Article

Indoor Environment Conditions and Computer Work in an Office

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Abstract

Nineteen employees performing comparable sales order-entry tasks participated in a study of the effects of the environmental conditions at their workstations on their computer work performance. Air temperature, relative humidity, carbon dioxide, total volatile organic compounds, and respirable particulates at 10 microns were logged at each workstation. A web-based software system gathered contemporaneous computer work performance data (correct keystrokes, correction keystrokes, and total mouse clicks). Results showed an effect of day of the week on the correct keystroke rate (p = 0.01) and on the mouse-click rate (p = 0.007) with more being done on Mondays than Fridays and an interaction of workday and air temperature on the correct keystroke rate (p = 0.011) and on the mouse-click rate (p = 0.008). There was an association between air temperature and the correct keystroke rate (p = 0.03); the correct keystroke rate was greater at warmer than cooler temperatures, but there was no significant effect of air temperature on the mouse-click rate. No other IEQ variables exerted significant effects on the computer work performance measures. Findings suggest that the quantity of computer keystroke work is affected by thermal conditions in offices. Future research should investigate whether this result is a direct consequence of thermal conditions or whether temperature is acting as a surrogate for other ventilation performance variables.

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... Although many times being an overlooked factor, extensive research has been conducted proving the impact of thermal comfort on humans. Some studies such as [7] and [8] show the relation between indoor environment conditions and working efficiency or productivity, which have a direct effect on company revenues. ...
... These are expected to be completed with more comfort regulations. Furthermore, as a future work, the EEPSA ontology should not only contain temperature regulations, but also other factors like humidity or air flow, which have been demonstrated to have a direct impact on occupants comfort [8]. ...
... So far, EROSO tackles comfort in workplaces from a thermal (temperature) point of view. However, it has been proved that other factors such as humidity or air flow also affect the indoor comfort [8], so that the solution should be extended to take this factors into account. ...
... Although many times being an overlooked factor, extensive research has been conducted proving the impact of thermal comfort on humans. Some studies such as [7] and [8] show the relation between indoor environment conditions and working efficiency or productivity, which have a direct effect on company revenues. ...
... These are expected to be completed with more comfort regulations. Furthermore, as a future work, the EEPSA ontology should not only contain temperature regulations, but also other factors like humidity or air flow, which have been demonstrated to have a direct impact on occupants comfort [8]. ...
... So far, EROSO tackles comfort in workplaces from a thermal (temperature) point of view. However, it has been proved that other factors such as humidity or air flow also affect the indoor comfort [8], so that the solution should be extended to take this factors into account. ...
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... The journals in which studies were identified cover a wide range of disciplines, such as energy, buildings, environmental engineering, human factors, ergonomics, gerontology, psychology, and neuroscience. Seven publications met the inclusion criteria but were not included in the database, because they did not report sufficient data to perform the estimation of λ % as described in the Methods section, for example, the performance of the participants was measured, but the results were not included in the publication [51,[82][83][84][85][86][87]. [14] 2019 Building and Environment USA 15 120 (1) Metrics of speed were used (2) Metrics of accuracy were used (3) Papers that included more than one study (4) Time in minutes except when indicated (5) Exposure time < 3 hours (6) Estimated based on the following assumption: 8 working hours per day and 5 days per week during 2 weeks. ...
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... Although many times being an overlooked factor, extensive research has been conducted proving the impact of thermal comfort on humans. Haynes (2008) and Hedge and Gaygen (2010) showed the relation between indoor environment conditions and working efficiency or productivity, which have a direct effect on company revenues. Mulville et al. (2016) can have a significant impact on occupants comfort, morale, health and wellbeing in commercial office buildings. ...
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... In particular, much research effort has been expended to show how office spaces affect not just the comfort of workers, but their health and productivity [5,6]. Specifically, research has been useful in illustrating the benefits of appropriate office spaces to both workers' and organisational success [7][8][9]. Overwhelming subjective and objective evidence has proved that the physical environment of an office has significant effects on worker productivity, health, and comfort [6,[10][11][12]. As such, the more time workers spend in the office, the more important it is that the ideal ergonomic and Indoor Environment Quality (IEQ) conditions are provided. ...
