Hanuo GDH-0506 High-Precision Low-Temperature Circulating Chiller

Overview

The Hanuo GDH-0506 High-Precision Low-Temperature Circulating Chiller is an integrated temperature control system engineered for laboratory-scale thermal management of analytical instruments, reaction vessels, and material testing setups. It operates on a closed-loop refrigeration principle using a hermetically sealed compressor, R134a refrigerant, and forced-air heat rejection—enabling stable, continuous operation across a broad working range from −5 °C to 100 °C. The unit employs a dual-stage thermal regulation architecture: primary temperature stabilization occurs within the stainless-steel reservoir via PID-controlled refrigeration and electric heating; secondary precision is achieved through real-time feedback from a high-stability Pt100 sensor immersed directly in the circulating fluid. This design ensures ±0.01 °C temperature stability (typical) under steady-state conditions with a digital resolution of 0.001 °C—meeting requirements for applications demanding traceable thermal reproducibility, including viscometry calibration, UV-Vis spectrophotometer cell temperature control, and DSC reference stage conditioning.

Key Features

• Hermetically sealed rotary compressor with dual protection circuitry (overheat and overcurrent), ensuring long-term reliability and minimizing refrigerant leakage risk.
• Full stainless-steel reservoir and work surface (AISI 304), resistant to corrosion from aqueous, ethylene glycol, or ethanol-based heat transfer fluids.
• High-efficiency centrifugal circulation pump delivering up to 6 L/min at 0.07 MPa pressure—capable of supporting external jacketed reactors, condensers, or calorimeters up to 15 m total head.
• XMT-series digital PID controller with intuitive keypad interface, real-time setpoint ramping, and programmable hold functions.
• Compact horizontal footprint (W250 × D200 × H150 mm bath cavity) optimized for integration beneath fume hoods or inside instrument enclosures.
• Standard RS232 communication port for remote monitoring and basic parameter logging (optional Modbus RTU upgrade available).

Sample Compatibility & Compliance

The GDH-0506 accommodates standard laboratory fluids—including deionized water, 30% aqueous ethylene glycol, and low-viscosity silicone oils—within its chemically inert stainless-steel bath and wetted components. Its temperature stability profile complies with ASTM E1137/E1137M (Standard Specification for Temperature-Indicating Devices) for Class B accuracy in controlled environments. While not certified to ISO/IEC 17025 or GLP as a standalone metrological device, the chiller supports GxP-aligned workflows when used as ancillary equipment: temperature setpoints and actual bath readings are digitally recorded, and the system permits manual audit trail generation via timestamped operator logs. All electrical components meet IEC 61010-1 safety standards for laboratory equipment.

Software & Data Management

The GDH-0506 operates autonomously via its embedded XMT controller without requiring host software. For laboratories implementing centralized environmental monitoring, the RS232 interface enables integration with third-party SCADA platforms or custom Python/LabVIEW scripts for periodic polling of current temperature, setpoint, and status flags (e.g., compressor active, alarm condition). Data export is ASCII-formatted and time-stamped at user-defined intervals (1–60 s). No proprietary drivers or cloud services are required. The unit does not store historical data internally; persistent logging must be managed externally. FDA 21 CFR Part 11 compliance is not inherent but can be achieved through validated external acquisition systems that enforce electronic signature, audit trail, and data integrity protocols.

Applications

• Thermal conditioning of UV-Vis, FTIR, and fluorescence spectrophotometer sample compartments to reduce baseline drift during kinetic assays.
• Cooling and temperature stabilization of rotary evaporator condensers and vacuum manifolds during solvent recovery.
• Supplying regulated coolant to jacketed glass reactors (≤5 L volume) for exothermic synthesis control.
• Calibration support for rotational viscometers and rheometers requiring precise bath temperature referencing per ASTM D2196 and ISO 3219.
• Stabilizing detector housings in chromatography systems (HPLC, GC) where ambient fluctuations impact retention time reproducibility.
• Low-temperature pre-conditioning of polymer samples prior to tensile or DMA testing per ASTM D638 and ISO 527.

FAQ

What heat transfer fluids are compatible with the GDH-0506?
Deionized water, 20–40% aqueous ethylene glycol solutions, and low-viscosity silicone oils (e.g., Dow Corning 200 Fluid, 5–10 cSt) are recommended. Avoid chlorinated solvents, strong acids/bases, or fluids with flash points below 35 °C.

Can the unit maintain −5 °C continuously in a 30 °C ambient environment?
Yes—provided the heat load does not exceed 300 W and adequate ventilation (≥150 mm clearance on all sides) is maintained around the air-cooled condenser.

Is the bath opening large enough to accommodate a standard 1-inch optical cell holder?
Yes—the 180 mm × 140 mm opening allows vertical insertion of most cuvette holders, immersion probes, and small reactor adapters.

Does the chiller include a fluid level sensor or dry-run protection?
No. Operators must manually verify fluid volume before startup. Running the pump dry may cause irreversible damage to the impeller and seal assembly.

What is the expected service interval for the compressor and refrigerant circuit?
Under typical lab usage (8 h/day, moderate ambient), the sealed compressor requires no scheduled maintenance for ≥15,000 operating hours. Refrigerant recharge is only necessary if verified leakage exceeds 10% capacity (detectable via pressure drop and reduced cooling performance).