A good idea that does not work.

The fan does not blow enough air into the helmet. If you wear the unit while actively working, your heavy breath will overwhelm the weak air flow.Other reviewers have pointed out the great combination of helmet, hearing protection, face shield and air cleaning. There just is not enough airflow to keep the face shield from fogging up. The helmet gets so hot it is intolerable. Many reviewers mention the problem in passing. I should have paid more attention. Professional units like the one made by 3M cost a lot more but they work.