Lab refrigerators and freezers are similar in construction to household units, and come in a variety of temperature ranges, shapes and sizes.
Freezer and refrigeration options fall into four general temperature categories: +4ºC refrigerators for chromatography supplies, blood storage, and pharmaceuticals; -20ºC (and below) freezers for enzymes and biochemicals; -30ºC to -40ºC for biological samples, and -80°C freezers for long-term storage and stability. Units range in size from under-counter systems as small as 3.6 cu. ft., to standalone chests as large as 70 cu. ft.
After considering temperature capabilities, capacity and footprint, choosing among lab refrigerators and freezers often reduces to secondary or subjective criteria. Eye-level controls, mechanisms to prevent door freezing and/or vacuum pressure build-up, space-saving insulation, automated data recording, alarms, digital temperature control, rapid temperature recovery after door openings, temperature uniformity throughout the box, and condition monitoring are differentiators. However, purchase decisions often come down to brand name recognition, perceived reliability, price and availability.
Tamper-proof temperature logging and recording are desirable features for regulated industries and those called on to testify in court. Thermo Fisher Scientific (Marietta, OH) plans to offer a wireless recording/ logging option in 2010, but companies have been slow to adopt such equipment due to difficulties in changing established SOPs. The traditional chart recorder is still the industry standard for temperature monitoring. However, most industries are moving toward electronic temperature monitoring.
One notable development in refrigeration has been the emergence of cold storage to support vaccine work, particularly for H1N1 influenza vaccine storage. H1N1 vaccine is stored within a narrow temperature range (35ºF to 46ºF), and health agencies mandate twice-daily temperature measurements.
Many labs use household kitchen refrigerators to store very low-risk laboratory materials, but these units are designed for low-traffic use and lack the precise temperature control and refrigeration capabilities of labdesigned units. Several vendors have nevertheless made a business of refurbishing and retrofitting home-appliance cooling chests for labs. Common upgrades include alarms, controllers, door locks and special shelving.
Energy efficiency has become a key driver in refrigerator/freezer purchase decisions. Many vendors have been working with the U.S. Environmental Protection Agency to establish industry-wide Energy Star standards for lab refrigerators and freezers, which surprisingly do not yet exist. Beginning in late 2008, vendors began submitting energy efficiency and performance data to EPA, from which the agency will eventually issue guidelines for the coveted Energy Star designation. Energy consumption for “always-on” appliances is a serious concern for large organizations like pharmaceutical companies and universities.
“Due to their heavy usage, lab refrigerators and freezers will never be as energy efficient as units purchased for the home,” said Gordon Shields, director for cold storage at Thermo Fisher Scientific. “The key is to reduce overall energy usage while maintaining performance.”
- Lab refrigerators: Choose from 12 to 72 cubic feet capacities
- Chromatography refrigerators: designed for laboratory research and storage for hospitals, clinics, and R&D
- Lab freezers: Great for samples requiring -12 to -30°C (10.4 to -22°F) temperatures
- Allows for increased energy savings and efficiency through new-andimproved heat exchanger and refrigeration system
- Provides a minimized footprint for high-density storage
- Showcases a state-of-the-art preservation system using Cool Safe compressors that are specifically designed for low temperature applications
DHS-9RF Refrigerator/Freezer Combo
- Exterior w x d x h 23.5” x 24” x 79.5” 59 x 61 x 202 (cm)
- Interior w x d x h 19” x 15” x 35” (R) 17” x 15” x 27” (F)
- Features dial temperature control
- Has a temperature range of 4°C (R) to -25°C (F)
- One-year domestic warranty
- Provides low temperature cooling to either -40ºC or -80ºC
- Does not require expendable liquid nitrogen and the associated pumping, re-filling, and storage challenges posed by a cryogenic liquid
- Immerses samples into a well-circulated, cold liquid bath