How to Choose an Ultra-Low Temperature Freezer for Your Lab

When you need to safely store biological samples, vaccines, or sensitive materials, an ultra-low temperature (ULT) freezer is essential. They can provide lower temperatures than household refrigerators and standard freezers.

However, there is no standard ULT freezer that perfectly matches all applications. Temperature range, compressor design, energy usage, and safety features all affect the performance of the equipment. This article explains the factors to consider before purchasing an ultra-low temperature freezer.

What is an Ultra-Low Temperature Freezer?

Unlike low-temperature freezers, ultra-low temperature (ULT) freezers usually use cascade refrigeration. They can achieve lower temperatures, typically ranging from -40°C to -86°C. They are better suited for long-term storage of temperature-sensitive biological samples or materials, such as stem cells, vaccines, or bone marrow. Therefore, you often see them in biological laboratories and hospitals.

How to Choose an Ultra-Low Temperature Freezer for Your Lab - Biological Samples Storage（images 1）

How to Choose an Ultra-Low Temperature Freezer for Your Lab - Cascade refrigeration（images 2）

Why Do You Need a ULT Freezer?

If your work involves biological samples that can lose activity or affect experimental data when briefly exposed to warm environments, a reliable ULT freezer can store them safely.

Although ULT freezers are not designed for frequent door openings, they can minimize temperature fluctuations in the chamber when warm air enters and quickly restore cooling.

Some users may think -40°C is sufficient, but after using a -80°C freezer, you will notice the difference. Clearly, materials and samples stored in a ULT freezer face a lower risk of contamination.

How to Choose a ULT Freezer?

Temperature Range

The temperature range of a ULT freezer can be customized. Standard models typically reach -80°C, while high-performance units can reach -86°C or even below -100°C.

A lower temperature does not always mean a better freezer. You must consider the temperature requirements of the materials you want to store. Some samples need -70°C, while others are fine at -60°C. A wider temperature range offers more flexibility but also comes at a higher cost because the low-temperature refrigeration technology is more advanced and complex.

Capacity and Storage Layout

You should determine the size of the freezer based on the volume of samples to be stored and the available space for the ULT freezer. Some small upright freezers can easily fit under a counter or on a table, while large freezers require dedicated space.

Additionally, overcrowding inside the chamber can block airflow, causing uneven temperatures. So, consider the number of items you need to store.

Shelves, racks, and inner doors are also important. Well-designed interiors reduce frost buildup and help maintain uniform temperature distribution.

Cooling System Type

Most ULT freezers use dual-compressor cascade systems, but the design varies by brand. Reliable compressors, high-quality refrigerants, and efficient heat exchangers ensure long-term stable operation.

Temperature Uniformity and Recovery

Temperature uniformity refers to how evenly the temperature is distributed inside the chamber. Recovery refers to how quickly the temperature returns to normal after opening the door. Well-designed airflow systems allow ULT freezers to maintain temperature variations within ±1°C, even when fully loaded.

If you frequently open and close the freezer door, prioritize fast recovery performance. This helps avoid thermal shock and protects temperature-sensitive samples.

Noise and Heat Emission

Freezers release heat while removing energy from the chamber. In small rooms, this extra heat can reduce comfort and increase air-conditioning costs. Therefore, leave sufficient ventilation space around the installation site.

Modern ULT freezers often feature better insulation and low-noise compressor designs. Typical operating noise is about 50 to 55 decibels, quiet enough for most laboratory environments.

Safety and Monitoring

To ensure the safety of samples, equipment, and personnel, each freezer is equipped with safety devices. For example, temperature alarms notify staff if the temperature deviates from the set value. Battery backup systems protect samples during short power outages. Door locks prevent unauthorized access.

In addition, most ULT freezers have remote monitoring features, allowing you to check the operational status on a computer or smartphone in real time.

After-Sales Service and Support

Maintenance is essential to ensure the longevity of the equipment. Consumable parts need regular replacement, and minor faults require technician service. This all depends on supplier support. A responsive and technically capable service team can provide installation, commissioning, and long-term maintenance solutions, saving you a lot of trouble.

LNEYA’s Ultra-Low Temperature Solutions

LNEYA provides reliable low-temperature and ultra-low temperature freezers to laboratories, pharmaceutical companies, and industrial users worldwide. Our engineers can tailor the best solution according to your application requirements. We ensure each unit is tested under working conditions and extreme conditions so that it perfectly matches your needs upon delivery.

If you plan to upgrade or install a new ultra-low temperature freezer, feel free to contact us.

Let us know your requirements