indoor air quality

This study copes with the problem of ventilation in existing educational environments in terms of indoor air quality (AIQ), comfort and energy consumption. In accordance with international regulations, densely occupied environments such as school classrooms need high air change rates in order to provide sufficient fresh air. Nevertheless, in Italian schools, it is rare to see mechanical ventilation systems or natural systems that are mechanically controlled. This means that it is necessary for the users to control air changes by opening or closing the windows.

The provision of good IAQ in schools is important both for the health of students and in maximising educational achievement. It is, however, common for school classrooms to be significantly under-ventilated and this can lead to high levels of CO2 and other pollutants. Natural ventilation offers the potential to improve IAQ within schools whilst, at the same time reducing running and maintenance costs. Accordingly, this article examines a natural ventilation strategy based on the use of a roof mounted split-duct Windcatcher ventilator. Here, 16 U.K.

Most dwellings in the United States are ventilated primarily through leaks in the building shell (i.e., infiltration) rather than by whole-house mechanical ventilation systems. Consequently, quantification of envelope air-tightness is critical to determining how much energy is being lost through infiltration and how much infiltration is contributing toward ventilation requirements. Envelope air tightness and air leakage can be determined from fan pressurization measurements with a blower door. Tens of thousands of unique fan pressurization measurements have been made of U.S.

We describe a novel modeling technique, based on Duhamel's theorem, to study the effects of time-varying winds on radon transport in soil near buildings. The technique, implemented in the model RapidSTART, reduces computational times for transient, three-dimensional, wind-induced soil-gas and radon transport by three to four orders of magnitude compared with conventional finite-dierence models.

Indoor air quality (IAQ) in new houses, particularly occupant's inhalation exposure to toxic, irritant and odorous chemicals, has received comparatively little attention among house builders and product manufacturers. The volatile organic compounds (VOCs) of potential concern in new houses include formaldehyde, acetaldehyde, acetic acid and naphthalene. These VOCs are emitted by a variety of wood products and other materials used to finish the interiors of most houses.

Age of air is a technique for evaluating ventilation that has been actively used for over 20 years. Age of air quantifies the time it takes for an elemental volume of outdoor air to reach a particular location or zone within the indoor environment. Age of air is often also used to quantify the ventilation effectiveness with respect to indoor air quality. In a purely single zone situation this use of age of air is straightforward, but application of age of air techniques in the general multizone environment has not been fully developed.

The role of ventilation in the housing stock is to provide fresh air and to dilute internally-generated pollutants in order to assure adequate indoor air quality. Blower doors are used to measure the air tightness and air leakage of building envelopes. As existing dwellings in the United States are ventilated primarily through leaks in the building shell (i.e., infiltration) rather than by whole-house mechanical ventilation systems, accurate understanding of the uses of blowerdoor data is critical. Blower doors can be used to answer the following questions:.

A study to measure indoor concentrations and emission rates of volatile organic compounds (VOCs), including formaldehyde, was conducted in a new, unoccupied manufactured house installed at the National Institute of Standards and Technology (NIST) campus. The house was instrumented to continuously monitor indoor temperature and relative humidity, heating and air conditioning system operation, and outdoor weather. It also was equipped with an automated tracer gas injection and detection system to estimate air change rates every 2 h.

The aim of this report is to provide information and advice to policy and decision makers, researchers, architects, designers, and manufacturers on strategies for achieving a good balance between good indoor air quality (IAQ) and the rational use of energy in buildings, available guidelines and assessment techniques on energy and IAQ, significant trends for the future with implications for IAQ and the use of energy in buildings; and an indication of current research issues.

This report provides information and advice to policy and decision makers, researchers, architects, designers, and manufacturers on (i) strategies for achieving a satisfactory balance between good indoor air quality (IAQ) and the rational use of energy, (ii) guidelines on the use of energy in buildings and IAQ currently available, (iii) significant trends in the building sector with implications for IAQ and energy use and (iv) current research concerns.