Houses

People spend the majority of their time in their own homes and so the indoor environmental conditions are an important determinant of population health and wellbeing and have economic consequences. Chile is undergoing rapid economic growth and is managing its national energy demand to minimize its greenhouse gas emissions. Its housing stock is growing rapidly, and is responsible for 15% of national energy demand. Accordingly, there is a need to understand the performance of the stock by measuring parameters that indicate air quality, thermal comfort, and energy demand.

As UK homes are insulated and draught proofed in an attempt to reduce wintertime heating demand they become more airtight. Any reduction in infiltration could have a detrimental effect on indoor air quality. Controllable background ventilation provided by trickle vents is one method of maintaining indoor air quality.

Traditionally, houses in the U.S. have been ventilated by passive infiltration in combination with active window opening. However in recent years, the construction quality of residential building envelopes has been improved to reduce infiltration, and the use of windows for ventilation also may have decreased due to a number of factors. Thus, there has been increased interest in engineered ventilation systems for residences.

Formaldehyde, less-volatile aldehydes, and terpene hydrocarbons are generally the predominant air contaminants in new manufactured and site-built houses. This study was conducted to identify the major sources of these compounds in a typically constructed, new manufactured house. Specimens of materials used within the house envelope were collected from the production facility. These were individually preconditioned for 19 4 days and tested for emissions of formaldehyde and the other target compounds using small-scale chambers.

Tracer gas techniques have been the most appropriate experimental method of determining airflows and ventilation rates in houses. However, current trends to reduce greenhouse gas effects have prompted the need for alternative techniques, such as passive sampling. In this research passive sampling techniques have been used to demonstrate the potential to fulfil these requirements by using solutions of volatile organic compounds (VOCs) and solid phase microextraction (SPME) fibres.

In Denmark, a new survey of indoor radon-222 has been carried out. One-year alpha trackmeasurements (CR-39) have been done in 3019 single-family houses. There is from 3 to 23 housemeasurements in each of the 275 municipalities. Within each municipality, houses have been selectedrandomly. One important outcome of the survey is the prediction of the fraction of houses in eachmunicipality with an annual average radon concentration above 200 Bqm-3.

Numerical modelling is a powerful tool for studies of soil gas and radon-222 entry into houses. It isthe purpose of this paper to review some main techniques and results. In the past, modelling hasfocused on Darcy flow of soil gas (driven by indoor-outdoor pressure differences) and combineddiffusive and advective transport of radon. Models of different complexity have been used. Thesimpler ones are finite-difference models with one or two spatial dimensions. The more complexmodels allow for full 3D and time dependency.