Technical Building Code, how does it influence the ventilation system?

In this article, we will highlight the main requirements of the Technical Building Code specified in the CTE DB HE, Energy efficiency. These requirements, addressing the demand parameters and the need to meet energy savings objectives, affect both the design of ventilation systems and those of air conditioning.

The Technical Building Code on energy savings

The CTE DB HE establishes a series of regulations to ensure a rational use of energy, so that only the energy that is truly necessary is consumed. To fulfill this purpose, buildings must be designed, constructed, used, and maintained efficiently.

In its first chapter, CTE DB HE 1, Limitation of energy demand, the document determines that buildings must have an envelope, in accordance with the climate in which they are located, that minimizes energy losses. To this end, it emphasizes the importance of increasing thermal insulation and inertia of the exterior walls, controlling thermal bridges, and preventing condensation-related moisture from appearing.

It is about limiting energy demand, that is, “the useful amount of energy necessary that technical systems would have to provide to maintain defined regulatory conditions inside the building based on the building's use (use profiles) and the climatic zone in which it is located (reference climate). It can be divided into energy demand for heating, cooling, domestic hot water (DHW), and lighting, and is expressed in kW•h/m2.year, considering the usable area of the building's habitable spaces.”

Regulations and ventilation

An inadequate envelope, the need to constantly ventilate spaces, and unwanted air inflows can lead to significant losses of heat energy. A good controlled mechanical ventilation system, in which both the supply and extraction are produced by mechanical means, will ensure the proper renewal of air inside all rooms.

Compared to hybrid or natural ventilation, it is the most efficient ventilation system from an energy savings standpoint. Being a completely airtight and controlled system, it prevents unwanted air inflows. Additionally, thanks to the heat recoverers it incorporates, it is possible to recover up to 90% of the energy from the very ventilation process.

The Technical Building Code places special emphasis on the need to incorporate adequate thermal installations that ensure the thermal comfort of its occupants. With a good thermal envelope, thorough control of thermal bridges and uncontrolled air inflows, and an efficient ventilation system that ensures quality indoor air, it is possible to reduce the energy demand of these thermal installations (and even eliminate them).

The continuous rise in energy prices and increasingly stringent regulations on sustainability and environmental protection force a paradigm shift. It is time to question conventional heating and cooling systems and transition to passive systems that maximize both solar energy and the energy generated inside the building.