Some best practices with both refrigerators and freezers include regularly maintaining them by defrosting, cleaning, and attending to the coils and seals. Elimination of old samples is another practice that applies to both types of appliances. Regarding freezers, the most energy-intensive pieces of equipment in most biology labs are the ultra-low temperature (−80°C) variety. A typical unit consumes between 16 and 35 kWh/day. Considering that In general, smaller freezers tend to use more energy per cubic feet than larger freezers if possible, try to buy freezers with larger capacities. In addition, setting the freezer temperature at -70’C instead of -80’C, when permissible, is an important energy-saving practice. Source: labs21
- Raising units’ set points by at least 10°C, saves the equivalent energy of one standard freezer.
- DNA can be stored safely at minus 20 degrees Celsius, in standard freezers, for an energy savings of nearly 75 percent.
- Potential savings of up to 1 megaWatt-hour annually (depending on lab size) with archive practices and alternative storage methods, while making samples safer and more accessible.
- Savings in energy can mean more funds for research.
Tools and Resources
Tools are provided to help you match resources to your laboratory needs. Resources below will help to facilitate:
- Setting freezers, except those storing biological tissue, at -70 C.
- Clearing freezers of potential fire starters and reactive agents.
- Consolidating freezer and refrigerator space to optimize capacity.
- Centralizing freezers, refrigerators, and common access storage.
- Ensuring incubators are not being used as refrigerators
- Surveying refrigerator seals
Setting freezers, except those storing biological tissue, at -70 C.
The following link is an Energy Star PDF that not only defines what types of laboratory refrigerators and freezers there are, but goes into details about each type. It even goes on to set up energy consumption tests and further defines what products require what temperatures ranges during storage. This guide will not only show which type of unit is best, but will also help on how to test the unit itself.
Clearing freezers of potential fire starters and reactive agents.
Virginia Tech University has provided a Chemical Storage and Management page that explains how to properly store potential fire starters and reactive agents. The National Center for Biotechnology Information also has a section (http://www.ncbi.nlm.nih.gov/books/NBK55868/) that describes the management of chemicals and how to properly order, store, share and recycle certain chemicals.
Consolidating freezer and refrigerator space to optimize capacity
Cold space is always at a premium, but to reduce energy use, it should also be used wisely to reduce the need for more freezers or refrigerators. Regularly clean out and organize cold spaces to use them the most efficiently and to more easily locate samples, minimizing time spent with the door open. Consolidate compact freezers/fridges into as few as possible and unplug ones not in use.
- Suggestion: To reduce the storage of old chemicals/reagents always date them when they are received. Chemicals/reagents too old to use should be thrown out or collected for hazard waste pick-up.
- Suggestion: All stored samples should be correctly labeled and easily associated with a researcher/experiment. Any mystery boxes/tubes that are unknown and not useful to anyone and should be discarded.
- Suggestion: When someone leaves the lab, go over the stored samples they leave behind to 1) consolidate into properly labeled boxes/racks, 2) keep only relevant samples.
- Suggestion: Regularly inventory/clean out your freezer/fridge spaces to use them efficiently.
- Suggestion: Use/fill freezers to capacity before purchasing another one.
Ensuring incubators are not being used as refrigerators
Incubators used as refrigerators use more energy than a refrigerator. If you aren’t using an incubator, simply shut it down.
Surveying and maintaining refrigerator seals
Refrigerator seals can make the difference between supplies staying fresh and spoiling. This could also mean extra dollars in the long-run since the refrigerator unit will be forced to consume more energy to keep the interior at the desired temperature. Adding the task, “Survey refrigerator seals” as one of the things to do during an internal audit or adding it to the list of things to do at the end of the quarter may be useful.
- Harvard University In the Spring of 2011, two labs participated in a pilot Freezer Cleanout Program. Each lab cleaned out one –80 freezer and disposed of old samples. The following results were achieved:
- Lab 1: 44 Boxes of Samples Disposed of, providing 2.75 racks of new space
- Lab 2: 67 Boxes of Samples Disposed of, providing 4.2 racks of new space
Works Cited and More Resources
Fume Hood Sash Stickers Increases Laboratory Safety and Efficiency at Minimal Cost:. N.p.: US Department of Energy, Mar. 2012. Pdf.
“Environmental Health & Safety || Section 7I: Laboratory Equipment.” Baylor University. Baylor University, n.d. Web. 16 Sept. 2015. <http://www.baylor.edu/ehs/index.php?id=92739#heating>.
“Indiana University.” Fume Hoods. Indiana University, n.d. Web. 16 Sept. 2015. <http://www.ehs.iu.edu/topics/laboratory-chemical-safety/fume-hood-shut-sash.shtml>.
“Laboratory Energy Efficiency Profiler Tool.” I2SL: Resources. International Institute for Sustainable Laboratories, n.d. Web. 16 Sept. 2015. <http://www.i2sl.org/resources/toolkit/leep.html>.
“Managing Energy Costs in Laboratories.” Business Energy Advisor. E Source Companies, n.d. Web. 16 Sept. 2015. <http://bizenergyadvisor.com/laboratories>
Selvaggio, Frank. Energy Efficiency in Laboratories. N.p.: Schneider Electric, 2013. .pdf.
“Sleep and Hibernation: Frequently Asked Questions.” Windows.microsoft.com. Microsoft, n.d. Web. 16 Sept. 2015. <http://windows.microsoft.com/en-us/windows7/sleep-and-hibernation-frequently-asked-questions>.
“Store Smart.” Conserve Energy. University of California, Davis, n.d. Web. <“Store Smart.” Sustainability. University of California, Davis, n.d. Web. 19 Sept. 2015.>.