Occupant productivity and office indoor environment quality : a review of the literature

The purpose of this paper is to review the existing literature to draw an understanding of the relationship between indoor environmental quality and occupant productivity in an office environment. The study reviews over 300 papers from 67 journals, conference articles and books focusing on indoor environment, occupant comfort, productivity and green buildings. It limits its focus to the physical aspects of an office environment. The literature outlines eight Indoor Environmental Quality (IEQ) factors that influence occupant productivity in an office environment. It also discusses different physical parameters under each of the IEQ factors. It proposes a conceptual model of different factors affecting occupant productivity. The study also presents a review of the data collection methods utilised by the research studies that aim to investigate the relationship between IEQ and occupant productivity. The study presents a comprehensive discussion and analysis of different IEQ factors that affect occupant productivity. The paper provides a concise starting point for future researchers interested in the area of indoor environmental quality

Researchers study role of lighting control systems in saving energy

Aussi disponible en fran\ue7ais: Des chercheurs \ue9tudient l'impact des syst\ue8mes de r\ue9gulation de l'\ue9clairage sur les \ue9conomies d'\ue9nergiePeer reviewed: NoNRC publication: Ye

Window shadings reduce residential cooling energy

This article presents results of experiments at the Canadian Centre for Housing Technology comparing the performance of two types of window shadings for houses: exterior rollshutters and interior blinds.Cet article pr\ue9sente les r\ue9sultats d?exp\ue9riences men\ue9es au Centre canadien des technologies r\ue9sidentielles, ayant pour objet de comparer la performance de deux (2) types de stores ou toiles pour fen\ueatres r\ue9sidentielles : \ue0 volet roulant pour ext\ue9rieur et \ue0 enroulement automatique pour int\ue9rieur.Aussi disponible en fran\ue7ais: Des pare-soleil pour r\ue9duire l?\ue9nergie de refroidissement de votre maisonPeer reviewed: NoNRC publication: Ye

Understanding how daylight-linked lighting systems actually perform in buildings

Aussi disponible en fran\ue7ais: \uc9tude sur la performance des syst\ue8mes d'\ue9clairage automatique combin\ue9s \ue0 la lumi\ue8re du jourPeer reviewed: NoNRC publication: Ye

Let there be light : the impact of window blinds on daylight-linked dimming and automatic on/off lighting controls

Studies have shown that daylight-linked lighting control systems such as automatic on/off and continuous dimming have the potential to reduce the electrical energy consumption in office buildings by 30 to 60%. However, in practice, most daylight-linked systems installed in buildings do not provide the anticipated energy savings. Window shades used for sun shading and glare control impact the energy performance of these systems. Projected energy savings are reduced by occupants changing the position of the blinds when direct sunlight reaches their work area, but seldom resetting the blinds for useful daylight admittance after the unwanted conditions diminish. Leaving the blinds closed unnecessarily reduces the amount of daylight available at the photosensor and prevents the photocontrolled lighting systems from achieving maximum energy savings. Photocontrolled blinds can reduce the limitations of manually operated blinds by closing automatically when the interior has too much glare or is too hot, and re-opening later to admit useful daylight.Des \ue9tudes ont montr\ue9 que les syst\ue8mes de commande d'\ue9clairage li\ue9s \ue0 la lumi\ue8re du jour, tels que la mise sous ou hors tension automatique et la gradation continue, peuvent faire r\ue9duire la consommation d'\ue9nergie \ue9lectrique dans les immeubles de bureaux de 30 \ue0 60 %. Cependant, dans la pratique, la plupart des syst\ue8mes de ce type install\ue9s dans les b\ue2timents ne donnent pas les \ue9conomies d'\ue9nergie attendues. Les stores utilis\ue9s comme pare-soleil ou pour prot\ue9ger contre l'\ue9blouissement ont une incidence sur leur efficacit\ue9 \ue9nerg\ue9tique. Les \ue9conomies d'\ue9nergie pr\ue9vues sont r\ue9duites par les occupants qui modifient la position des stores lorsque la lumi\ue8re du soleil frappe directement leur aire de travail, mais r\ue8glent ensuite rarement les stores pour laisser entrer la lumi\ue8re du jour utile apr\ue8s que les conditions non d\ue9sir\ue9es aient diminu\ue9. Le fait de laisser les stores ferm\ue9s sans raison valable r\ue9duit la quantit\ue9 de lumi\ue8re du jour disponible au niveau du photod\ue9tecteur et emp\ueache les syst\ue8mes d'\ue9clairage command\ue9s par d\ue9tecteur optique de produire les \ue9conomies d'\ue9nergie maximales. Les stores command\ue9s par d\ue9tecteur optique peuvent r\ue9duire les limitations des stores \ue0 commande manuelle en se fermant automatiquement lorsque la chaleur ou l'\ue9blouissement \ue0 l'int\ue9rieur est trop intense et en rouvrant plus tard pour laisser entrer la lumi\ue8re du jour utile.Peer reviewed: NoNRC publication: Ye

