Exhalation of buildings

Residential buildings can act as sources of pollutant emissions, contributing up to 50% of the pollution generated in cities.

The main goal of this research project (https://ambiun.com/exhal/) is to analyze, quantify and reduce the transfer of air pollutants from residential building ventilation systems to urban environments.

Ventilation systems refer to the set of ducts, sensors and machines responsible for extracting contaminated air from wet rooms, kitchen exhaust hoods, sanitation networks and garages and taking it to the outside. A set of systems that respond to the concept of building exhalation that will be developed in the project.

Firstly, with respect to wet rooms and their implications for ventilation in dwellings, there is an extensive scientific literature that analyzes the quality of outdoor air in buildings, indoor air quality requirements, or that quantifies quality parameters in existing buildings. As an overview, it can be said that ventilation systems are responsible for introducing outdoor air into buildings, modifying the indoor air quality characteristics to achieve the objectives required by rules and regulations.

On the other hand, through kitchen extractions, pollutants that the scientific literature has associated with a significant production of pollutants, such as particulate matter (PM), are evacuated. In addition, the ventilation pipes of the sewage networks represent a methane source that has hardly been studied in high-rise residential buildings. It should be remembered that methane (CH4) is one of the most important greenhouse gases after CO2.

subject Finally, garages are facilities that generate a varied amount of atmospheric pollutants whose composition varies depending on the engine and fuel used by the vehicles they house, and in all cases they are particularly dangerous for people.

This combination of polluted air is expelled in a generic way through the roofs of the buildings, without at this time a precise quantification of pollutants such as CO, CO2, CH4, PM and volatile organic compounds (VOC), which are emitted into the atmosphere by the residential housing stock as a whole and which, sooner or later, return to the interior of the buildings. The correlation between the different ventilation systems and the discharges produced is also unknown. That is, the existing programs of study allows us to know the indoor pollution in different scenarios, but we do not know if it is the same pollution that is discharged into the atmosphere or if it is altered in some way.

Therefore, the research of this project aims to systematize the concept of exhalation in residential buildings, to quantify the pollutants released into the atmosphere in several residential buildings with different ventilation systems, and to adopt measures to reduce or eliminate these pollutants, as well as to consider their energetic or material valorization when possible.

This project (PID2019-104083RB-I00) has a duration of 4 years (2020-2024) and has been funded by the Ministry of Science, Innovation and Universities, within the call for Projects of research and development+i Challenges research: challenge main - 5 Climate change and use of natural resources and raw materials.

Participating entities:

• department Construction, Facilities and Structures.

• department from Environmental Biology.

• department of Mechanical Engineering and Materials of the University of Navarra.