Indoor Environments & Health in Buildings

Publication Summary

s: Oral Presentations IEQ killer variable number 1: CONTROL! Dr. Atze Boerstra BBA Indoor Environmental Consultancy + Eindhoven University of Technology Centralized indoor climate control seems to be a trend. Two-three decades ago most office workers still were able to directly influence the temperature and air freshness at their workstation e.g. by adjusting the thermostat on their radiator or by opening a window. But nowadays occupants in office buildings (esp. those in open plan offices) more often than not are deprived of control options and exposed to centrally controlled indoor climates designed with ‘average’ comfort needs in mind. This is a problem. Extensive field and lab research has showed that building occupants are more comfortable, have less Sick Building symptoms and are more productive when they have adequate means to fine-tune their thermal environment and local air quality. Therefore class A climates should be defined (e.g. in programs of constraints for new buildings and their building service systems) in terms of optimal control options, not just in terms of temperature bandwidths and minimum air supply. With reference to the outcomes of the PhD study of the author, and with reference to studies from the US, Scandinavia and the UK (e.g. Leaman & Bordass and Humphreys & Nicol), we will argue that (adequate) control (control over indoor climate) should be regarded as killer variable nr. 1. That is, when one wants to guarantee that the end-result is: a healthy, comfortable and the productivity-enhancing office environment. A conceptual model will be presented that describes how available, exercised and perceived control acts as a moderator in the stimulus-response relation between environmental parameters (like air temperature or CO2 concentration) and occupant effects. And specific examples will be given of how not to offer control in office environments (think e.g. of overcomplicated interfaces) and of how to really boost perceived and actual control of building occupants (e.g. with microclimatisation systems). Meta-study on assessing the relationship between IEQ and productivity in office buildings Professor Rajat Gupta* and Dr Adorkor Bruce-Konuah Low Carbon Building Group, Oxford Institute for Sustainable Development, School of Architecture, Oxford Brookes University, Oxford *[email protected] Indoor environmental quality (IEQ) parameters in office buildings have been found to influence workers’ productivity. However majority of studies that have shown increased productivity from improved IEQ have focussed on individual IEQ elements, e.g. temperature or ventilation rates, which is not representative of a real office setting which experiences dynamic conditions where variables such as temperature, relative humidity (RH), ventilation rates, and air pollutants vary across the course of the day. This paper describes meta-analysis of datasets on IEQ and occupant satisfaction surveys gathered through monitoring and Building User Survey (BUS) questionnaires from 21 low energy offices to investigate the influence of perceived indoor environment and control on productivity improvements of occupants in real office settings. The metastudy was conducted as part of Innovate UK’s national Building Performance Evaluation (BPE) programme which undertook case study investigations of 50 low carbon non-domestic buildings. The BPE programme focussed on the buildings’ fabric performance, energy use, environmental conditions and occupant satisfaction. Results show that out of 21 offices, 12 reported an increase in perceived productivity. The maximum increase in productivity was 10% and average was 4.9%. Overall comfort accounted for 72% (r2=0.72) of the variation in perceived productivity, while satisfaction with noise levels was found to have a weak correlation with perceived productivity, explaining only 3% (r2=0.03) of the variation in productivity. Perceived productivity improvement decreased when air was perceived as stuffy and smelly, but surprisingly control over cooling and heating was negatively correlated with perceived productivity, implying that the effect of personal control may be dependent on the environment and the type of activities performed. When occupants were satisfied with temperature (mostly summer), noise, lighting and building features, perceived productivity increased. Insights from the analysis can help in improving (perceived) control of indoor environments as a means for improving productivity in workspaces. Guidance for designers on combined assessment of noise, ventilation and overheating in dwellings Jack Harvie-Clark and Nick Conlan Apex Acoustics & ANC Noise, Vent & Overheating Group The necessity to consider external noise ingress into dwellings typically arises as a Planning requirement. Ventilation is controlled under the Building Regulations, and there is no statutory requirement to consider overheating. However, the Planning system does not ensure that proposed buildings holistically consider insulation against external noise, ventilation and overheating. It is common for the façade sound insulation assessment to barely consider the effect of the ventilation strategy (for example the effect of the quantity of trickle vents required), and there is no general association between ventilation and noise level limits. Similarly, it is common for an overheating assessment, if undertaken, to assume open windows, at the same time that the façade sound insulation assessment assumes closed windows. Where residential developments rely on opening windows to control overheating, there can be a compromise between allowing excessive noise ingress with windows open, or excessive temperatures with windows closed. This problem is exacerbated by the move towards better insulated, more airtight buildings and the need, particularly in urban areas, to consider residential development on noisier sites. A working group has been formed by the Association of Noise Consultants to provide guidance on acoustic conditions and design when considering both the provision of ventilation and prevention of overheating. The guidance produced by the group aims to clarify the conditions that should be considered together, and provide examples of acoustic design solutions. This presentation describes the guide and presents practical methods available to provide ventilation which controls overheating and noise levels without the need to introduce comfort cooling systems. Case studies of projects include passive ventilation systems using attenuated façade vents and methods of using balconies to reduce noise levels incident on open windows. Improving indoor environmental quality and supporting health and wellbeing with indoor plants, green roofs and green walls Dr Lynette Robertson Mackintosh Environmental Architecture Research Unit (MEARU), Mackintosh School of Architecture, Glasgow School of Art, Scotland, UK Plants and vegetative green infrastructure such as green roofs and walls have significant potential for improving the quality of indoor environments and a growing body of research suggests a beneficial effect on the health, wellbeing and productivity of building occupants. This paper provides an overview of the evidence on the key pathways through which vegetation in the environment can help support or enhance human health and wellbeing, and highlights key evidence for: (i) indoor potted plants; (ii) green roofs; (iii) green walls. Potential risks or negative impact on health and wellbeing are also discussed, and how these issues can be managed or overcome. Careful consideration of building characteristics, environmental context and occupant preference is essential in order to make best use of plants and green infrastructure to support human health and wellbeing. Further research is needed to ensure that green infrastructure technologies are sustainable in design and provide multiple environmental benefits. A struggle for 800 ppm Prof Jelle Laverge Department of Architecture and Urban Planning, Ghent University In the spring of 2016, the Belgian national government issued a new royal decree on the environmental conditions of work places. In it, the provisions for ventilation were substantially changed. The previous version of the decree mandated a minimum ventilation rate of 30 m3/h per worker in the space. Since measuring flow or even air exchange rates is not straightforward and therefore, the old decree was hardly ever enforced. Therefore, the new decree opted for a performance based approach, and includes a carbon dioxide concentration threshold value of 800 ppm, based on a best practice review of scientific and occupational health literature. Not only does this bring about a completely new framework for ventilation assessment in Belgium, it also catapults IAQ goals for the Belgian work place to one of the most ambitious set in Europe. Since the introduction of the new decree, a number of very powerful lobby groups, mainly from the construction industry, are working hard to overturn or ‘soften’ the decree. Some of the arguments put forward have merit on principle while others are more opportunistic. These include issues around measuring protocol, issues with transition periods and economical feasibility. In this paper, we will consider some of these arguments and frame them in a scientific and practical background and try to provide a perspective for the further development of this new decree. Evaluation of alternatives to common passive ventilation in home retrofit Oliver Kinnane 1 , Will Turner 2 , Derek Sinnott 3 1 School of Architecture, University College Dublin 2 Electricity Research Centre, University College Dublin 3 Department of the built Environment, Waterford Institute of Technology Passively allowing air movement through the building envelope remains the most common strategy for ventilation provision in UK and Irish homes. Ingress and egress of fresh air through window trickle vents and/