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Plug Loads in Laboratories including ULT Freezers

Tue, 07/10/2018 - 13:40 -- MrGreen

On May 31, the California Energy Commission held a webinar on Emerging Technologies: Energy Savings in Plug Loads, co-sponsored by the Emerging Technologies Coordinating Council (ETCC). Although the presentation on Mobile Efficiency for Plug Load Devices by Vojin Zivojnovic of AGGIOS, Inc. was cancelled due to technical difficulties, the team of Allison Paradise of My Green Lab and Alison Farmer of kW Engineering did discuss their research on laboratory equipment, focusing on ultra-low temperature (ULT) freezers, and the efforts to promote ENERGY STAR standards for energy-efficient laboratory equipment.

According to their research, laboratories consume five times more energy than office spaces. Of that, more than one-fifth comes from plug loads. The laboratory space in California, including that for academia, biotech, hospitals, and non-profits, is estimated at 116 million square feet, and the annual consumption associated with the laboratory equipment alone is in the range of 0.8 – 3.2 TWh per year. Laboratory plug load categories include freezers, refrigerators, centrifuges, water baths, incubators, and autoclaves among others. Fume hoods are treated separately from plug loads and categorized with HVAC electricity consumption. Of the plug load types, ULT (-80°C) freezers are the top energy-consuming category and thus the focus of the study.

The study has evaluated energy consumption and temperature performance of freezers per the ENERGY STAR test method, analyzed performance in the field, compiled baseline energy values, assessed the market, and looked at the impact of energy-efficient ULT freezers on HVAC systems. For freezer sizes in the most popular range of 21 -28 cubic feet, energy consumption for the installed base (1.1 kWh/ft3/day) is notably higher than that for standard-efficiency models (0.693 kWh/ft3/day ) and even greater when compared to energy-efficient models (0.324 kWh/ft3/day). To help offset the higher purchase price of energy-efficient ULT freezers, there are rebate programs for qualified freezers with the ENERGY STAR label. Replacing existing ULT freezers with high-efficiency models can realize a potential savings of 41 million kWh per year.

Webinar slides can be found here.

Version 1.1 of the ENERGY STAR Program Requirements for Laboratory Grade Refrigerators and Freezers, in effect since 12/21/2016, can be found here.