Ventilation

Ventilating is the process of changing or replacing air in any space to provide high indoor air quality, for example to control temperature, carbon dioxide, odors, heat, remove moisture, dust airborne bacteria, smoke, replenish oxygen… So, the purpose of ventilation is to provide fresh (or at least outdoor) air for comfort and to ensure healthy indoor air quality by diluting contaminants.

Ventilation includes both the exchange of air to the outside as well as circulation of air within the building. It is one of the most important factors for maintaining acceptable indoor air quality in buildings. So, methods for ventilating a building may be divided into natural and mechanical.

Natural ventilation

Is ventilation provided by thermal, wind of diffusion effects through doors, windows or other intentional openings in the building.

Mechanical ventilation

Systems circulate fresh air using ducts and fans, rather than relying on airflow through small holes or cracks in a home’s walls, roof, or windows.

This kind of ventilation can be classified in main three groups:

• Supply ventilation systems, where the fresh air is drawn in through an air “intake” vent and distributed to many rooms by a fan and duct system
• Exhaust ventilation systems, where air is continuously exhausted to the outdoors with fans
• Balanced ventilation systems, where equal quantities of air are brought into and sent out of the home and the two most common systems are “heat recovery” ventilation (HRV) and “energy recovery” ventilation (ERV).

Mechanical ventilation may be divided according the place where it is used. In this way, it is divided into home ventilation systems and industrial ventilation systems:

Industrial ventilation

It is a method of controlling worker exposure to airborne toxic chemicals of flammable vapors by exhausting contaminated air away from the work area and replacing it with clean air. Generally, it involves the use of supply and exhaust ventilation to control emissions, exposures and chemical hazards and there are five basic types of ventilation systems: dilution and removal by general exhaust, local exhaust, replacement systems (makeup air), HVAC and recirculation systems. Generally, industrial ventilation involves a combination of these types of systems.

Home ventilation

Home systems use fans to move air into the house and can provide continuous ventilation regardless of the weather and without the need to open doors and windows.