Cleanroom performance optimization is paramount to providing consistent manufacturing yield goals. Cleanrooms and Critical Enclosures are typically designed for a particular purpose or process. Over time these environments can morph to include parameters and processes not originally contemplated, oftentimes creating unexpected environmental issues. Sometimes age and lack of maintenance cause environmental performance degradation that can transfer to product quality issues. We routinely provide our expertise through facility characterizations and studies that can allow users to get back on track and derive the most from their Cleanroom investments.