Search results

Occupancy-based lighting control in open-plan office spaces

Lighting accounts for a significant amount of electrical energy consumption in office buildings, up to 45% of the total consumed. This energy consumption can be reduced by as much as 60% through an occupant-dependent lighting control strategy. With particular focus on open-plan offices, where the application of this strategy is more challenging to apply due to differences in individual occupancy patterns, this paper covers (1) to which extent individual occupancy-based lighting control has been tested, (2) developed, and (3) evaluated. Search terms were defined with use of three categories, namely ‘occupancy patterns’, ‘lighting control strategy’, and ‘office’. Relevant articles were selected by a structured search through key online scientific databases and journals. The 24 studies identified as eligible were evaluated on six criteria: (1) study characteristics, (2) office characteristics, (3) lighting system characteristics, (4) lighting control design, (5) post-occupancy evaluation, and (6) conclusions, and this was used to answer the research questions. It was concluded that the strategy has not been tested yet with field studies in open-plan offices, but that it needs further development before it can be applied in these type of offices. Although lighting currently tends to be controlled at workspace level, many aspects of the strategy can be further developed; there is potential to further increase energy savings on lighting within open-plan office spaces. Individual occupancy-based lighting control requires further validation, focussing on the factors influencing its energy savings, on its cost effectiveness, and on its acceptability for users.

Personal lighting conditions of office workers: An exploratory field study

Light enables us to see and perceive our environment but it also initiates effects beyond vision, such as alertness. Literature describes that at least six factors are relevant for initiating effects beyond vision. The exact relationship between these factors and alertness is not yet fully understood. In the current field study, personal lighting conditions of 62 Dutch office workers (aged 49.7 ± 11.4 years) were continuously measured and simultaneously self-reported activities and locations during the day were gathered via diaries. Each office worker participated 10 working days in spring 2017. Personal lighting conditions were interpreted based on four of the six factors (light quantity, spectrum, timing, and duration of light exposure). Large individual differences were found for the daily luminous exposures, illuminances, correlated colour temperatures, and irradiances measured with the blue sensor area of the dosimeter. The average illuminance (over all participants and all days) over the course of the day peaked three times. The analysis of the duration of light exposure demonstrated that the participants were on average only exposed to an illuminance above 1000 lx for 72 minutes per day. The interpretation of personal lighting conditions based on the four factors provides essential information since all of these factors may be relevant for initiating effects beyond vision. The findings in the current paper give first in-depth insight in the possibilities to interpret personal lighting conditions of office workers.

Quality and satisfaction of thermal comfort in Dutch offices

Quality and satisfaction of thermal comfort in Dutch offices

Purpose: This field study analyses the quality of the actual thermal comfort and indoor air quality in Dutch office buildings. A linear regression analysis was used to determine how much these variables and demographic variables influenced the perceived thermal comfort of office workers.Approach: Data were collected on-spot at two Dutch office buildings (n=182) during the winter of 2015 and showed that the indoor air in these offices is of good quality and did not affect the perceived thermal comfort significantly. The indoor temperature was the most important variable that influenced the perceived thermal comfort. Indoor temperatures ranged in this study from 18 till 24oC and were therefore at the edge of acceptable European and Dutch standards NPR-CR 1752 (1999), NEN-EN 15251(2007) and NEN-EN-ISO 7730 (2007).Findings: Office workers which experienced a indoor temperature of 20oC graded this temperature the highest (6.7 on a scale from 1-10). At 20oC the percentage of workers that was dissatisfied was the lowest (30%). This study also showed that female workers were more likely to have the sensation that is was too cold than male workers. European and Dutch standards prescribe that an indoor temperature between 21 and 23oC should be the most ideal temperature during wintertime. This study indicates that an indoor temperature higher than 22oC might be too warm for office workers in The Netherlands during wintertime and that application might influence office workers’ satisfaction negatively.

The office jungle

The Office Jungle is an experimental office environment designed to make offices more "wild". Through this demonstration and associated design vision, we make a first attempt to reflect on and to define what characterizes wildness and how it could empower people in more playful and active lifestyles, particularly in the workplace. In our understanding, wildness is not an exclusive property of nature, but rather a condition that can be designed for. How wildness can be designed is described here in a set of design principles called "Design for Wildness", inspired by the work of Gibson. The Office Jungle, a large geodesic sphere of 2 meters in diameter, is part and parcel of these design principles and can be used as a tool to design other wild environments. Such environments could benefit people working in the office, many of whom have been suffering the consequences of a sedentary lifestyle.

Healing Offices

Een gezond binnenklimaat in kantoorgebouwen leidt tot productiviteitsverhoging en een grotere tevredenheid van werknemers.