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The importance of the office environment to the comfort, productivity and health of workers cannot be overstated. While extant literature has shown that the physical environment of an office has a significant influence on how workers' perform their duties and on their comfort and health, few studies have explored the part played by the length of time they spend in the office. Using our dataset of 5149 workers from across the globe, we investigated the influence of time spent in the office building and at workstations on the relationship between Indoor Environment Quality (IEQ) and workers' productivity, comfort and health. An analysis of variance (ANOVA), Pearson's correlation and multiple regression analyses were employed. Our findings showed that while those who spent less time at work were less influenced by IEQ factors, noise and air quality were predominant in predicting how those who spent more time at work felt about their productivity, comfort and health. Specifically, a relationship did not exist between all of the IEQ factors and their perception of health for workers who spent less time in the office building. Also, the time spent in the office had a greater influence on the relationship between IEQ and workers' comfort than on their productivity and health. Our findings are useful for measures that ensure office workers achieve required work-related tasks under the appropriate working conditions. They give essential insights into the appropriate length of time workers should spend in the office.
... Even though thermal comfort may be overlooked, conducted research proves its impact on humans. Some studies show the relation between indoor envi-ronment conditions and working efficiency or productivity [2,3]. There is also work demonstrating that indoor environment conditions can have a significant impact on occupants comfort, morale, health and wellbeing in commercial office buildings [4]. ...
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Spaces and elements in the built environment have emerged as platforms where materializations of observations and actuations promise to be very profitable. The advent of the Internet of Things (IoT) paves the way to address this challenge but the heterogeneity of the represented knowledge about these artifact systems poses a real problem. Ontologies can be considered as part of the solution to overcome the IoT’s inherent hurdles. A wise option promoted by recent approaches is to design networks of complementary ontologies. However, different points of view are possible and such diversity could lead to interoperability problems. This article advocates for a networked ontology infrastructure conceived on a principled basis guided by documented judicious conceptualizations. In this regard, this survey points towards ontologies involved in conceptualizations of observations and actuations, where the utility of that conceptualization arises when some features of interest need to be observed or acted upon. For each of the reviewed ontologies, their fundamentals are described, their potential advantages and shortcomings are highlighted, and the use cases where these ontologies have been used are indicated. Additionally, use case examples are annotated with different ontologies in order to illustrate their capabilities and showcase the differences between reviewed ontologies. Finally, this article tries to answer two research questions: Is there a firm basis, broadly admitted by the community, for the development of such a networked ontology infrastructure for the observations and actuations in buildings? What ontologies may be considered helpful towards that goal?
... It's important to mention that, according to several studies, human working productivity [14,15], occupant's moral [21] and potential health impairments [25] are in close connection with the thermal comfort. A lack of thermal comfort might cause stress among building occupants. ...
... This corroborates with perspectives from Leaman and Bordass (1999) who argue that "people's perception of control over their environment affects their comfort and satisfaction" (: 4). Hedge & Gaygen (2010) have tested the effects of the IEQ of an airconditioned U.S. sales office on the computer work performance of 19 employees in a one-month long field study. Throughout the duration of the study, the following IEQ variables were monitored: air temperature and RH, CO2, TVOCs and respirable particle matter at 10 microns concentration (PM10), and noise levels. ...
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... These include environmental measures, such as humidity; building factors, such as ventilation rate; workspace factors, such as the presence of Environ Health Perspect DOI: 10.1289/ehp.1510037 Advance Publication: Not Copyedited 5 chemical-emitting materials; and personal factors, such as job stress, allergies, and gender (Mendell 1993;Wargocki et al. 2000;Bornehag et al. 2005;Hedge 2009; Hedge and Gaygen 2010;Nishihara 2014). ...
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... However, recent studies of the Japanese "COOL BIZ" initiative, have shown that 70% of workers report some thermal dissatisfaction and subjectively report reduced productivity (Uchida et al. 2009), suggesting that 28°C (82.4°F) may be slightly too warm, and related Japanese research has shown that an air temperature of 27.3°C (81.1°F) appears to be the best temperature for minimizing energy consumption without adversely affecting office productivity (Tawada et al. 2009). Hedge et al. (2010) have shown that computer productivity can improve in comfortably warm conditions compared to cold conditions indoors in an office. ...
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Certification in the LEED rating system for green buildings traditionally has focused on strategies for increasing energy efficiency and lowering indoor air pollutant emissions by selecting appropriate and natural or recyclable materials. However, designing an energy efficient workplace and low pollution workplace doesn't necessarily equate with creating a healthy and productive workplace. In November 2008 the USGBC introduced 1 credit for good ergonomic design and programs in the Innovation sections of the rating system. This paper outlines the requirements of this ergonomics credit and it presents a case study of a building that has received LEED credit for their successful ergonomics program. Copyright 2010 by Human Factors and Ergonomics Society, Inc. All rights reserved.
