[en] Heat/energy recovery ventilation systems are types of HVAC that can reduce energy consumption and improve the ventilation rate of housing in cold climates. Their performance achieved to date has been inadequate due to equipment failures (freezing of cores, noise, etc.). Freezing of cores is common in extremely cold climates. Single core HRV/ERV units are usually equipped with defrost strategies such as recirculation of exhaust stale air across the heat exchanger and back into the supply air to the house. These defrost strategies can undermine ventilation standards (ventilation rate requirement not being met during recirculation). This paper presents a rigorous investigation on the performance of dual core energy recovery system that provided a continuous ventilation rate at outdoor temperatures below -10°C without frost protection. The dual core ERV had higher apparent sensible effectiveness (up to 12% more) and apparent total effectiveness (up to 9% more) than a conventional single core ERV. It showed no sign of frost problems after four weeks of winter testing, continuously provided outdoor air without stopping to defrost, unlike the conventional single core ERV which required up to 7.5 hours defrosting per day, and also provided a higher supply air temperature (up to 3°C) to indoors with a total whole-house energy saving of 4.7%. (paper)

[en] Singapore is a tropical country that can be affected by outdoor fine particle air pollution. Little information is available on the penetration of outdoor fine particles into daycare environments. Our study attempted to address the following objectives: to measure indoor infiltration factor (F_inf of PM_2.5 from outdoor fine particles and to determine the building parameters that modifies the indoor PM_2.5. We collected indoor/outdoor 1-min PM_2.5. from 50 daycare environments. We noted high indoor and outdoor concentrations of fine particles due to the presence of regional haze pollution. Indoor and outdoor fine particle concentrations are significantly highest for daycares located near highways while indoor to outdoor ratios were significantly lower for air-conditioning use in daycares. Mean F_inf±SD of 0.65±0.19 in daycare rooms which are naturally ventilated and lower F_inf±SD values of 0.46±0.22 for those that are air-conditioned. The penetration coefficients and air exchange rates were higher in naturally ventilated daycares (0.78 vs 0.61 and 1.47 vs 0.86 h⁻¹ respectively). Our findings show that children remaining indoor in daycares where air conditioning is used can reduce PM_2.5 exposures during outdoor pollution episodes. (paper)

[en] The objective of this particular Indoor Health and Productivity (IHP) project is to improve the communication of research findings in the indoor health and productivity area to scientists and building professionals (e.g. architects and engineers) and, thus, to help stimulate implementation of existing knowledge

[en] Low cost, network-based, pervasive sensing devices that capture a range of indoor environmental parameters were successfully developed and deployed in two large mechanically ventilated buildings in Sydney and in Wollongong in Australia. The devices could provide information over the internet for the indoor environment of the buildings at high spatial and temporal resolutions and could also capture occupant expressions of preferences for the indoor thermal environment. The paper describes findings from the monitoring data and the real-time occupant responses that were collected between March/2017 and October/2018. The analysis includes records from approximately 1450 real-time expressions of thermal preferences from the occupants of the two buildings and more than 5.5 million time stamp rows that contained sets of indoor environmental quality data. The paper demonstrates a low-cost method for benchmarking buildings with each other and providing the means of communicating the often-unknown occupant requirements to facility managers. (paper)

[en] Within the framework of 'Greater Rhone Delta Program', a comparative risk assessment study has been carried out for several years. The aim of this project is to compare, on a regional scale, the effect of pollution on the population. In this paper, we focus on pollution issued from residential heating; and we compare it with those resulting from the generating cycle which has been studied in a previous work. The census of the overall population dwellings has been taken as well as the heating type of installations and the fuel consumption (wood, coal, oil, gas). These data are obtained from national or specific sources. Fuel consumption has been characterized for the 19 districts constituting the region. The 'emission factors' ensue from consumption and fuel specificity. For this purpose, the 'region' has been split up into 1,133 'meshes' of 100 km². Each of them acts as one source. The 'region' is covered by sixteen meteorological stations which provide data for the simplified atmospheric transfer model which calculates concentrations in each 'mesh'. The mean annual concentrations of pollutants in each 'mesh' for households and the generating cycles are compared. It can be seen that residential pollution is greater than those issued from the generating and refinery cycles although about one third of the oil processed in France is trans- formed in this region. Residential pollution, being as important as many other types of pollution, must be included in every study dealing with environmental pollution. (author)

