An ultra low temperature freezer or ULT freezer is specifically designed to store temperature-sensitive items at freezing temperatures often below 80 degrees celsius. They are essential for the safe storage of vaccines, some medicines, DNA samples, bone marrow, tissue samples and other biological materials. Ultra low temperature freezers have features to ensure they maintain these extremely low temperatures. These freezers are used in clinical environments such as hospitals, clinics, medical laboratories and research facilities and operate between -60°C and -86°C.
How Does an Ultra Low Temperature Freezer Work?
Ultra low temperature freezers work on the same principle as regular freezers by removing heat instead of adding cold. Ultra-low temperature (ULT) freezers utilise either cascade or dual (twin) refrigeration systems. Both are capable of reaching ultra low temperatures, yet their design philosophy is different. Dual or twin guard systems feature two separate refrigeration circuits, each with their own compressor, condenser and evaporator. If one of the compressors should fail, the other automatically takes over to maintain the freezer’s ultra low temperature. The dual system prioritises redundant security and ensures exceptional temperature stability even during maintenance or unexpected failures of a single component.
Cascade Refrigeration System
The cascade refrigeration system uses multiple circuits with different refrigerants to achieve lower temperatures than a regular freezer. This multi staged approach allows for extreme temperature control and stability which sensitive samples and vaccines need.
- Primary temperature cycle: The primary temperature cycle cools and condenses the refrigerant for the low temperature second stage. This high temperature cycle uses a compressor to remove heat from the second stage refrigerant, causing it to turn into a liquid which is known as the ‘cascade’ between the two stages. The liquid absorbs through the expansion valve and evaporates, absorbing the heat.
- Secondary temperature cycle: This cycle is the low temperature cycle which cools the space to be refrigerated and sends the absorbed heat to the high temperature cycle condenser via heat transfer.
- Heat transfer: This is the component that links the primary and secondary cycle and is the key to achieving ultra low temperatures. The heat exchanger is needed as the condenser for the high temperature cycle and evaporator for the low temperature cycle. It is the medium that allows the high temperature refrigerant to give up the heat to the low temperature refrigerant which is the cascade and cooling effect from one stage to the next.
The Dual Refrigeration System
Vacc-Safe DualGuard ULT freezer can be used for the storage and protection of temperature sensitive samples and valuable pharmaceutical products. Using two independent refrigeration systems, if one system fails, the other can maintain the freezer’s temperature uniformly in the -80°C range. Dual cooling systems offer the highest level of protection to ensure continued operation.
The Key Components of Ultra Low Temperature Freezers are:
- Advanced refrigeration: The dual refrigeration system is an advanced refrigeration method with an additional backup plan in the event of a system failure. The cascade refrigeration system is another technology that provides these freezers the ability to achieve and maintain ultra low temperatures.
- Superior insulation: Ultra low temperature freezers have superior insulation which is necessary to maintain extremely low temperatures. Using advanced technologies these freezers are able to keep samples and vaccines at temperatures as low as -80°C which is essential for their safety and viability. Insulation features include vacuum insulation panels which have better thermal performance than other materials, multiple layers of insulation, enhanced sealing and extra inner doors to minimise the amount of cold air escaping. The walls of the freezer are also often significantly thicker than those of standard refrigeration for additional insulation.
- Compressor: This is the core of an ultra low temperature freezers cooling system. It is responsible for compressing and moving refrigerant gas to remove heat from the internal compartment of the unit. The compressor is essential for maintaining the ultra low temperature. Vacc-Safe offers a 5 year warranty on selected ultra low temperature freezers if the compressor fails and needs to be replaced.
- Monitoring and alarms: Ultra low temperature freezers have external and internal alarms and monitors to protect the temperature sensitive medications and biological samples. Options for alarms range from simple visual systems to complex setups that send sms and email alerts with temperature variations. Internal alarms are built into the freezer and trigger things like high or low temperature, power failure, door ajar, sensor error or low battery. Optional external alarms can be connected to a separate monitoring system which sends alerts outside the physical freezer about things like high or low temperatures, door openings or power failures.
- Backup battery: A backup battery is an optional feature that provides temporary power to an ultra low temperature freezer during a power outage. They protect the samples during an unexpected event by ensuring continuous operation and preventing cold chain breaches. Types of backup systems are uninterruptible power supply (UPS) or CO2 or liquid nitrogen backup systems. The UPS uses a battery to power the ultra low temperature freezer during a power failure.
