A compact, cost-effective apparatus for environmental testing of optical component durability

Outdoor optical devices, such as heliostat mirrors used in concentrating solar power systems, suffer mechanical and optical degradation from sand, dust, rain, and thermal cycling. Existing test chambers are typically large, costly, and specialized for aerospace systems, limiting accessibility. We present a compact, low-cost wind/dust tunnel (total parts cost < $5k) that replicates desert-like environmental stressors with controlled particle sizes, airflow velocities up to 60 mph, liquid spray, and temperature cycling. The tunnel features a ≥5:1 contraction ratio and holds 2-inch samples behind a transparent window for in-situ optical monitoring. Built from off-the-shelf HVAC parts and standard machine-shop components, the system enables repeatable, systematic evaluation of optical durability. Its modular, easy-to-assemble design allows straightforward customization and transport, making it an accessible platform for optical materials testing, coating development, and device ruggedization studies.