High impact energy conservation measures for chemistry labs in the tropics

Danielle Griego, Research Associate and Project Lead, Energy Research Institute @ NTU
Bing Cai , Section Head, Assistant Manager, Office of Development & Facility Management

A team from the Energy Research Institute @ NTU (ERI@N) and Office of Development and Facilities Management (ODFM) at NTU in Singapore introduced a campus-wide energy reduction initiative at the end of 2011. As part of the initiative, the team outlined monthly and annual energy consumption for each facility (for the first time), and identified that energy consumption is largely driven by research laboratories. The School of Physical Mathematical Science (SPMS), (combination of chemistry/physics labs) was identified as the highest energy consuming facility on campus, with nearly 18% of the total campus energy demand. As a result, ODFM and ERI@N are focusing on energy conservation measures for the chemistry block at SPMS which has 100% fresh air requirements and a high density of fume hoods. Beyond schedule optimization and temperature adjustments activities, the first two on-going studies at this site are a research based laboratory sub-metering study and a practical method to optimize exhaust plumes for deep energy savings.

The sub-metering project is a detailed study to continuously monitor disaggregated energy consumption allocated to lighting, equipment, air conditioning and mechanical ventilation along with other key performance metrics. The study is applied to one laboratory wing (1100 m2) which is representative of 6 lab wings within the chemistry block. This space is served by a single air handling unit (100% fresh air, 24/7 operation) and has 64 fume hoods. The objectives of the study are to a.) Benchmark and characterize energy consumption in chemistry labs located in the tropics and b.) Identify areas of greatest energy savings potential and c.) Serve as a demonstration site for various energy efficiency measures such as fume hood ventilation controls and demand response strategies. The study is of particular interest since no such data or research has been performed for laboratory facilities in Singapore or the tropics.

The exhaust plume optimization study at SPMS is identified by ODFM as an immediate high impact energy saving measure with minimal retrofit investment. All high plume exhaust fans are constant volume. There are eight-3 fan systems which operate as 2 duty, 1 standby (design air flow rate 20,000 CMH/fan) and four-4 fan systems which operate as 3 duty, 1 stand (design air flow rate 13,333 CMH/fan). The exhaust air volume from the laboratory spaces is consistently lower than design system capacities. Therefore ODFM is investigating the potential to turn down one exhaust plume fan, and possibly two from the 4 fan systems during off peak hours. The estimated energy savings for reduced fan power is 2,264,000 kWh/yr or nearly 10% total annual energy consumption at SPMS.

Biographies:

Danielle Griego has worked with the Energy Research Institute @ NTU in Singapore for roughly 2 years in the Sustainable Building Technologies Team as research associate and project lead. In this position, Danielle manages several projects under the NTU campus wide sustainability initiative including the laboratory sub-metering demonstration project and a demand control ventilation study. Danielle is also leading the initiative to form the I2SL Chapter-Singapore. Prior to her position at ERI@N, Danielle worked with the energy service company, EATON's EMC Engineers in Boulder, Colorado. She earned a bachelor's of science in Architectural Engineering and a Master's of Science in the Civil Engineering, Building Systems Program both from the University of Colorado at Boulder.

Mr Cai Bing has nearly 10 years of professional experience in the field of mechanical engineering and roughly 8 years of experience in water and wastewater engineering. For the past 5 years he has worked with the Office of Development and Facilities Management (ODFM) at NTU and is currently the ACMV Section Head and assistant manager. Mr Cai Bing manages and supervises the maintenance & operations for the NTU campus chiller plant network and also for the NTU campus BAS network system. Furthermore, he manages the maintenance operation for all ACMV system throughout NTU campus. He holds a Bachelor of Engineering in Water and Wastewater from WuHan University of Technology in China and a Graduate diploma in Construction management and a Master's of Science in International Construction Management from the Nanyang Technological University. Cai Bing is also a certified energy manager and certified Green Mark Facility Manager.

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