Abstract: An exhaust unit includes a dirty air intake opening, a clean air output opening and an airflow path defined between the dirty air intake opening and the clean air output opening. The exhaust unit further includes an upstream quenching section and a downstream filtering section along the airflow path. The quenching section has a wetting chamber that includes a reservoir having a fill level for a quenching liquid, and a downtube connected over the dirty air intake opening and opening at its end above, and in opposition to, the plane of the fill level.