IAQ

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. 

As an alternative to adopting active architectural systems (mechanical systems) and taking advantage of the resources provided by nature, natural ventilation contributes interesting solutions to control the thermal balance and the air quality, and it is applicable in a variety of climate zones. Natural ventilation also solves some of the more common problems of mechanical systems, such as the noise factor and installation and maintenance costs.

This paper reports on research to analyze the indoor air quality (IAQ) and the concentration and varying patterns of CO2, formaldehyde and TVOC in commercial buildings located in Chongqing, South-West China. Two buildings were monitored during the day over two weeks in the summer period. One was a completed building that had been fully operational for several years. This building is termed the ‘non-renovated’ building. The other was a commercial building of similar age that was currently undergoing renovation on one of the main retail floors.

The ventilation required in order to maintain acceptable indoor hygiene standards results in a significant consumption of energy. Currently the Spanish regulations on indoor air quality (IAQ) require minimum rates for delivery-to and extraction-from the habitable rooms of residential buildings. These rates are not adjustable, so ventilation systems based on variable ventilation rates, are not normally deemed acceptable unless a comprehensive statement of compliance is provided, justifying the proposed ventilation solution.

French authorities have launched an extensive thermal renovation program aiming at retrofitting 4M dwellings over 10 years, with priority given to the most energy consuming ones. Without specific focus on airtightness, retrofitting does not achieve very low airtightness levels, which means numerous leaks in the envelope. Added to the possibility of fungus development at the junction between ancient and new wall, the possibility of airflow conveying pollutants emitted in walls into indoor air is a major concern for public health.

The present article deals with the energy classification and the environmental evaluation of the school buildings in Greece. The energy performance of the school buildings, in relation to the normalized annual consumption for heating regarding floor area and climatic conditions, was rated using clustering technique (K-means algorithm) and an energy classification tool developed. The audited school buildings were classified into five energy categories.

Hybrid ventilation (HV), as a combination of automated natural ventilation (NV) and balanced mechanical ventilation (MV), provides opportunities to use the advantages of both ventilation systems during the seasons in order to reduce energy demand and at the same time obtain comfortable indoor climate.

Sizing rules in residential ventilation standards lack uniformity in both methodology and resulting design flow rates. Additionally, mere comparison of design flow rates is case sensitive and, due to effects of infiltration, adventitious ventilation and occupancy, ill-suited to assess performance of an exhaust ventilation system with regard to the achieved indoor air quality and energy cost in terms of heat loss.

Sizing rules in residential ventilation standards lack uniformity in both methodology and resulting design flow rates. In order to investigate the best achievable performance of natural ventilation, exhaust and fully mechanical ventilation systems, this paper presents a multi-zone simulation based optimization study for both a detached dwelling.