Mechanical ventilation

Mechanical ventilation is the intentional fan driven flow of outdoor air into a building. Mechanical ventilation is often provided by equipment that is also used to heat and cool a space.

Fundamentals of mechanical ventilation

Mechanical ventilation is one of the systems that keeps a habitable environment.

Purpose of mechanical ventilation:

  • To heat or cool the incoming air
  • To circulate/move the air in a room
  • To supply/exhaust the required air amount in the room

Basic information about mechanical ventilation:

  • Ventilation is operable independent on exterior conditions
  • Requires precise operation control
  • Provides temperature and humidity (and other sources) control

Mechanical ventilation is based on pressure difference and caused by dynamic pressure of a mechanical device - fan/blower.

Ventilation consists of 3 main parts:

  • Ventilation rate – the amount and quality of the outdoor air
  • Airflow direction – the flow of air within a building, from “clean” to “dirty” areas
  • Air distribution – the delivery of outside air and removal of pollutants

Basic principles of mechanical ventilation:

  • Overpressure ventilation
  • Balanced ventilation
  • Underpressure ventilation

Mechanical ventilation consists of several parts, i.e. air handling unit (AHU), ducts, air supply/exhaust devices, dampers, fan coils, heating/cooling unit,  etc.

Important terminology used in mechanical ventilation