Module Assembly Hard Wall Clean Room has been demonstrated through scientific testing that using filters would keep particular quantities and sizes of air particles out of a cleanroom. This positive pressure prevents contaminated air from entering the cleanroom through perforated apertures, assisting in maintaining the regulated amount of clean air. Module Assembly Hard Wall Clean Room uses HEPA/ULPA filtering technology to create a degree of clean air quality. Filter fan circulate non-filtered air, generating a positive pressure environment inside the cleanroom.