PR2019

Gas-phase air cleaning methodologies have been considered as an attractive and cost-benefit alternative, and supplement to the traditional ventilation systems securing that air quality in buildings is meeting the prescribed standards. The systems can use the air that has been already conditioned to the required temperature and relative humidity, and by removing airborne gaseous pollutants, this air can be supplied indoors again.

In recent years, not only the residence but also the effort of health promotion by improving the social environment including the working and the regional environment has attracted attention. Because of the significant amount of time that office workers spend in the workplace, ideal modification of their working environment and work habits could potentially improve both their intellectual productivity and their physical health. However, optimal environmental improvements have not yet been identified. Therefore, in the present study, we developed a revised version of CASBEE-OHC.

Buildings typically are expected to provide their inhabitants with the opportunity to influence the indoor environment using various control devices. These include, for example, windows, luminaires, radiators, and shading elements. The quality and adequacy of the indoor environment is thus dependent on the availability and effectiveness of such devices. There is arguably a lack of generally agreed-upon evaluation procedures for this aspect of buildings' indoor environment, namely its controllability by building users, or – in the terminology of Human Ecology – its "ecological valency".

Indoor carbon dioxide (CO2) concentrations have been used for decades to evaluate indoor air quality (IAQ) and ventilation. However, many of these applications reflect a lack of understanding of the connection between indoor CO2, ventilation rates and IAQ. In particular, a concentration of 1800 mg/m3 (1000 ppmv) has been used as a metric of IAQ and ventilation without an appreciation of its basis or application.

The current policies and regulatory frameworks in the construction sector aim to improve energy efficiency of new buildings whilst maintaining acceptable level of indoor environmental quality (IEQ) including indoor air quality (IAQ). In practice, however, there are often important trade-offs between these objectives. The aim of this paper is to investigate the concentrations of volatile organic compounds (VOCs) in a recently built residential block in the UK and the potential trade-offs between ventilation rates and VOCs.

With increasing building airtightness, the design of an adequate ventilation system gains importance. The first generation of ventilation systems, based on continuous supply of the nominal airflow rate, are now being replaced by Demand Controlled Ventilation (DCV). These systems, often H2O and/or CO2 controlled, do not take into account the emissions of Volatile Organic Compounds (VOCs) to the indoor environment.

Various studies show a deterioration in indoor air quality after renovation and energy saving measures. NZEB dwellings are at the moment at an airtightness level, that the old slogan make buildings airtight and ventilate right is an very import solution for a good IAQ, but not without source control. 

Low energy buildings are highly insulated and airtight and therefore subject to overheating risks, where Ventilative cooling (VC) might be a relevant solution. VC is an application (distribution in time and space) of air flow rates to reduce cooling loads in spaces using outside air driven by natural, mechanical or hybrid ventilation strategies. Ventilative cooling reduces overheating in both existing and new buildings - being both a sustainable and energy efficient solution to improve indoor thermal comfort (State-of-the-art-review, Kolokotroni et al., 2015).

The current development in building energy efficiency towards nearly-zero energy buildings (nZEB) represents a number of new challenges to design and construction. One of the major new challenges is the increased need for cooling arising in these highly insulated and airtight buildings. The cooling demand depends less on the outdoor temperature, and more on solar radiation and internal heat gains. This naturally gives better potential for the use of ventilative cooling technologies, because the cooling need is not only in summer, but actually all year round.