Ventilation systems for efficient and sustainable housing

Currently, we have multiple efficient ventilation solutions capable of providing our interiors with healthy and quality air. Do you know the different ventilation systems for homes that exist in the market? In this article, we present them to you.

Ventilation and current regulations

According to the CTE DB HS 3 Air quality, homes must have a hybrid or mechanical ventilation system that guarantees the expulsion of contaminated indoor air and the inflow of clean outdoor air. Considering the increasing airtightness of new buildings (to comply with sustainability and environmental requirements), equipping our homes with an efficient ventilation system is a primary concern.

Quality indoor air will be free of contaminating particles and with an appropriate humidity level that does not jeopardize people's health. How to achieve efficient ventilation? There are different strategies: variable flow ventilation systems, hygrosensitive systems (depending on occupancy), systems that incorporate energy recovery devices, devices that use passive strategies (bypass or night cooling systems, so overheating is not penalized), Canadian well (or Provencal)...

Hybrid ventilation (natural + mechanical)

Also called stratomechanical ventilation, it consists of taking advantage of the conditions of the Venturi Effect. When environmental pressure and temperature conditions are favorable, air renewal occurs as in natural ventilation; when they are unfavorable, as in mechanical extraction ventilation.

It is a system widely used in rehabilitation works (where the seal and airtightness of the envelope is improved), as it enhances ventilation without the need for extensive work. Rehabilitation works aimed at improving energy efficiency in buildings must consider modifications to their ventilation systems, as energy improvements cannot compromise indoor air quality of the premises.

Mechanical ventilation

It can be single flow or double flow. In the former, extraction occurs only through mechanical means (injection occurs through grilles located at the top of the exterior joinery). In the latter, both injection and extraction occur through mechanical means. They can be of constant flow or variable flow, depending on the use of the premises, their occupancy, and the climatic zone where the building is located.

Both the single flow and double flow systems can be individualized or centralized. We talk about individualized systems when each of the homes in a multifamily building has its own extraction point. We talk about centralized systems when there is one extraction point for all homes.

Advantages of double flow mechanical ventilation

Double flow mechanical ventilation systems offer multiple advantages. Being fully controlled, airtight, and sealed systems, they ensure that the injected air is healthy, free of contaminating particles. If, in addition, it incorporates sensors that adjust the humidity of the injected air to the indoor humidity, a quality indoor air is achieved with ideal hygrometric characteristics that avoids the discomfort that a very high or very low humidity rate can cause for occupants.

According to European regulations, systems must be energy-efficient and energy losses must be minimal. Double flow mechanical ventilation systems can incorporate energy exchangers capable of recovering up to 90% of the heat energy from the ventilation process itself, thus reducing the energy bill. In winter, continuous air renewal is achieved by using the internal energy to temper the air coming from the outside. In summer, the programming of free cooling with a bypass valve can be used at night. This way, instead of bringing in air and crossing it with the extraction, the low night temperatures are utilized to inject fresh and clean air indoors, simultaneously expelling the hot and contaminated air inside.

In the case of limited space or rehabilitation works, there are compact ventilation units that do not require much space. For specific cases, there is also the possibility of installing decentralized systems by room, rather than by housing.