CTE DB HE. Distribution conditions of a ventilation system in a home

As construction systems have evolved, so too have the insulations and the exterior envelopes of buildings, leading to the emergence of new ventilation systems to efficiently supply clean air indoors and meet the requirements of the C.T.E. in its Basic Document HE. (CTE DB HE): "Energy Saving". These construction advances allow for a very high level of airtightness, requiring the introduction of outside air to achieve acceptable ventilation levels.

On the other hand, the requirement to comply with national regulations (C.T.E. HE-HS, RITE) and European regulations advises the classification of ventilation systems as follows:

Ventilation systems according to the requirements of CTE DB HE

• System A: Natural supply and natural extraction.
• System B: Mechanical supply and natural extraction.
• System C: Natural supply and mechanical extraction.
• System D: Mechanical supply and mechanical extraction.
• Combined systems

System A

In natural ventilation systems without fans, the wind pressure on the facades and the movement of air due to temperature differences are utilized. This system was already used in many old homes, where the supply of outside air was through defective sealing of doors and windows. In modern homes, this option is discarded due to its inconvenience and high energy consumption. In this ventilation system, outside air is taken through adjustable openings on the facade and extracted from the interior through vertical ducts that serve all floors of the home and exhaust the air through the roof. Its advantages include its silent operation and that it does not consume electricity. However, the airflows are not guaranteed but depend on thermal conditions and wind pressure outside.

System B

In mechanical ventilation systems, one or more fans are used to perform the admission of air. For this purpose, a fan is connected to vertical ducts that serve all floors where air is admitted. Extraction is performed in a separate system that works naturally through grills in the humid areas that connect with a vertical duct leading to the roof. This way, the specifications of CTE DB HE. "Energy Saving" and HS. "Health" are met.

System C

In this system, the admission of clean air is done through adjustable grills by natural or mechanical means located on the facade. Extraction of contaminated air is done through an extractor connected with vertical ducts to the humid areas (bathrooms, toilets, and kitchen) where the stale air is expelled outside. Its advantages include that the airflow is guaranteed and that it requires minimal maintenance.

System D

This system has both mechanical admission and extraction, ensuring guaranteed airflows. It is a relatively new system introduced about a decade ago. Before installation, it is essential to consider the noise level of the entire system, which can be negatively affected by low-quality motors or poor duct installation. The most common is the centralized admission and extraction system via mechanical means, using a network of ducts for the entire home. This installation can be unified in a heat recovery unit composed of a heat exchanger, air filters, one fan for supply, and another for extraction.

Combined systems

The most common combination is between System C and System D, providing more comfort in common areas such as the living room or dining room in the home.