Dynamic ventilation, adopted in the most sensitive departments (farrowing, weaning, insemination, boars and gestation in warm climates), is an active negative-pressure system based on extractors (wall-mounted or chimney) managed by electronic control, which modulates the airflow rate according to the difference between set and actual temperature. Fresh air enters through aerodynamic inlets self-regulated by the negative pressure (≈3–5 Pa), ensuring correct air throw. When air exchange alone is not sufficient, auxiliary systems intervene: adiabatic cooling or heating. In winter, minimum ventilation controls humidity and gases (CO₂, NH₃), preventing condensation; in summer, it keeps the internal temperature close to the external one.

The design of the building envelope is crucial: structures sized with calculation models for ventilation and insulation, free from thermal bridges and with thermally broken walls, to reduce consumption and guarantee drier, more stable bedding.

This is a real system essentially consisting of a wet plenum with the spraying of nebulised and treated water, whose function is to wash the air which, pushed by the extractors forming the normal air exchange system installed in the farm, passes through the plenum transversely to the sprayed flow. In this volume, the dust is wetted by the water and is thus captured by the outlet filter barrier. As regards ammonia abatement, there are two levels of action: with or without additives. Without additives, ammonia abatement efficiency is around 20–25%, while by adding an acid solution (e.g. sulphuric acid) to the nebulised water, a reduction efficiency ranging from 50 to 80% can be achieved.