When Helmer Scientific set out to develop our Ultra-Low Temperature Freezers, we started with our customers’ pain points. It is extremely disruptive when an ultra-low freezer fails to work properly – the stored items have to be moved to another freezer, samples could be lost, and there is downtime and expense due to service calls. These are fundamental issues we wanted to address with the design of our product.
The key problem that drives many ultra-low service issues is oil management. What does oil have to do with ultra-low freezers? The compressor, which provides the vital task of moving refrigerant through the copper coils, requires oil to function properly. Oil that sits idle in a -86ºC environment will form clogs that prevent the refrigerant from moving through the system (this phenomenon is called "oil logging"). The clogs produce warm-ups because the refrigerant can't maneuver through the system to cool. These warm-ups result in service calls where the technician turns the unit off and the frozen oil thaws. When the unit is restarted, it seems to be working properly until the oil clumps and freezes again, and the whole cycle repeats itself. Many costly service calls can be attributed to poor oil management.
The best way to eliminate this expensive and counterproductive cycle is by using a freezer that prevents oil logging from happening in the first place. Brian Hoaglan, Low Temperature Products R&D Manager at Helmer Scientific, identified a three step approach. “First, it’s critical to minimize the oil in the evaporator section. Second, oil must be prevented from collecting anywhere. Third, it’s imperative to keep the oil flowing at low temperatures.”
The design of Helmer’s ultra-low freezers follows for each step of this approach, including an advanced method for installing copper routing that prevents pooling and traps.
For users of ultra-low freezers, confidence in how it’s designed and how it performs is important. To learn more about the design of Helmer Scientific Ultra-Low Temperature Freezers, please view our Interactive Demo.
