A Guide to Selecting an Ultra-Low Temperature Freezers
What Are Ultra-Low Freezers Used For?
Ultra-Low Temperature Freezers provide secure storage for high-value samples that need to stick around for a while. So their selection and continued operation must be done carefully. Here we’ll take a look at things to consider when buying a -80 freezer for your lab.
Ultra-Low Temp Chest Freezer vs Upright ULT Freezers
A chest freezer is more efficient than an upright, it’s less work for the compressor, and more cold air is retained in the chamber due to gravity. However, the design takes up more floor space and is harder to keep organized. A Chest ULT is ideal for bulky items but when it comes to smaller samples this may not be the best option.
Upright Ultra-low freezers feature more organization opportunities by using rack-based systems to sort and hold items. When selecting a rack system though it’s important to get properly fitting racks to make sure you’re not losing precious inches. Proper fit is also key to making sure the air continues to flow throughout the cabinet for faster recovery and better uniformity.
Insulation is also a factor in not only performance but also the storage to footprint ratio. Typically insulation is either conventional foamed in place or vacuum insulation panels can be used. VIP insulation like those found in Sanyo and PHCbi Ult Freezers, is thinner than their counterparts, using the lower thermal conductivity properties of air in a vacuum to guard against temperature fluctuations.
This does create more storage capacity, however, if the panel develops a crack from too frequent openings, then the partial vacuum can be compromised and temperature loss could occur. So when deciding, consider the frequency of access you’ll have and weigh it against your storage capacity needs.
Energy Efficiency in a ULT Freezer
A larger freezer uses energy more efficiently than a smaller freezer. Depending on your lab, this may or may not be an important consideration for you. If you’re in a private lab you may not be concerned about it, but in a university setting with shared spaces, this could be a factor. Paying attention to the power consumption per vial is a good measurement to help you find the best fit.
Some ULT freezers feature twin compressors. Depending on the setup, these are either high and low stage compressors where the high stage cools the lower stage, or it’s a backup system. Ultra-low temperature freezers that sport these systems tend to be more costly, however, they are more energy-efficient in the long run.
Temperature and Event Reporting in an Ultra-Low Freezer
Keeping track of your lab freezers’ performance not only helps you stay on top of potential risks but may also be a requirement of your work. If your samples involve blood plasma, vaccines, and pharmaceuticals of frozen foods it’s important to know the integrity of the temperature levels through continued monitoring and to be able to provide documentation to specific agencies.
Users of ULTs have a few options, sometimes more than one is required depending on the situation. Most modern ULT freezers have digital control panels that automatically record performance that can be exported to a USB thumb drive, other options include a chart recorder that documents 7 days of performance including temperature shifts and openings. Back up systems such as wifi alarms hooked up to remote alarm contacts, external temperature probes, and dataloggers,
When Might It Be Time To Replace A Freezer?
If you’ve had your ultra-low freezer for more than 10 years in continuous operation, then the time may have come to replace it. A good indication is when recovery takes hours instead of minutes, evaluate the current pull-down rate vs the manufacturer’s specifications, pay attention to where the measurement is taken from (top, middle bottom), and compare. If it’s taking a very long time, that’s not something that can be fixed and you should look into a replacement. Another good indicator is if it requires repair, how much is that repair going to cost? If the cost gets you halfway to a new freezer then a new
Newer models are going to be more energy-efficient thanks to improved refrigerant and compressor technology. A compressor-free system such as the Stirling Ultracold SU780XLE operates with a free-piston engine, saving not only energy but also taking up less space than a traditional system. In either case, a newer -80 Freezer can lead to a decrease in operating costs for both power consumption and HVAC needs.
Other Considerations When Buying An Ultra-Low Freezer
Other considerations to maximize the life and value of your ULT freezer once you have it include making sure not to use the ULT freezer as a blast freezer. If you need to freeze something quickly then a dedicated blast freezer will be more efficient and will avoid strain on an Ultra-Low Temperature Freezer. Items going into an Ultra Low freezer should already be frozen to help avoid temperature dips and stress on the compressor.
Setting a regular maintenance routine including removing frost build-up, and cleaning gaskets and filters. And while you CAN mute alarms on your freezer, don’t ignore them, address the issue such as maintenance, or power failures as soon as you can.
The freezer should be in a room where the ambient temperature can be controlled and the unit can be properly ventilated. A sweltering room in the middle of summer is not going to be good for your ULT freezer that’s also generating its own heat, compounding the problem. If you are going to have more than one, making sure there’s enough space between them for proper ventilation is also critical. If available, check the tolerated ambient temperature range and make sure you’re going to be able to meet it.
Final Thoughts
An Ultra-Low freezer houses some of your highest value items. Making sure that you have the right tool to meet the job isn’t just a nice to have, it’s critical. Every ULT freezer we receive is put through the same rigorous testing and inspection. We check for integrity, and pull-down rates, make sure they’re operating within the manufactures performance standards and provide validation so you have a clear picture of what you’re buying. We work with our customers to find the right fit, and level of security to meet their needs and budget. Buying a verified gently used ULT Freezer is a great way to get more features and storage without blowing the budget.
Connect with us today and let us help you find the right Ultra-Low Freezer for your lab!