Types of Ultra Low Temperature Freezers
The two main types of ultra low temperature freezers are upright and chest freezers. Each differs in their size, design and efficiency.
Vacc-Safe Upright ULT Freezer:
These ultra low temperature freezers have a front door similar to a standard refrigerator. They are vertical freezers designed for storing sensitive materials that need to be kept at extremely low temperatures. This makes samples and medications easy to access using shelves, compartments and drawers. They are essential in medical and clinical environments and the most common type of ultra low temperature freezer. Features of an upright ultra low temperature freezer include easy access, larger capacity and ideal for areas where space is limited.
- VS-86L108 108 Litre – From $7,999.00
- VS-86L358 358 Litre – From $9,999.00
- VS-86L458S 458 Litre – From $12,999.00
- VS-86L568S 568 Litre – From $14,999.00
- VS-86L708S 718 Litre – From $16,999.00
- VS-86L818S 838 Litre – From $17,999.00
- VS-86L580BS 580 Litre – From $18,999.00
- VS-86L720BS 720 Litre – From $19,999.00
Features
- Heated pressure equalisation port
- Multi layer silicon sealing structure
- Slim cabinet design (VS-86L358 and VS-86L458)
- Twin refrigeration systems (on 568 litre models and above)
- VIP plus insulation
Additional features
- Built in battery backup for the controller
- Lockable
- Single LED display (for the 108 and 358 models)
- Touchscreen controller (for the Vacc-Safe ULTFreezer 458L, 568L, 718L, 838L)
- USB data recorder
Vacc-Safe ULT Chest Freezer
These ultra low temperature freezers are designed as a horizontal opening chest with a top lid, rather than one or two front opening doors. These freezers have a horizontal configuration and are ideal for long term storage of biological samples, vaccines and some medications.
An advantage of chest freezers is that when opening the unit less cold air is released and the internal temperature remains more stable. Disadvantages can be that accessing contents is more difficult and users need to lean in and over the unit while lifting or lowering items in or out.
- VS-60W100 – 100 Litre – From $3,999.00
- VS-86W100 – 100 Litre – $4,999.00
- VS-86W485 – 485 Litre – $9,999.00
- VS-60W485 – 485 Litre – From $5,999.00
Features
- Microcomputer temperature control system
- Medical Freezers for -60 to -25°C and -60 to -86°C
Additional features
- Lockable
- Single LED display
Uses for Ultra Low Temperature Freezers
Ultra low temperature freezers are used for storing temperature sensitive materials like vaccines, dna, cells and tissues. They preserve viability and prevent degradation as the faster something freezes the smaller the crystals that form causing less damage to cell walls.. They are used in a wide range of medical and scientific applications. These include:
- Pharmaceutical storage: Ultra low temperature freezers are used in pharmacies to store temperature sensitive vaccines, medications and other pharmaceuticals that require long term storage. These may include biological samples like plasma and other medications that require extreme cold and stable environments to maintain their integrity. Pharmacy ultra low temperature freezers prevent molecular degradation and other chemical reactions that could make the medications and samples ineffective or unusable.
- Biomedical research: Hospitals, laboratories and research facilities use ultra low temperature freezers for biomedical research. Temperature sensitive biological samples like cells, tissues and enzymes need to be stored in ultra low temperatures to maintain their integrity and viability. They are imperative for research materials like cell lines, patient tissues and genetic material which is crucial for research continuity.
- Cryopreservation: Ultra low temperature freezers are imperative for cryopreservation which is the process of preserving living cells, tissues and other biological products. These materials need to be kept at ultra low temperatures using cryoprotectants and specialised equipment like ultra low temperature freezers. This storage process prevents sample degradation and maintains viability for applications like stem cell storage.
Ultra low temperature freezers are essential pieces of equipment for storing temperature sensitive medications, vaccines and biological samples at extremely low temperatures. They work on the same principle as standard refrigeration but with more efficient cooling techniques such as cascade systems or utilising gases that can obtain much lower temperatures to remove heat. Ideal for pharmacy, medical clinics, hospitals, laboratories and research facilities, there are a variety of ultra low temperature freezers available at Vacc-Safe.
