The manufacturing process of a Temperature Humidity Test Chamber (THC) is a systematic, multi-stage workflow that integrates mechanical engineering, electrical control, thermal dynamics, and precision assembly. It focuses on ensuring the chamber’s core performance—such as temperature/humidity control accuracy, environmental uniformity, and operational safety—while meeting industry-specific standards (e.g., ISO 10281, ASTM D4359). Below is a detailed breakdown of the key manufacturing stages:

This stage lays the foundation for the chamber’s performance and reliability, requiring close collaboration between design engineers, material specialists, and quality teams.

• Requirements Analysis: First, engineers clarify the chamber’s target specifications based on customer needs or industry standards, including:
  • Temperature range ( -70°C to +180°C for standard models, -196°C for cryogenic models).
  • Humidity range ( 10%–98% RH, or ≤5% RH for low-humidity versions).
  • Chamber volume (benchtop 50L, floor-standing 1000L, or walk-in 50m³).
  • Special functions ( UV irradiation, salt spray, vacuum).
• 3D Modeling & Thermal Simulation: Using software like SolidWorks, AutoCAD, or ANSYS, engineers design the chamber’s structure (outer shell, inner liner, insulation layer) and simulate:
  • Thermal uniformity: Ensuring no “hot spots” or “cold zones” via airflow duct design (e.g., optimizing fan placement and baffle angles).
  • Heat/cold retention: Calculating the thickness of insulation materials (e.g., polyurethane foam, vacuum panels) to minimize energy loss.
  • Humidity distribution: Simulating water vapor diffusion to avoid condensation on sample surfaces.
• Control System Design: Develop the PLC (Programmable Logic Controller) program and HMI (Human-Machine Interface) to support multi-segment test cycles, data logging, and safety alarms.

Only high-performance, corrosion-resistant, and temperature-stable materials are selected to withstand extreme test environments:

Key subsystems (e.g., refrigeration, humidification, air circulation) are pre-assembled and tested individually to ensure they meet performance benchmarks before integration.

The refrigeration system is responsible for cooling the chamber to low temperatures (down to -196°C for cryogenic models) and works with heaters to adjust temperature dynamically.

• Compressor Assembly: Select scroll compressors (for standard models) or cascade compressors (for ultra-low temperatures) and assemble them with copper tubes (brazed via nitrogen protection to avoid oxide buildup in tubes).
• Condenser & Evaporator Production:
  • Condenser: Bend copper tubes into a finned structure (aluminum fins for heat dissipation) and pressure-test (1.5x working pressure) to detect leaks.
  • Evaporator: For low-temperature models, use spiral copper tubes to enhance heat exchange efficiency; coat with anti-frost materials to prevent ice buildup.
• Refrigerant Charging: Inject the precise amount of refrigerant (e.g., R410A) into the closed circuit and test for leaks using a helium leak detector (leak rate ≤1×10⁻⁹ Pa·m³/s).

This system controls humidity by adding or removing water vapor:

• Humidifier Production: For steam humidifiers, fabricate stainless steel heating tubes (with anti-scale coatings) and assemble them into a water tank. Test steam output rate (e.g., 2kg/h for 1000L chambers) and ensure uniform vapor distribution.
• Dehumidifier Production: Use refrigeration dehumidifiers (cooling coils to condense moisture) or desiccant dehumidifiers (silica gel for low-humidity models). Test dehumidification efficiency (e.g., reducing humidity from 98% to 10% RH in ≤1h).

Uniform airflow is essential for consistent temperature/humidity across the chamber:

• Fan & Duct Production: Mold ABS plastic ducts (or stainless steel for high temperatures) into a “circular airflow” design. Install brushless fans and adjust blade angles via simulation to ensure airflow velocity (0.5–1.5 m/s) and uniformity (temperature difference ≤±2°C).
• Baffle Installation: Attach adjustable stainless steel baffles to ducts to redirect airflow and eliminate dead zones (e.g., near the chamber door or