Brookfield DW-25W518 -25°C Laboratory Low-Temperature Storage Freezer

Overview

The Brookfield DW-25W518 is a purpose-engineered horizontal low-temperature storage freezer designed for reliable, stable preservation of temperature-sensitive biological materials—including vaccines, reagents, serum samples, and diagnostic kits—in clinical laboratories, blood banks, and public health facilities. Operating within a precisely regulated range of –10 °C to –25 °C, the unit employs direct-cooling architecture with an optimized evaporator layout on the inner cabinet wall to accelerate thermal equilibration and minimize temperature recovery time after door openings. Its microprocessor-controlled refrigeration system regulates compressor cycling via real-time feedback from an NTC thermistor sensor, delivering consistent thermal performance with ±0.5 °C uniformity across the storage chamber under standard ambient conditions (climate class N: 16–32 °C). The absence of chlorofluorocarbons in both refrigerant (R134a or equivalent) and insulation foam aligns with international environmental directives including the Montreal Protocol and EU F-Gas Regulation.

Key Features

• Stable temperature control: Electronic thermostat with 1 °C minimum setpoint resolution and LCD digital display showing real-time internal temperature to 0.1 °C precision.
• Integrated safety alarm system: Simultaneous audible tone and flashing LED indicators activate upon detection of over-temperature excursion (exceeding user-defined upper limit), mains power interruption, or thermistor sensor failure.
• Secure access management: Mechanically latched single foamed door with built-in lock prevents unauthorized access—critical for vaccine integrity and chain-of-custody compliance in WHO-prequalified cold chain environments.
• Energy-efficient design: Optimized heat exchange geometry and ≥80 mm thick CFC-free polyurethane insulation reduce thermal load and sustain low operational power draw (110 W nominal).
• Robust cabinet construction: Exterior coated steel shell provides corrosion resistance; interior embossed aluminum lining ensures chemical compatibility, ease of cleaning, and structural rigidity under repeated thermal cycling.
• Regulatory-ready configuration: Certified to China Compulsory Certification (CCC) standards and registered as a Class II medical device by the National Medical Products Administration (NMPA), supporting audit readiness for GLP-aligned quality systems.

Sample Compatibility & Compliance

The DW-25W518 accommodates standard laboratory storage formats—including stacked plastic or aluminum sample boxes (up to 518 L net volume), multi-tier shelving configurations, and upright vial racks—without compromising airflow distribution. Its manual defrost cycle avoids water accumulation risks associated with auto-defrost systems, preserving long-term stability for moisture-sensitive biologics. While not classified as an ultra-low-temperature (ULT) freezer (i.e., < –40 °C), this model meets WHO Technical Report Series No. 961 Annex 9 requirements for secondary cold chain storage of freeze-dried vaccines and thermostable formulations. It supports documentation traceability through its password-protected display interface and built-in start-up delay protection—features aligned with ISO 13485:2016 clause 7.5.10 (Control of monitoring and measuring equipment) and ICH Q5C stability testing guidance for intermediate storage conditions.

Software & Data Management

This model operates without embedded data logging or network connectivity. All operational parameters—including current temperature, setpoint, alarm status, and lock engagement—are accessible locally via the front-panel LCD. For institutions requiring electronic recordkeeping, external validation-grade temperature monitors (e.g., compliant with ASTM E2810 or ISO 14644-3) may be deployed inside the chamber using the optional calibration port (not supplied). The unit’s alarm logic conforms to basic functional safety principles defined in IEC 61508, with fail-safe behavior ensuring alarm activation during sensor disconnection or power loss. Password protection on the display prevents inadvertent parameter changes—a prerequisite for controlled environment qualification under GxP frameworks.

Applications

• Vaccine storage at district-level immunization centers where –20 °C stability is required for lyophilized measles-rubella (MR) and oral polio vaccine (OPV) formulations.
• Intermediate-term storage of clinical trial biospecimens prior to transfer to –80 °C ULT freezers or liquid nitrogen vapor phase units.
• Quality control laboratories maintaining reference standards for ELISA kits, PCR master mixes, and monoclonal antibody preparations.
• Pharmaceutical distribution hubs fulfilling national regulatory mandates for cold chain continuity between manufacturing sites and regional depots.
• Academic research labs conducting enzyme kinetics or protein crystallization studies requiring reproducible sub-zero incubation environments.

FAQ

What is the recommended ambient operating environment for this freezer?
The unit is rated for climate class N (16–32 °C ambient temperature) per IEC 60068-2-1/2. Installation in poorly ventilated rooms or near heat sources may impair condenser efficiency and increase energy consumption.
Does the DW-25W518 support remote monitoring or Ethernet connectivity?
No. This is a standalone unit with no RS-485, USB, or Wi-Fi interfaces. Integration with building management systems requires third-party wired temperature transmitters and relay modules.
Can the internal temperature uniformity be validated per ISO/IEC 17025?
Yes—using accredited external probes placed at nine standardized locations (per ISO 14644-3 Annex B), though the unit itself does not provide automated mapping reports.
Is the door lock compatible with padlocks or keycard access systems?
No. The integrated mechanical latch accepts only the supplied key; retrofitting is not supported due to structural integrity constraints.
How often should manual defrosting be performed?
Defrost frequency depends on usage patterns and ambient humidity. Under typical lab conditions (<60% RH), defrosting every 3–6 months maintains optimal evaporator performance and minimizes frost bridging.