How the Technical Code Influences the Ventilation System

The entry into force in 2006 of the Technical Code of Construction highlighted a series of demands regarding air quality that changed the way homes must be ventilated. As the Technical Code states: “Buildings shall have means for their spaces to be adequately ventilated, eliminating the pollutants produced habitually during the normal use of buildings, so that a sufficient flow of outdoor air is provided and the extraction and expulsion of air contaminated by pollutants is guaranteed.”

Technical Code of Construction and Ventilation

Thus, the Technical Code establishes the obligation for homes to incorporate a general ventilation system, which can be hybrid or mechanical, so that air circulates from dry areas (bedrooms, living rooms, and dining rooms) to humid areas (kitchens, bathrooms, and laundry rooms).

How does this influence the design of our home?

Since a minimum ventilation flow must be supplied to the spaces (inflow in dry areas and extraction in humid areas), it will be necessary to have intake openings in the former and extraction openings (connected to extraction ducts) in the latter. In addition, the vertical surfaces acting as separation between these will need to provide pass openings to facilitate air sweeping.

In the case of kitchens, the regulations set forth a specific mechanical ventilation system (extractor hood) independent of the general ventilation of the home.

Technical Specifications

Extraction

Extraction Openings

• The extraction openings will be connected to extraction ducts. The distance to the ceiling shall not exceed 20 cm and the distance to any corner of the premises shall not be less than 10 cm.

Extraction Vents

• The extraction vents shall be placed on the roof of the building at a distance no less than 300 cm from any air intake, whether it is an inflow vent or a window. This same distance must be maintained regarding areas where people usually gather (terraces, balconies, etc.).

• If the ventilation system is hybrid (only the extraction occurs by mechanical means), the external end of the extraction duct must be located on the roof, maintaining a minimum height above its surface. In the case of non-walkable roofs, the height will be one meter from the last finishing layer of the roof. In the case of walkable roofs, the expulsion vent must be at least 2 meters away from the walkable surface. If there are obstacles, the vent must exceed the height of any element that is more than 2 meters and less than 10. It must have a height 1.3 times the height of any obstacle that is 2 meters or less from 2 meters.

Extraction Ducts

• The extraction ducts can serve multiple bathrooms, kitchens, and storage rooms simultaneously. They can never be shared with the specific ventilation of the kitchens.

• If the extraction ducts are collective (serving more than one dwelling in a multi-family building), they cannot serve more than 6 floors.

• The ducts must be vertical and their interior finish must be smooth to avoid dirt accumulation.

If they are in contact with the outside, both the opening and the extraction vent (the external end of the duct) must be protected to prevent rainwater entry.

Admission

• If the admission opening is in contact with the outside, it must be protected to prevent rainwater from entering from the outside.

• The cross-section of the admission ducts must be homogeneous and have an interior finish that prevents dust and dirt accumulation. They must be inspectable every 10 meters at minimum and cannot have elements that obstruct airflow throughout their length.