Case study | Urban Sciences Building Comparison of energy by end use TM54 v POE CIBSE TM54 compared to POE data 60 After one year in operation, the energy use of USB was compared with the predicted energy use from CIBSE TM54: Evaluating Operational Energy Performance of Buildings at the Design Stage to see how the building performed against predicted energy use. 50 kWh.m-2 per year 40 TM54 Scenario 1 Year 1 POE 30 20 10 With the POE data in place, the design team can offer targeted advice to the university to try to achieve a DEC C rating for next year, with an aspiration to aim for a DEC B the following year. From our current position, a DEC C rating would require a total CO2 reduction of 6.5%, which should be achievable, and a DEC B would require a 33.5% reduction in total CO2 emissions, Wines says. One year after occupation, a Building Use Studies (BUS) survey was done, and the results compared with the BUS dataset and against the three university buildings where the USBs occupants were based previously. The USB building scores better than the BUS benchmark mean and BUS-scale midpoint for all criteria, with the exception Hu m id ifi ca tio n Co ol in g Fa ns Pu m p he s at /co re nt jec ro tio l/ n He at in g Ot he re qu ip m en Do t m es tic ho tw at er Ca te rin g Sm all po we r Se rv er ro om s Lif ts Lig ht in g 0 of BUS benchmark mean for noise. Some survey comments suggest the USBs open-plan spaces, which allow it to be easily reconfigured, are not universally popular: The offices were supposed to encourage collaboration, but they stifle it because some people want absolute silence, was one comment. Others have praised the design: This areas large, open layout makes it easy to find and communicate face to face with my colleagues and the atmosphere is conducive to working. The survey reported that 71% of users in the USB find its design makes it easier to collaborate and 76% said it was simple to find a workspace that suited their activity. Dowson believes USB will score better in subsequent surveys because, in the first year of occupation, snagging was taking place, which affected comfort and productivity. Further, directly in front of the USB is an active construction site, so this impacted on some of the noise scores, he adds. With two years of soft landings to run, and the buildings 4,000 sensors, there is plenty of scope to fine-tune the USBs systems and to optimise its already impressive energy performance still further. CJ CIBSE TM54 predicationed energy use compared to POE data from the Urban Sciences Building TM54 predicted (kWh.m-2 per year) USB actual Difference (%) (kWh.m-2 per year) Explanation Lighting 9.7 15.2 +56% Increased use resulting from increased out-of-hours and weekend use. Also lights being left on in large areas where presence detection was overridden Lifts 1.2 1.3 +4% Original TM54 assessment did not include allowance for weekend use Small power 48.9 25.2 -48% The difference assumed to be because of students using laptop batteries in communal areas, use of lower power, higher efficiency ICT, and building may not be fully up to occupancy Server rooms 13.1 15.7 +20% TM54 based on RFI response. University to review if load has increased from original assessment and profile Catering 16.0 7.9 -51% At the time of the original assessment, the intensity of use was unknown, so simple benchmarks for example, kWh per meal were used Other equipment 5.4 5.2 -4% This includes doors curtains, PV, building meters and sensors, and external lighting DHW 6.5 10.0 +54% Input from DHW heat pump was less than estimated, so a larger proportion has been provided via the boiler-supplied LTHW system, and energy provided by gas has increased Heating 10.7 18.2 +70% Model assumed a winter heating temperature of 21C. The user controls on site have full functionality to allow users to select temperatures up to 24C in winter. Small power gains may also be a factor Fans 13.0 11.0 -15% Probably a result of additional demand control functionality incorporated into the BMS Pumps, controls and heat rejection 22.6 27.4 +21% A fault in the first year meant the main heating and cooling pumps were set to run 24/7, rather than shut down at night Cooling 10.6 16.4 +55% Actual temperature data shows summer temperatures warmer than average. Also, occupants have the ability to set room minimum below the 22C used in the assessment Humidification 1.3 1.8 +44% Summer temperatures warmer than normal, requiring increased cooling of fresh air and resulting in dehumidification 40 December 2018 www.cibsejournal.com CIBSE Dec18 pp36-40 Urban Science centre.indd 40 23/11/2018 16:07