schools

Windcatchers are roof mounted devices that use the action of the wind to provide top down natural ventilation to a room. Here, fresh air is channelled into a room while, at the same time, stale air is drawn out. This provides a simple but attractive natural ventilation methodology that is increasing in popularity in U.K. schools. However, an analysis of system performance has largely been limited to laboratory based measurements and the use of CFD to generate predictions.

The present paper aims at investigating the indoor air quality in fifteen school buildings located in the greater Athens area. Experimental investigations were performed in fifteen different school classrooms and the concentration levels of various pollutants such as CO2, CO, TVOC, HCHO, and radon, were measured. Moreover, the experimental investigation included measurements of several environmental parameters such as temperature, relative humidity and air velocity inside each classroom, while ventilation was examined by estimating the air changes using the tracer gas technique.

Radon gas is now considered to be a health hazard when found in excessive amounts in the builtenvironment. The levels of radon vary greatly, with some geographical areas having very highlevels. In the United Kingdom, Northamptonshire was declared an Affected Area in 1992, and itwas at this stage that our group first started studying radon levels and the steps taken to reducethem.The radon levels both before and after remediation were studied, together with the number ofoccupants of affected rooms, and their pattern of occupation.

This paper describes a series of field measurements investigating the ventilation rates and indoor airquality in four newly built secondary schools in England. In these schools each with a differentventilation strategy - measurements and calculations were performed to determine the variation inventilation rates during the school day. All the schools were assessed for compliance with the recentlyadopted Building Bulletin 101 which defines the set of criteria in relation to the ventilation rates andindoor air quality in new school buildings.

In this paper air distribution solutions aiming to lower air velocities and good temperature control arestudied by measurements in 6 schools and temperature simulations. Air velocity measurementsshowed good performance of duct and ceiling diffusers which provided maximum velocities less than0.2 m/s and can be highly recommended for classrooms. The wall diffusers were clearly not suitable forclassrooms due to high velocities up to 0.43 m/s.

Seven schools underwent an energy audit, evaluating the existing situation through measurement and simulation and looking to possible retrofit measures and their economic feasibility with the energy performance tool (EPB) as an instrument. The results are troubling. The seven schools audited are all problem buildings: hardly any insulation, windows quite air leaky, central heating systems poorly designed and no usage of an on purpose installed ventilation system.

In the following, measurements of CO2 levels in seven classrooms in four schools are reported. Measurements were taken for approximately one week in each classroom during the heating season and the time-varying ventilation rates estimated. The results of the experiments show CO2 concentrations which are far beyond the guideline value of 1000 ppm (the average concentration during the occupied period was 1957 ppm). In some classrooms the level exceeded the range of the detector (4000ppm).

This paper summarizes baseline results from the U.S. Environmental Protection Agency's (EPA) school demonstration studies. Indoor pollutants of concern were formaldehyde, sum of targeted volatile organic compounds o:VOC), carbon monoxide (CO), particulate matter less than 2.5 microns (PM2.5), particulate matter less than 10 microns (PM10), and bioaerosols (bacteria, fungi, and thermophiles). The five schools presented here had no significant indoor air quality problems. Locations of these schools were distributed throughout various climate zones in the United States.

The aim was to develop a simple dynamic model for predicting air exchange caused by short time single-sided ventilation and necessary window opening time in classrooms. Tracer gas measurements have been made in a full-scale room. The comparison indicates that the model can be used when rough estimates of air exchange are of interest.

The association of moisture damages of school buildings with microbial indoor air quality and health status of school children was studied. To determine the association the school buildings (N=32) were divided into the moisture damaged (index) and non-damaged (reference) schools according to technical inspection data. Children's health surveys were made by questionnaires. Microbes were determined from indoor air of school buildings using a six-stage impactor. Children in the index schools reported more respiratory symptoms compared to children in the reference schools.