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A field study was conducted to investigate the associations between indoor thermal conditions and productivity for computer workers in an insurance company. Thermal environment conditions and productivity were logged every 15 minutes for 9 women workers for 16 consecutive work days. Results showed an association between thermal conditions and productivity, which was highest when conditions fell in a thermal comfort zone and lowest when conditions fell below this zone. The findings have important implications for the design and management of workplaces.
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The indoor temperature can be controlled with different levels of accuracy depending on the building and its HVAC system. The purpose of this study was to evaluate the potential productivity benefits of improved temperature control, and to apply the information for a cost-benefit analyses of night-time ventilative cooling, which is a very energy efficient method of reducing indoor daytime temperatures. We analyzed the literature relating work performance with temperature, and found a general decrement in work performance when temperatures exceeded those associated with thermal neutrality. These studies included physiological modelling, performance of various tasks in laboratory experiments and measured productivity at work in real buildings. The studies indicate an average 2% decrement in work performance per degree C temperature rise, when the temperature is above 25 C. When we use this relationship to evaluate night-time ventilative cooling, the resulting benefit to cost ratio varies from 32 to 120.
Article
A field study of 16 people in a law office was conducted. Environmental conditions, air temperature, relative humidity, carbon dioxide (CO2), respirable particulates at 10 microns (PM10) and total volatile organics (TVOC), at each person's workstation were recorded at one-minute intervals for 4 weeks. Synchronous measures of computer work performance data at minute intervals were logged with a web-based software system. Results showed a contemporaneous effect of temperature on correct keystrokes, CO2 on mouse clicks and of, and one- hour lagged effects of CO2 and PM 10 on correction keystrokes. Findings confirm that the quantity and quality of computer work is affected by environmental conditions.
Article
Theoretical considerations and empirical data suggest that existing technologies and procedures can improve indoor environments in a manner that signifi-cantly increases productivity and health. The existing literature contains moderate to strong evidence that characteristics of buildings and indoor environments significantly influence rates of communicable respiratory illness, allergy and asthma symptoms, sick building symptoms, and worker performance. Whereas there is considerable un-certainty in the estimates of the magnitudes of productivity gains that may be obtained by providing better indoor environments, the projected gains are very large. For the United States, the estimated potential annual savings and productivity gains are $6 to $14 billion from reduced respiratory disease, $1 to $4 billion from reduced allergies and asthma, $10 to $30 billion from reduced sick building syndrome symptoms, and $20 to $160 billion from direct improvements in worker performance that are unre-lated to health. Productivity gains that are quantified and demonstrated could serve as a strong stimulus for energy efficiency measures that simultaneously improve the indoor environment.
Article
Abstract Perceived air quality, Sick Building Syndrome (SBS) symptoms and productivity were studied in an existing office in which the air pollution level could be modified by introducing or removing a pollution source. This reversible intervention allowed the space to be classified as either non-low-polluting or low-polluting, as specified in the new European design criteria for the indoor environment CEN CR 1752 (1998). The pollution source was a 20-year-old used carpet which was introduced on a rack behind a screen so that it was invisible to the occupants. Five groups of six female subjects each were exposed to the conditions in the office twice, once with the pollution source present and once with the pollution source absent, each exposure being 265 min in the afternoon, one group at a time. They assessed the perceived air quality and SBS symptoms while performing simulated office work. The subject-rated acceptability of the perceived air quality in the office corresponded to 22% dissatisfied when the pollution source was present, and to 15% dissatisfied when the pollution source was absent. In the former condition there was a significantly increased prevalence of headaches (P= 0.04) and significantly lower levels of reported effort (P=0.02) during the text typing and calculation tasks, both of which required a sustained level of concentration. In the text typing task, subjects worked significantly more slowly when the pollution source was present in the office (P=0.003), typing 6.5% less text than when the pollution source was absent from the office. Reducing the pollution load on indoor air proved to be an effective means of improving the comfort, health and productivity of building occupants.
Article
A field study of thermal comfort was conducted in Bangkok, Thailand, in which over 1100 office workers responded to a questionnaire while simultaneous physical measurements were taken. In this study we explore whether there is justification for adopting a comfort standard that differs from those developed for office workers accustomed to more temperate climates. Both air-conditioned and naturally ventilated offices were surveyed. Participants cast votes on standard subjective thermal rating scales and these were correlated with temperature indices that variously account for the thermal impacts of humidity, radiant temperature, air velocity, and clothing levels. Following the criteria used in developing a widely adopted thermal comfort standard, it was found that the upper temperature bound for a Thai comfort standard, instead of being the currently accepted level of 26.1 °C for those accustomed to air-conditioning accustomed to naturally ventilated spaces, and as high as 28 °C for those accustomed to air-conditioning. Comparing the responses from the naturally ventilated buildings with both those from the air-conditioned buildings and from studies conducted in the temperate regions provides convincing evidence of acclimatization. These and other findings of this study suggest that interior spaces in Thailand can be cooled to a far lesser degree without sacrificing comfort.
