Do you know what substances cause environmental pollution?

Environmental pollution

Environmental pollution or external contamination began slowly and progressively with the industrial revolution, and today it represents a serious problem in many urban areas of the planet. Its existence is mainly due to combustion processes, which involve the emission of carbon monoxide, nitrogen oxides, ashes, and unburned hydrocarbons. When these chemical components reach high concentration levels, they can cause health problems and very harmful effects on the environment, such as global warming and the presence of greenhouse gases.

At the same time that efforts are made to reduce these emissions, it is necessary for buildings to meet their thermal needs with low energy demand. For this, it is essential that buildings are very airtight to avoid thermal losses due to infiltration in the facade enclosures, as well as to promote a very efficient use of the energy used for climate control. All these energy, environmental, and health aspects, along with the need to have good indoor comfort in homes, avoiding the appearance of moisture due to condensation, have resulted in the development of special regulations in each country to ensure good indoor air quality in buildings. In Spain, the current regulatory framework that regulates this is the Technical Building Code, C.T.E. (2006) and the Regulations on Thermal Installations in Buildings, RITE (2007).

Mechanical double flow ventilation and Nearly Zero Energy Buildings

Natural ventilation systems contradict the principles stated earlier, as they expel flows of contaminated air in good thermal conditions and replace them with other new air flows that need to be climatically conditioned. All of this results in a very high energy consumption. For this reason, mechanical double flow ventilation systems have been developed. This type of ventilation incorporates a heat recovery system that makes it a very efficient system as it allows obtaining heat from the extracted interior air and transferring it to the flow of clean air introduced from outside. This process is performed with independent circulation of both air flows, which do not need to mix for thermal energy transfer to take place. The other main components that make up a double flow ventilation system are: the distribution box, supply ducts in dry rooms, and extraction ducts in wet rooms. Proper functioning of the installation also requires that the sizing of the flows allows for an equilibrium between the volume supplied and the volume extracted.

Efficient ventilation systems are employed in an environment where there is an increasing demand for a type of construction with high energy efficiency. In this sense, the 2010/13/EU Directive of the European Union promotes that there be regulatory changes in the different member countries so that from December 31, 2018, all new buildings occupied or owned by public authorities be Nearly Zero Energy Buildings, referred to as nZEB in English (Nearly Zero Energy Building). These types of buildings are characterized by consuming energy derived from the building itself, through renewable energy sources, which must equal the energy demanded by the building.