OK STW-2 Walk-in Environmental Test Chamber (Temperature Only)

Overview

The OK STW-2 Walk-in Environmental Test Chamber is an industrial-grade, large-volume temperature test system engineered for system-level environmental validation under controlled thermal conditions. Unlike benchtop or upright chambers, the STW-2 functions as a fully accessible, room-scale test environment—designed to accommodate full-size vehicles, battery energy storage systems (BESS), avionics racks, server cabinets, or multi-unit production batches. Its core operational principle relies on precision-controlled convective air circulation within a thermally isolated enclosure, utilizing cascade refrigeration and high-power resistive heating to achieve stable, repeatable temperature profiles across wide ranges—from ambient up to +85°C (optional) and down to –70°C. The chamber’s modular architecture supports field assembly and future expansion, making it suitable for permanent installation in R&D labs, quality assurance centers, and production validation facilities where spatial scale and thermal fidelity are non-negotiable requirements.

Key Features

• Modular high-density polyurethane (PU) insulated panel construction with galvanized steel or stainless-steel cladding—providing thermal resistance (R-value) compliant with ISO 13788 and ASTM C518 standards.
• Structural steel framework designed to maintain dimensional stability under repeated thermal cycling and mechanical load, supporting ceiling-mounted instrumentation and internal cable management rails.
• Large walk-in door with double-glazed observation window, electrically heated anti-frost film, pneumatic sealing gasket, and safety interlock that halts operation upon unauthorized opening.
• Cascade refrigeration system featuring separate high-temperature and low-temperature compressor stages—enabling reliable operation at sub-zero setpoints without refrigerant freezing or oil migration issues.
• Multi-point air distribution network with backward-curved centrifugal fans and calibrated diffusers—ensuring ≤ ±3°C temperature uniformity (per IEC 60068-3-5) across the entire working volume.
• PLC-based control system with 7-inch color touchscreen HMI, supporting up to 99 programmable segments per test profile, real-time deviation alarms, and configurable event logging (time-stamped, user-ID tagged).

Sample Compatibility & Compliance

The STW-2 accommodates physically large or thermally active test articles—including electric vehicle powertrains, photovoltaic inverters, telecom base station enclosures, and aerospace subsystems—with internal dimensions fully customizable (minimum 1 m³; scalable to >100 m³). Optional feedthrough ports (NPT or flanged) allow uninterrupted signal, power, and fluid line access while maintaining thermal integrity. The system complies with essential environmental testing standards including ISO 16750-4 (road vehicles), MIL-STD-810H Method 501.7/502.7 (temperature storage and operation), and IEC 60068-2-1 (cold) / IEC 60068-2-2 (dry heat). All controllers meet IEC 61508 SIL2 functional safety requirements and support optional 21 CFR Part 11-compliant electronic signatures and audit trails for regulated industries.

Software & Data Management

The embedded controller runs OK’s proprietary EnviroLogic™ firmware, offering intuitive drag-and-drop profile programming, real-time trend visualization, and automatic report generation (PDF/CSV). Data is stored locally on encrypted SD card and simultaneously mirrored via Ethernet to a central SCADA or LIMS platform. Optional cloud gateway enables secure remote access through TLS 1.2–encrypted HTTPS, with role-based permissions (operator, engineer, QA auditor). All logged parameters—including chamber setpoint, actual temperature (multi-sensor averaged), compressor discharge pressure, and fan speed—are timestamped with millisecond resolution and retain full traceability for GLP/GMP audits.

Applications

• Automotive: Whole-vehicle cold-start validation, HVAC performance mapping, battery thermal management system (BTMS) characterization, and ADAS sensor functionality testing across extreme ambient conditions.
• Energy Storage: Cycle-life evaluation of grid-scale lithium-ion BESS cabinets under dynamic temperature profiles simulating outdoor deployment in desert or arctic climates.
• Aerospace & Defense: Environmental screening of UAV airframes, mission-critical avionics bays, and satellite payload modules per DO-160G Section 4.
• Data Infrastructure: Thermal stress testing of 19-inch rack-mounted servers, edge computing nodes, and liquid-cooled GPU clusters under sustained high-load conditions.
• Industrial Electronics: Batch reliability screening (HASS/HALT pre-screening) of industrial PLCs, motor drives, and power converters prior to field deployment.

FAQ

What is the minimum recommended internal volume for personnel entry during operation?
A minimum clear internal dimension of 1,800 mm (W) × 2,000 mm (D) × 2,200 mm (H) is required to comply with OSHA 1910.146 confined space entry guidelines when operators need to access the chamber during test execution.
Can the chamber be integrated with external power supplies or data acquisition systems?
Yes—standard configurations include four NPT 1/2″ feedthroughs (two on side walls, two on rear wall), rated for IP65 ingress protection and capable of accommodating up to 35 mm² power cables or shielded twisted-pair signal lines.
Is humidity control available as an option?
Humidity functionality is not included in the STW-2 base model; however, the OK-STH-2H variant adds steam-based humidification and dehumidification modules, enabling combined temperature/humidity testing per IEC 60068-2-30.
How is temperature uniformity validated and documented?
Uniformity verification follows IEC 60068-3-5 Annex B: nine PT100 sensors are placed on a 3×3 grid at mid-height, recording data over 30 minutes at three setpoints (–40°C, 25°C, +70°C); final report includes max deviation, standard deviation, and spatial gradient analysis.
What electrical supply specifications are required for installation?
Standard configuration requires a dedicated 380 VAC ±10%, 50 Hz, 3-phase + PE supply with minimum 63 A circuit breaker; voltage drop across supply lines must remain below 2% under full refrigeration load.