METHODOLOGY TOWARDS DEVELOPING SKYLIGHT DESIGN TOOLS FOR THERMAL AND ENERGY PERFORMANCE OF ATRIUMS IN COLD CLIMATES

This is one of two papers that outlines the methodology used to develop, through computer simulation, skylight design tools for thermal and energy performance of atriums in cold climates. The methodology identified important design alternatives that included skylight and atrium physical variables, and a series of thermal and energy performance outputs that may serve as selection criteria for an energy-efficient design. New prediction models were developed to overcome some computer-simulation limitations, which included models to deal with airflow between an atrium and its adjacent spaces and temperature stratification within an atrium space. The developed airflow network model is a technique used to predict the mutual influence between the atrium and its surrounding spaces without requiring additional geometrical information on the surrounding spaces. The developed temperature stratification model is consistent with airflow network models and the zone concept used in building thermal-simulation programs since it takes into account radiation (overlooked in airflow network models) and convection heat transfer at the same time. This was done through treating fictitious surfaces that separate the thermal zones in a similar way as real surfaces. Fictitious surfaces were assigned a high emissivity, high solar transmittance, high thermal conductivity and convection film coefficient of 10 W/m C. These values were found to yield reasonable solar radiation absorption, convection and radiation heat balances for the real surfaces irrespective of the number of the thermal zones. The developed models were integrated into a simulation computer program, and then validated against field measurements of a case study atrium. The predicted indoor temperatures were within 2C of the measur..

Occupant preferences and satisfaction with the luminous environment and control systems in daylit offices: a literature review

This paper presents an overview of peer-reviewed investigations of subjective issues linked to the use of daylighting in office buildings, particularly studies of preferred physical and luminous conditions in daylit office environments, and studies of occupant satisfaction and acceptance of electric lighting and window shading controls. The literature shows a consistent strong preference for daylight and a wide distribution between individuals in relation to the preferred illuminance levels in daylit offices. Existing knowledge about how people respond to daylight-linked lighting and shading controls in the workplace is very limited; therefore, this paper presents a summary of knowledge gaps in the field of daylighting and its interaction with the occupants. The resulting key directions for future research highlight issues for which a better understanding is required for the development of lighting and window shading control systems that are both energy efficient and suitable for the office occupants.Ce document pr\ue9sente un aper\ue7u de l'examen par des pairs de questions subjectives soulev\ue9es \ue0 propos de l'\ue9clairage naturel dans les \ue9difices \ue0 bureaux, plus particuli\ue8rement des \ue9tudes sur les pr\ue9f\ue9rences en mati\ue8re d'environnement physique et de luminosit\ue9 dans le milieu de travail, ainsi que des \ue9tudes sur la satisfaction des travailleurs et l'acceptation des syst\ue8mes de commande automatique de l'\ue9clairage \ue9lectrique et des stores dans les bureaux utilisant l'\ue9clairage naturel. La documentation fait \ue9tat d'une pr\ue9f\ue9rence marqu\ue9e pour la lumi\ue8re du jour et de pr\ue9f\ue9rences personnelles partag\ue9es quant \ue0 l'intensit\ue9 lumineuse dans les bureaux utilisant l'\ue9clairage naturel. On en conna\ueet bien peu sur la r\ue9action des travailleurs \ue0 l'\ue9clairage naturel et aux syst\ue8mes de commande des stores dans les bureaux. Aussi ce document r\ue9sume-t-il les lacunes dans le domaine de l'\ue9clairage naturel et de l'interaction qu'il exerce sur les occupants des \ue9difices \ue0 bureaux. Il en r\ue9sulte que les recherches devront s'orienter sur les questions qui \ue9chappent encore \ue0 notre compr\ue9hension, de mani\ue8re \ue0 mettre au point des syst\ue8mes de commande des stores qui soient efficaces sur le plan \ue9nerg\ue9tique et qui conviennent aux occupants des bureaux.Peer reviewed: YesNRC publication: Ye

Effective solar shading devices for residential windows save energy and improve thermal conditions

In this article we present research on the thermal effects of shading devices in cold-climate houses, which we hope will provide valuable supplemental information to the lighting designer. In Canada, the energy demand for residential heating and cooling accounts for 62% of the total energy of average homes. Although the overall cooling energy demand is much lower than that for heating, some highly-populated areas experience a peak demand for electricity on summer afternoons. Effective solar shading devices such as exterior movable insulating shutters and interior highly-reflective shades may reduce residential energy demand for heating and cooling and improve thermal conditions near windows.On pr\ue9sente dans cet article une recherche portant sur les incidences thermiques des dispositifs de contr\uf4le d?admission de la lumi\ue8re du jour dans les maisons des climats froids. Cette recherche, nous l?esp\ue9rons, procurera aux concepteurs d?\ue9clairages une source d?information suppl\ue9mentaire pr\ue9cieuse. Au Canada, la demande d?\ue9nergie pour r\ue9pondre aux besoins en chauffage et en climatisation r\ue9sidentiels repr\ue9sente 62 % de la consommation \ue9nerg\ue9tique totale des maisons moyennes. Bien que la demande d?\ue9nergie globale pour la climatisation soit de beaucoup inf\ue9rieure \ue0 celle pour le chauffage, certaines r\ue9gions \ue0 forte densit\ue9 de population connaissent des pointes de demande d?\ue9lectricit\ue9 durant les apr\ue8s-midis d?\ue9t\ue9. Des dispositifs de contr\uf4le d?admission de l?ensoleillement efficaces, tels que les contrevents isolants ext\ue9rieurs orientables et les stores int\ue9rieurs hautement r\ue9fl\ue9chissants peuvent contribuer \ue0 r\ue9duire la demande r\ue9sidentielle en \ue9nergie pour le chauffage et la climatisation, et am\ue9liorer en outre les conditions de confort thermique \ue0 proximit\ue9 des fen\ueatres.Peer reviewed: NoNRC publication: Ye