Article
Unlabelled: The main justification for ventilation has historically been to create a healthy indoor environment. Ventilation removes air pollutants originating inside the building, including bio-effluents. The outdoor air supply rate that has been found by experience to provide subjectively acceptable indoor air quality and to prevent the accumulation of moisture in the building is generally sufficient to maintain the concentration of pollutants at healthily low levels. Until 5 years ago this would have been the justification for current ventilation practices, but in 1999 the first of a series of experiments was published, revealing new mechanisms by which raised levels of indoor air pollution may reduce productivity, either in addition to or instead of having negative effects on comfort and health. It was shown in realistic experimental exposures lasting up to 5 h that the performance of simulated office work could be significantly increased by removing common indoor sources of air pollution, such as floor-coverings, used supply air filters and personal computers, or by keeping them in place and increasing the rate at which clean outdoor air was supplied from 3 to 10 to 30 l s(-1) per person. These short-term effects were demonstrated repeatedly even at pollutant levels that had no measurable effects on the perception of air quality by the occupants themselves, although there were effects on subclinical SBS symptoms such as headache. Temperature and noise distraction have since been studied in directly comparable exposures. The prediction arising from these experiments, that the performance of real office work over time would be significantly and substantially affected by the changes in indoor environmental quality that take place in the course of normal building operation, have recently been validated in 8-week field intervention experiments carried out in call-centers in northern Europe and the Tropics. These findings have far-reaching implications for the efficient use of energy in buildings. Practical implications: It has now been shown beyond reasonable doubt that poor indoor air quality in buildings can decrease productivity in addition to causing visitors to express dissatisfaction. The size of the effect on most aspects of office work performance appears to be as high as 6-9%, the higher value being obtained in field validation studies. It is usually more energy-efficient to eliminate sources of pollution than to increase outdoor air supply rates. The experiments summarized in this article have documented and quantified relationships that can be used in making cost-benefit analyses of either solution for a given building. The high cost of labor per unit floor area ensures that payback times will usually be as low as 2 years.
Article
Unlabelled: A 2 x 2 replicated field intervention experiment was conducted in a call-center providing a telephone directory service: outdoor air supply rate was adjusted to be 8% or 80% of the total airflow of 430 l/s (3.5 /h) and the supply air filters were either new or had been in place for 6 months. One of these independent variables was changed each week for 8 weeks. The interventions did not affect room temperature, relative humidity or noise level. The 26 operators were blind to conditions and each week returned questionnaires recording their environmental perceptions and Sick Building Syndrome (SBS) symptoms. Their performance was continuously monitored by recording the average talk-time every 30 min. Replacing a used filter with a clean filter reduced talk-time by about 10% at the high ventilation rate but had no significant effect at the low rate. Increasing the outdoor air supply rate reduced talk-time by 6% with a new filter in place but increased talk-time by 8% with a used filter in place. The interventions also had significant effects on some SBS symptoms and environmental perceptions. The present results indicate that increasing outdoor air supply rate and replacing filters can have positive effects on health, comfort and performance. Practical implications: Supply air filters should be changed frequently not just because their airflow resistance increases progressively but because they degrade air quality with negative consequences for health, comfort and the performance of office work, all of which are factors that affect office productivity (profitability). Increasing outdoor air supply rates may only be beneficial when new filters are installed. Unwanted negative effects may be produced when used filters are in place. Filter condition (used or new) should always be recorded to make it possible to draw sound conclusions in studies of the effects of outdoor air supply rates on building occupants.
Room temperature and productivity in office work. Paper LBNL-60952 A field study of relationship between thermal environment, productivity, and energy consumption in an office
  • O Seppänen
  • W J Fisk
  • Q H Lei
  • T Tawada
  • T Ikaga
  • S Murakami
  • K Kameda
  • H Ueda
Seppänen, O., W.J. Fisk, and Q.H. Lei. 2006. Room temperature and productivity in office work. Paper LBNL-60952, Lawrence Berkeley National Laboratory, Berkeley, CA. Tawada, T., T. Ikaga, S. Murakami, K. Kameda, and H. Ueda. 2009. A field study of relationship between thermal environment, productivity, and energy consumption in an office. Proceedings of Healthy Buildings 2009, Paper 128, 4 pages.