Sample storage freezer LDF-21

for vaccinesfor biopharmaceutical applicationsfor clinical laboratories

Product Overview
The LDF-21 portable ultra-low temperature freezer provides compact, transportable ULT storage with a 25 L chamber and an operating range of +18°C to -45°C. Using a free-piston Stirling cooling engine with helium working gas and compatible low-GWP refrigerant options, the unit delivers stable temperature control (target ±1°C), low vibration and low steady-state power consumption for clinical, pharmaceutical and field applications.

Features

• Stirling cooling: Free-piston Stirling cooler offering compressor-free ultra-low temperature operation.
• Wide temperature range: Adjustable from +18°C to -45°C with precise control.
• Rapid pull-down: Approximately 1.5 hours from 25°C to -45°C.
• Temperature stability: Cabinet stability target ±1°C.
• Low power consumption: Steady-state ~30 W (ambient 25°C); typical average ~40 W noted.
• Quiet, low vibration: Noise level <50 dB and reduced vibration by Stirling design.
• Portable design: 25 L chamber, net weight 17.5 kg, compatible with AC and DC power for lab, vehicle and field use.
• Environmentally conscious: Helium working gas and options for low-GWP refrigerant.
• Gravity-driven thermosiphon: Reliable heat transport with low maintenance.
• Instrumentation & security: Digital temperature display, one RTD (PT100 Class B) control sensor (precision ±0.3), integrated temperature alarm (setpoint ±10°C) and lockable lid.
• Maintenance: Manual defrost.

Applications

• Clinical laboratories
  Transport and short-term storage of clinical specimens, blood products and diagnostic materials under controlled ultra-low temperatures.
• Biotechnology and research
  Preservation of DNA/RNA, enzymes, proteins, cell cultures and other temperature-sensitive biological samples.
• Pharmaceuticals & vaccines
  Cold-chain storage and transport for vaccines, biologics and temperature-sensitive pharmaceutical products.
• Hospitals & blood banks
  Interdepartmental and off-site transport of critical medical samples and blood components.
• Field research & environmental sampling
  Portable preservation for samples collected in remote locations.
• Emergency medical services
  Reliable cold storage for urgent transport of biological specimens and temperature-sensitive materials.

Technical specifications

• Product type: Portable ultra-low temperature freezer
• Storage volume: 25 L
• Temperature range: +18°C to -45°C
• Cooling technology: Free-piston Stirling cooler
• Refrigerant / working gas: Helium (He); compatible low-GWP refrigerant options
• Heat transport system: Gravity-driven thermosiphon
• Display: Digital temperature display
• Control sensor: One RTD (PT100 Class B), precision ±0.3
• Operating environment: 5°C to 35°C, ≤80% RH, altitude ≤2000 m
• Net weight: 17.5 kg
• Pull-down performance: 25°C to -45°C in ~1.5 hours
• Temperature stability: Target ±1°C
• Steady-state energy consumption: ~30 W (ambient 25°C)
• Noise level: <50 dB
• Defrost method: Manual
• Temperature alarm: Setpoint ±10°C
• Power supply: 100–240 V AC, 50/60 Hz; 12–24 V DC
• Maximum power consumption: 100 W (0.5 A @ 220 V, 0.45 A @ 240 V)
• Insulation: Vacuum insulated panels with polyurethane foam
• Security: Lockable lid
• Internal dimensions (L × W × D): 300 × 250 × 300 mm
• External dimensions (L × W × D): 616 × 392 × 455 mm
• Shipping dimensions (L × W × D): 710 × 480 × 533 mm
• Shipping weight: 21 kg