Energy savings by night cut energy bill by 12%
Simply by managing its building and its services more efficiently Clerical Medical in Clevedon is saving £20 000 a year in energy costs. A team from Climate Controls Europe analysed the energy usage of the building and recommended a number of changes. Chris Kelsall, energy surveyor with the HBOS Group (of which Clerical Medical is a part) explains, ‘Following an energy survey of the site, the team implemented a number of energy-saving recommendations. On completion, a 30% reduction in the overnight standing load was achieved, with an overall saving of 12%, equivalent to £20 000, with an investment payback of less than two years.’ Chris Norburn of Climate Controls Europe explains that the building’s energy usage was monitored and recorded so that energy use before and after changes could be compared. He says, ‘An unusually high level of energy appeared to be used during the night, so we carried out a night survey to understand what was happening in the building at different times and the reasons behind the high levels of consumption. The results of this audit formed the basis of a number of changes, for example: • fan-coil units that were previous coming on at 0230 h and off at 2200 h were reset to 0600 to 2100 h, with only a 5-minute preheat time; • running times for office air-handling units were similarly changed from 0430 and 0200 h to 0545 to 2000 h, with no preheat;period. • logic and setpoint faults on AHU heating pumps were adjusted and fixed to prevent pumps running continuously. Chris Norburn says, ‘We were able to match the controls to the occupancy of the building to ensure that they worked on demand rather than for more random time frames. We also took into account possible environmental considerations and adjusted the building-management system to take this into account.’ The £20 000 annual energy savings equate to a reduction in carbon-dioxide emissions of 109 t a year.