[en] After the nuclear reactor accident of Chernobyl, the 'Integrated Measurement and Information System (IMIS) for Monitoring the Environmental Radioactivity and Detecting Emissions from Nuclear Plants was implemented in Germany. IMIS is a nationwide comprehensive measuring system which permanently monitors the radioactivity in all important environment media in the whole federal territory. At approximately 40 sites, the activity concentration of radioactive substances is measured in air and precipitations. At least 14 of them are responsible for trace monitoring of radionuclides in the air. The legal bases of IMIS prescribe regular inter-laboratory comparison analyses in cooperation with the Physikalisch-Technische Bundesanstalt (PTB), with the use of reference materials prepared by the Federal Coordinating Laboratories. In order to fulfil this requirement in the field of trace survey measurements in ground-level air, the Federal Office for Radiation Protection ('Bundesamt fuer Strahlenschutz', BfS) and the PTB have conducted a comparison with real, dust-loaded reference filters in 2005. The comparison was organized within the framework of a cooperation of trace survey stations from Austria, Germany and Switzerland. The paper describes the preparation of the real, dust-loaded reference filters, the procedure for spiking the filters with the activity standard solution containing ²²Na, ⁸⁸Y, ⁸⁹Sr, ⁹⁰Sr, ¹²⁵Sb, ¹³³Ba, ¹³⁴Cs, and ²⁴¹Am. Some results are discussed and conclusions are given

[en] A review on specific parameter measurements to calculate doses per unit of incorporation according to recommendations of the International Commission of Radiological Protection has been performed for inhaled actinide oxides. Alpha activity distribution of the particles can be obtained by autoradiography analysis using aerosol sampling filters at the work places. This allows us to characterize granulometric parameters of 'pure' actinide oxides, but complementary analysis by scanning electron microscopy is needed for complex aerosols. Dissolution parameters with their standard deviation are obtained after rat inhalation exposure, taking into account both mechanical lung clearance and actinide transfer to the blood estimated from bone retention. In vitro experiments suggest that the slow dissolution rate might decrease as a function of time following exposure. Dose calculation software packages have been developed to take into account granulometry and dissolution parameters as well as specific physiological parameters of exposed individuals. In the case of poorly soluble actinide oxides, granulometry and physiology appear as the main parameters controlling dose value, whereas dissolution only alters dose distribution. Validation of these software packages are in progress. (author)

[en] The topics discussed in this paper are accept that SBS (Sick building syndrome) is a reality ; understand the dimensions of the problem ; differentiate between sick building syndrome and building related illness ; introduce standards ; understanding the economics ; act pro-actively not re-actively

[en] This study investigates the thermal comfort and indoor air quality performance of Active Chilled Beams (ACB) in cooling operation mode in an open office environment with asymmetrical loads. Many studies on thermal comfort using ACB in cooling mode have been conducted; most of the studies confirm that thermal comfort is satisfactory because the temperature gradient and the airspeeds are acceptable at the occupant level. However, these studies do not specifically address the local discomfort in cooling mode. Furthermore, these studies do not consider performance under different ACB configurations or varied boundary conditions such as those found in real offices. This paper reports the results of an experimental study that addresses the above issues. A laboratory experiment was designed to simulate a multi-occupant open office with an ACB subjected to asymmetric boundary conditions. The results demonstrate that discomfort draft risk at the ankle level is higher when the ACB is oriented parallel to the window. Furthermore, the results suggest that shape (the type of ACB) and throw of ACB affect air distribution. The results emphasize the importance of properly selecting, orienting, and designing ACB, not just to offset the room loads, but to match the proportions and boundary conditions of the office. (paper)

[en] Vapour intrusion (VI) can pose a human health risk concern to occupants of buildings overlying volatile organic contaminant (VOC) contamination in soil or groundwater. VI assessment has conventionally focused on measuring exposure point concentrations in indoor air (IA). Measured IA concentrations, however, are difficult to definitively ascribe to VI because of temporal and spatial variability in the measured concentrations and the contribution of background sources to IA at levels that can exceed current screening levels. Determining the contribution of the VI pathway to IA often warrants the investigation of sub-slab (SS) concentrations to demonstrate a complete VI pathway from SS into IA. In our experience, VI assessments consisting of only SS and IA results often do not produce a definitive decision (either mitigation or no further assessment). More often SS and, in particular, IA concentrations are slightly above or slightly below current screening levels resulting in additional sampling activities being required. (author)