Cleanroom classification
ISO 14644-1 defines cleanroom classifications based on the concentration of airborne particles ≥0.1 µm. Classes range from ISO 1 (cleanest) to ISO 9 (least clean). ISO 5 to ISO 8 are the most common in manufacturing.
Cleanliness is controlled by airflow and filtration, measured in air changes per hour (ACH). ISO 5 environments often require over 240 ACH, while ISO 8 may need as few as 10.
Note: Values shown are estimates. Actual ACH can vary with room size, layout, airflow type, and process intensity.
What is a minienvironment?
A minienvironment is a sealed enclosure built around a specific machine or workstation. It creates a localized clean area without requiring full-room control. These enclosures include HEPA or ULPA filters, pressure control, and optional temperature or humidity regulation.
Because they treat a small air volume, they significantly reduce HVAC load and facility footprint.
Why use a minienvironment instead of a full cleanroom?
Traditional cleanrooms require extensive construction, HVAC upgrades, and strict gowning protocols. But when only one step in production needs clean air, this approach is excessive. Minienvironments eliminate the need for dedicated cleanroom space, install in weeks rather than months, consume less energy and filtration, and minimize operator gowning and workflow disruption.
Minienvironments are ideal for:
- retrofitting existing areas to achieve stricter ISO levels
- adapting to product or customer specification changes
- modular lines combining clean and non-clean processes
These types of cleanrooms are widely used in electronics (MEMS, camera modules, PCB assembly), automotive (optical sensors, HUDs, lighting), pharma/biotech (filling, inspection stations), semiconductors (tool enclosures, front-end process zones), and battery production (dry room zoning, module assembly. Their modularity makes them ideal for clean process islands in mixed environments.
Engineering principles of minienvironments
Core design elements include:
• Sealed enclosure: Uses aluminum, stainless steel, or polycarbonate panels
• Airflow: Unidirectional (0.3–0.5 m/s) for ISO 5–6; turbulent for ISO 7–8
• Filtration: HEPA (≥99.97% @ 0.3 µm) or ULPA (≥99.9995% @ 0.12 µm)
• Pressure differential: Maintains 0.2–5 Pa to prevent particle entry
Air is supplied via fan-filter units (FFUs), and zones can be classified independently. Systems operate on demand.
Real-time monitoring ensures optimal conditions are maintained. Minienvironments are equipped with particle counters to detect airborne contamination, pressure sensors to verify positive pressure relative to ambient conditions, and optional temperature and humidity sensors for sensitive processes.
Data integrates with MES or SCADA platforms for traceability, alerts, and compliance. Systems align with ISO 14644-2 and 21 CFR Part 11 standards.
Traditional cleanroom vs. minienvironment infrastructure comparison
Minienvironments reduce the need for full-scale cleanroom infrastructure, especially in buildings not originally designed for controlled environments.
| Requirements | Traditional cleanroom | Minienvironment |
|---|---|---|
| Structural modifications | Ceiling/grids needed | None (self-supporting) |
| HVAC load | High (room-scale) | Low (localized) |
| Footprint | Dedicated clean zone | Built around machine |
| Gowning requirements | Full-body protocol | Minimal gowning required; |
| Deployment time | Months | Days to weeks |
Energy and cost efficiency
Minienvironments reduce air volume, ACH, and runtime. Where traditional cleanrooms run 24/7 with centralized HVAC, minienvironments use local FFUs with EC motors and on-demand control.
Minienvironment conditions deliver significant savings—cutting energy use by 60–86%, reducing filter replacements by around 50%, and lowering operating costs by 30–40% over a 3–5 year period.
| Cleanroom type | Traditional cleanroom | Minienvironment |
|---|---|---|
| ISO 5 power density | 500–1000 W/m² | ~200–300 W/m² |
Case study: automated backlight assembly
In an automotive display assembly line, 26 components are assembled into a backlight unit. ISO 7 was required, but the hall only met ISO 8. Instead of retrofitting the room, minienvironments were placed over each workstation.
Result was a fully ISO 7-compliant assembly line in an ISO 8 space with no facility disruption.
Read the full case study here.
Minienvironments: scalable, efficient, and built for precision manufacturing
Minienvironments provide a proven, technically robust alternative to full-scale cleanrooms in contamination-sensitive manufacturing. By isolating clean conditions at the point of use, they reduce capital costs, save energy, shorten deployment timelines, and improve workflow flexibility—all without compromising ISO-class performance.
For manufacturers facing quality, regulatory, or customer-driven cleanroom demands, minienvironments deliver the required control with unmatched efficiency and scalability.