How Do Ultra Low Temperature Freezers Work?
How ULT Freezers Work: A Muli-cycle System
Ultra low temperature freezers work by using a multi-compressor system to achieve temperatures as low as -86°C (-123°F). Through a process of compression, condensation, expansion, and evaporation of their refrigerants, a ULT can create an environment of extreme cold. Here’s a closer look into the process.
Compressors and Refrigerants: The Journey of Cooling a ULT
Ultra low temperatures are created through a journey that refrigerants take through powerful compressors. As two different, independent refrigerants pass through separate compressor chambers, they travel through high and low temperature refrigeration loops. As they travel, they undergo a series of thermodynamic processes that help create the arctic environment in the ULT chamber. Of these processes, the heat exchange between the two refrigerants is crucial. This exchange supercools the evaporator coils to produce sub-zero temperatures. A ULT’s cascade-design compressors not only maintain this arctic environment, but also enable the freezer to recover quickly from door openings during research.
ULTs also have highly insulated inner chambers to lock in cold air. This specialized insulation together with their powerful compressors allow ULT freezers to maintain extreme levels of cold. In a nutshell, refrigerants and compressors work together with the laws of science to cycle refrigerants into sub-zero cooling.
Understanding How ULTs Work: A Real Life Analogy to Break it Down
Understanding how a ULT freezer works, beyond just knowing it gets cold, gives you confidence that your valuable samples are genuinely secure. We know you want to focus on your science, and not the uncertainties of inadequate equipment. As mentioned above, the core principle that differentiates a ULT freezer from a conventional freezer is that ULTs use multiple compressors and cooling cycles to reach extreme levels of cold. Regular freezers just have one.
To make things simpler, let’s give a real-world analogy. As an illustration, this would look like trying to cool a room to freezing temperatures with just one small air conditioner. No surprise—it simply wouldn’t work. In the same way, reaching and maintaining temperatures down to -86°C requires a multi-stage approach, cooling the air multiple times to reach ultra low temperatures. In the AC example, imagine we took that same room and heavily insulated it. Then we swapped out one AC unit for several powerful blast freezers that cycled the cold air continuously. Suddenly, reaching freezing temperatures is possible. ULT freezers use a similar principle. By employing specialized insulation and multiple compressors designed for extreme cooling, they can achieve their artic state.
What Other Features are Important to a ULT’s Performance?
When considering how a ULT works, the core lies in the power of the compressor system as we outlined above. But other features also contribute to a ULT’s function and performance. These features are important too, especially if you’re looking to purchase a ULT. Ask yourself what refrigerants does a ULT use? How much energy is it consuming? How easy are the controls to navigate?
At ABS we use natural, hydrocarbon refrigerants to power our ULTs to decrease our Global Warming Potential and eliminate our Ozone Layer depletion. Our cutting-edge variable speed compressors (VSCs) use significantly less energy than their older counterparts and have been documented to extend a ULT’s lifespan. And on top of that, our ABS ULT Freezers are equipped with our own custom touchscreens, designed by our engineers to make data logging, charting, and daily use as easy as a few taps. The inner workings of a ULT may be complex, but controlling them doesn’t have to be. We’ve got you covered.
Want to learn more about ULTs? Explore our ULT freezer selection at ABS or reach out to our friendly customer service team at 1-843-821-8010 Option #3 or customerservice@horizonscientific.com.
Technical Writer and Marketing Editor
Christine works as a Technical Writer for Standex Scientific. She holds a B.A. in Creative Writing and has used her writing expertise in various companies from engineering firms to non-profits.