English

The differences between extract ventilation and balanced ventilation are subject of many discussions in sales markets where both solutions have their share. Often, the differences are marked in terms of energy, because balanced ventilation is normally accompanied by heat recovery. But there is another difference in terms of the ventilation effectiveness of the system.This document reports experiments in a scale model of a house showing the difference between extract ventilation and balanced ventilation in ventilation effectiveness, and therefore in achievable indoor air quality.

The long term exposure to fine particulate matter with a diameter of ≤2.5 μm (PM2.5) is linked to numerous health problems, including chronic respiratory and cardiovascular diseases, and cancer. In dwellings, a primary emission source of PM2.5 is cooking, an activity conducted several times per day in most households. People spend over 90% of their time indoors and more time in their homes than any other type of building. Therefore, they are at risk of exposure to elevated levels of PM2.5 emitted by cooking if these particles are not removed at source.

At typical indoor CO2 levels there is no scientific evidence that CO2 is harmful to comfort and health of healthy persons, though there is a potential for negative effects on some aspects of performance. Research also indicates that insufficient bedroom ventilation may negatively affect the quality of sleep.

Pressure drop due to filters embedded in HVAC systems is one of the energy loss causes in building air conditioning systems, which can become important in large all-air systems with highly demanding filtering needs, such as hospitals, clean rooms, laboratories or pharmaceutical environments.

To study the impact of the filtration efficiency level on the particle concentration in a rural school equipped with a balanced ventilation system with heat recovery, measurements of indoor and outdoor particle concentrations have been carried out by using three different efficiency filters. The tested filters are respectively classed G4, F7 and F9 according to NF EN 779 (2012).

Radon gas is a pathological agent confirmed by World Health Organization in terms of increasing the risk of lung cancer generation when it is inhaled by human in high concentration. This gas comes from soils with uranium content (i.e. granite terrain) and penetrates through the building envelope, such, as floors or basement walls. Its accumulation in indoor spaces increases the radon concentration level, constituting a health problem for occupants. This can be handled by rehabilitation actions in buildings that reduce indoor concentration to acceptable levels.

The aim of this paper is to show the effects of variable ventilation rates on the demand of energy and air quality in dwellings, and how airtightness and wind affect this relation. It is interesting to estimate the relation between the air ventilation rate and airtightness of dwellings which makes the dwelling to be under-pressure in order to avoid infiltrations.

Within this paper, an evaluation of Indoor Air Quality in residential buildings, and the experience after a building retrofit is shown. One residential building in a Madrid social housing neighbourhood serves as case study and base for the monitoring. 

People in industrialised countries spend about 90% of their time indoors. Hence, a good indoor climate is essential for health and well-being. Ventilation of buildings plays an important role concerning health aspects of the occupants and inadequate ventilation may cause health costs that may have been avoidable if ventilation would have been adequate. Additionally, good or bad ventilation has impacts on the quality of the building, e.g. in very tight buildings, the risk of mould and dampness is higher if air change is insufficient.

The purpose of this paper is to enhance the importance of ventilation regarding energy use and stablishing methods in order to obtain as much data as possible about the behavior patterns of ventilation and infiltration in buildings.