Memmert ULT Freezer ULT240, ultra-low-temperature freezer

Memmert ULT Freezer ULT240 represents a highly advanced cryogenic system solution for the long-term storage and preservation of biological and pharmaceutical samples in biobanks, university research institutions and industrial laboratories. When handling highly sensitive samples such as RNA extracts, protein isolates or primary cell lines, absolute temperature stability is the primary criterion for physically ruling out any structural damage to the integrity of the samples caused by thermal fluctuations. The ultra-low temperature freezer covers a precisely adjustable temperature range from -50 °C to -86 °C and, thanks to its advanced system architecture, ensures full compliance with strict SOPs (Standard Operating Procedures). For procurement professionals in the pharmaceutical industry, this model offers the necessary process reliability and investment validity, as it has been specifically designed for demanding, energy-optimised continuous operation under GLP and GMP conditions.

Cascade cooling and inverter-controlled compressor dynamics

The refrigeration heart of the Memmert ULT240 ULT freezer is based on a high-performance system comprising two compressors connected in cascade. This cascade configuration is physically necessary to bridge the extreme temperature differences between the laboratory environment and the interior of the chamber in a way that is gentle on materials and thermodynamically efficient. The first stage uses the refrigerant R455A, whilst the second stage is operated with R170 to reliably achieve the ultra-low target temperatures. Through the integration of inverter-controlled compressors, the system dynamically adjusts its cooling capacity in real time to match the actual cooling demand. When the door is opened, the electronic control system compensates for the influx of heat and moisture by increasing the compressor speed. In steady-state operation, however, the system runs in the energy-optimised partial-load range, which not only drastically reduces energy consumption but also minimises mechanical wear and extends the service life.

Material-science barrier function and ergonomics

The structural system boundary of the Memmert ULT240 ULT freezer is defined by a high-quality housing made of textured stainless steel and an interior made of pure stainless steel. This choice of materials guarantees outstanding corrosion resistance against aggressive disinfectants and prevents cross-contamination in multi-user settings at universities. To minimise uncontrolled entropy exchange when accessing the stored cryoboxes, the interior features an intelligent 4-compartment layout, protected by two separate stainless steel inner doors. This thermal barrier ensures that, when accessing samples, only a small portion of the 244-litre internal volume is exposed to ambient air. A mechanical door lock protects the valuable contents from unauthorised access, whilst an integrated pressure relief vent with a diameter of 26 mm allows the outer door to be reopened immediately after closing by physically equalising the resulting internal vacuum.

Cyber security and Lab 4.0 documentation

For scientific quality management, the Memmert ULT240 ULT freezer a sophisticated digital control concept via a 7-inch touchscreen integrated into the outer door, which is positioned ergonomically. Temperature is measured using high-precision Pt1000 resistance sensors, which enable a setting accuracy of 0.1 °C. The cybernetic safety concept includes both visual and audible alarm systems in the event of temperature deviations or an open door, triggered via door-open detection. An integrated backup battery ensures that monitoring and alarm functions are fully maintained even in the event of a total power failure, and that valuable sample batches remain protected. Via modern communication interfaces such as Ethernet LAN and USB, the ULT freezer can be seamlessly integrated into digital Laboratory Information Management Systems (LIMS) and monitored remotely, ensuring complete documentation of the cold chain for audits.

Technical details

Thermodynamics & Refrigeration Technology

• Cooling system: Cascade system with two compressors
• Compressor control: Inverter-controlled for optimised performance
• Refrigerant, stage 1: R455A
• Refrigerant, stage 2: R170
• Condenser: Air-cooled
• Temperature range: -50 °C to -86 °C

Metrology & Control Engineering

• Control unit: Ergonomic 7-inch touchscreen, integrated into the outer door
• Setting accuracy: 0.1 °C
• Temperature sensor: Pt1000
• Interfaces: Ethernet LAN, USB
• Safety features: Visual and audible alarm, door-open detection
• Power failure protection: Back-up battery for continuous alarm and monitoring

Construction & dimensions

• Internal volume: 244 litres
• Internal dimensions (W x H x D): 450 x 1111 x 489 mm
• Cabinet dimensions (W x H x D): 700 x 1832 x 738 mm
• Cabinet material: Textured stainless steel
• Interior material: Stainless steel
• Max. Load capacity per unit: 280 kg
• Max. Load per shelf: 140 kg
• Maximum capacity (50 mm boxes): 162 units

Infrastructure & Logistics

• Door construction: Insulated stainless steel external door with mechanical lock
• Pressure equalisation: Side feed-through / pressure relief opening with a diameter of 26 mm
• Installation: Can be moved and locked in place on sturdy swivel castors
• Net weight: 245 kg
• Gross weight (including packaging): 310 kg
• Statistical commodity code: 8418 40 20
• Certifications: CE-certified

Contents of delivery

• 1 x Memmert ULT240 ULT freezer base unit
• 2 x stainless steel internal doors for thermal segmentation
• 3 x stainless steel shelves (height-adjustable)
• 1 x Integrated backup battery for power failure protection
• 1 x Integrated castor unit (movable and lockable)
• 1 x operating instructions

Important note: Storage racks and cryoboxes for the systematic storage of samples inside the chamber are not included as standard and must be configured to suit the specific application.

Custom requirements & accessories

To make the most of the 244-litre interior of the Memmert ULT240 ULT freezer and to minimise convective heat exchange when accessing samples, the use of bespoke stainless steel racks and cryoboxes makes good physical sense. The system can accommodate up to 162 standard 50 mm boxes. For the vertical storage of heavy sample batches (max. 140 kg per shelf), we recommend an even weight distribution to protect the fibre structures of the pull-out shelves. For GMP-relevant applications, we are happy to assist you with manufacturer-compliant qualification (IQ/OQ). Please make use of our procurement service to select your cryogenic infrastructure.