The grille inside your home's ventilation system

The main function of the grille within ventilation systems is to allow air to pass through. This air passage may serve to supply air to the rooms of the home (inlet openings) or to extract the stale and contaminated air that the usual use of the rooms produces (extraction openings). To capture, distribute, or extract air, they can be installed directly on the building's envelope or connected to the ductwork of the ventilation system. In any case, it is an element with an aesthetic and design component that must be considered when designing the spaces in our homes.

Types of grilles

There are various types of grilles available on the market made from different materials (plastic, aluminum, stainless steel, mixed); finishes (matte, glossy, polished); geometries (circular, rectangular, square, linear). Their arrangement in the premises can also vary (ceiling or wall). Depending on their control over the passage of air, they can be classified as fixed, adjustable, self-adjusting, or humidity-regulated. We must consider that the renewal of the indoor air in our homes should occur with the minimum possible energy consumption. Therefore, it is important to have autonomous systems that ensure an optimal balance and interior air quality according to occupancy and use.

Taking the above into account, from the perspective of energy efficiency, it is highly recommended to install self-regulating and humidity-regulating grilles. A self-regulating grille will allow the system group to supply and extract a constant airflow, preceded by monitoring by the user. This is a very interesting aspect from the standpoint of health and well-being, as a pressure difference (due to a difference in flow rates) negatively affects the occupants. On the other hand, a humidity-regulating grille will allow the ventilation group to establish the airflow within healthy relative humidity parameters.

Design of the ventilation system

Both the sizing and the location of the grilles (for both extraction and supply) must be taken into consideration from the design phase of the project. An insufficient airflow will not guarantee proper air renewal in the rooms. On the other hand, an excessive airflow in a direction that directly impacts the occupants will hinder comfort and well-being. We must ensure that between the supply and extraction grilles there is a sweeping effect capable of renewing the air and extracting the contaminated air. For this, it is crucial to properly size the ducts and grilles, and to adequately distribute the latter.

What does the regulation say?

According to the CTE, supply openings, if located directly on the building's envelope, must incorporate a through wall, sealed at its ends with the wall. Additionally, it must include the necessary protection devices to prevent water from entering inside. In the case that these protective elements are made of slats, they should be arranged in the same direction as the flow of air.

As for extraction openings, the Technical Code of Building establishes that if they are coupled to a duct network, they must be equipped with protective elements that prevent the entry of unwanted objects. The extraction grille will be located, on one hand, at a distance from the ceiling not exceeding 20 cm and, on the other hand, at a distance from any corner of at least 10 cm.