trust. It provides a mix of primary and secondary healthcare services, including surgery via two dedicated on-site Operating Theatres. Working with Wharfedale Hospital, BAM FM came up with a new solution to their Heating, Ventilation and Air Conditioning management, reducing electricity use by 28%.
The hospital facilities are operational on weekdays only, however the Heating, Ventilation and Air Conditioning (HVAC) system in the two Operating Theatres was on constantly, whether or not the theatre was actually in use. This was due to concerns over airborne contamination and infection control.
Continuous operation however, was very wasteful of energy, especially because the system is designed to provide very high volumes of specially conditioned air via High Efficiency Particulate Air (HEPA) filtration.
Continuous use of the HVAC system was inefficient
An experimental study at the Freiburg University Hospital in 2003 had concluded that shutting down Operating Theatre ventilation during off-duty periods was hygienically safe, provided the HVAC systems had been restarted for some time before surgery procedures began. It also concluded that low microbial contamination was only required during the time between incision and suture, i.e. microbial protection was not required from the instant the patient entered the Operating Theatre.
Based on these findings, BAM FM worked with the infection prevention team to propose a new, more energy efficient, management system. The Operating Theatres’ HVAC systems would be completely turned off at night and during weekends. Additionally, motion sensors would be fitted in the rooms so when a theatre had been unoccupied for one hour ventilation would be reduced to 50%, providing a further reduction in consumption.
BAM FM also programmed a “quick restart” sequence into the Building Management System (BMS) so an Operating Theatre could be fully operational in the case of an emergency.
BAM FM proposed a new, more energy
efficient management system
The introduction of the new HVAC management system saw an average electricity saving of 28% compared to the 24/7 operations, and is now the standard setting for the Operating Theatres. The changes result in a yearly cost saving of over 13,600 kWh of electricity and over six tons of annual CO₂ emissions.
The new management system saves 6 tonnes of CO2 annually