Open Office Space Research Articles

Lighting energy consumption in ultra-low energy buildings: Using a simulation and measurement methodology to model occupant behavior and lighting controls

As building owners, designers, and operators aim to achieve significant reductions in overall energy consumption, understanding and evaluating the probable impacts of occupant behavior becomes a critical component of a holistic energy conservation strategy. This becomes significantly more pronounced in ultra-efficient buildings, where system loads such as heating, cooling, lighting, and ventilation are reduced or eliminated through high-performance building design and where occupant behavior-driven impacts reflect a large portion of end-use energy. Further, variation in behavior patterns can substantially impact the persistence of any performance gains. This paper describes a methodology of building occupant behavior modeling using simulation methods developed by the Building Energy Research Center (BERC) at Tsinghua University using measured energy consumption data collected by the University of Washington Integrated Design Lab (UW IDL). The Bullitt Center, a six-story 4831 m2 (52,000 ft2) net-positive-energy urban office building in Seattle, WA, USA, is one of the most energy-efficient buildings in the world (2013 WAN Sustainable Building of the Year Winner). Its measured energy consumption in 2015 was approximately 34.8 kWh/(m2∙yr) (11 kBtu/(ft2∙yr)). Occupant behavior exerts an out-sized influence on the energy performance of the building. Nearly 33% of the end-use energy consumption at the Bullitt Center consists of unregulated miscellaneous electrical loads (plug-loads), which are directly attributable to occupant behavior and equipment procurement choices. Approximately 16% of end-use energy is attributable to electric lighting which is also largely determined by occupant behavior. Key to the building’s energy efficiency is employment of lighting controls and daylighting strategies to minimize the lighting load. This paper uses measured energy use in a 330 m2 (3550 ft2) open office space in this building to inform occupant profiles that are then modified to create four scenarios to model the impact of behavior on lighting use. By using measured energy consumption and an energy model to simulate the energy performance of this space, this paper evaluates the potential energy savings based on different occupant behavior. This paper describes occupant behavior simulation methods and evaluates them using a robust dataset of 15 minute interval sub-metered energy consumption data. Lighting control strategies are compared via simulation results, in order to achieve the best match between occupant schedules, controls, and energy savings. Using these findings, we propose a simulation methodology that incorporates measured energy use data to generate occupant schedules and control schemes with the ultimate aim of using simulation results to evaluate energy saving measures that target occupant behavior.

Using mechanical noise prediction software to provide suitable solutions

Mechanical noise prediction softwares have become a useful tool for consultants to provide noise control recommendations. Two recent projects involving duct breakout will be analyzed to discuss how mechanical noise prediction softwares were used to analyze multiple solutions in order to provide a suitable solution for a medical office building and an open office space.

Acoustics in collaborative open office environments

Historically, acoustical design for open office environments focuses on creating workspaces that maximize speech privacy and minimize aural distractions. Hallmark elements of the traditional open office environment include barriers, sound-absorptive surfaces, and consideration of workspace orientation, size, and background sound level. In recent years, development of “collaborative” office environments has been desired, which creates an open work setting, allowing immediate visual and aural communication between team members. This results in reducing the size of workstations, lowering barriers, and reducing distance between occupants. Additionally, group meeting areas have also become more open, with the popularization of “huddle zones” where small groups hold meetings in an open space adjacent to workstations rather than within enclosed conference rooms. Historically, this type of office environment would have poor acoustical function, with limited speech privacy between workstations and minimal attenuation of distracting noises, leading to occupant complaints. However, these collaborative open office environments function satisfactorily and seem to be preferred by occupants and employers alike. This paper investigates the physical acoustical parameters of collaborative open office spaces.

Predicting public or private feedback-seeking behaviors

Purpose– The purpose of this paper is to examine whether the presence of an audience inhibits or facilitates feedback-seeking behaviors.Design/methodology/approach– A sample of 148 employees completed a survey questionnaire regarding feedback-seeking behaviors. Perceived value of public and private feedback, public self-consciousness (PSC), and tolerance for ambiguity were used to predict public or private feedback-seeking behaviors. Hierarchical multiple regression were used to test the hypotheses.Findings– Statistically significant relationships were found between perceived value of public feedback, PSC, tolerance for ambiguity, and public feedback seeking. Subsequently, statistically significant relationships were only found between perceived value of private feedback, tolerance for ambiguity, and private feedback seeking.Research limitations/implications– Future research should focus on how individuals respond to less privacy in the workplace in regards to feedback-seeking behaviors.Practical implications– Many more companies are moving to open office spaces and cubicles which suggest there is less privacy for employees to seek feedback. This study found that employees do make a distinction when seeking feedback in a public or private context.Originality/value– This is the first field study to identify specific antecedents relating to seeking feedback in a public or private context. With this study, the feedback context becomes another important variable in understanding how an individual's feedback environment may relate to feedback seeking.

Information-theoretic environment features selection for occupancy detection in open office spaces

Knowing the presence or the actual number of occupants in a space at any given time is essential for the effective management of various building operation functions such as security and environmental control (e.g., lighting, HVAC). As occupants “interact” with the indoor environment, they will affect environmental conditions through the emission of CO2, heat and sound, and relatively little effort has been reported in the literature on utilizing this environmental sensing data for occupancy detection. This paper presents the findings of a study to address this question by exploring the most effective environmental features for occupancy level detection. A sensor network with robust, non-intrusive sensors such as CO2, temperature, relative humidity, and acoustics is deployed in an open-plan office space. Using information theory, the physical correlation between the number of occupants and various combination of features extracted from sensor data has been studied. The results show significant correlation between features extracted from humidity, acoustics, and CO2, while little correlation with temperature data. Using features from multiple sensors increases correlation further, and nearly 90% information gain is acquired when nine of the most informative features are combined.

Localized air-conditioning with occupancy control in an open office

Conditioning and ventilating open office spaces requires innovations as new buildings aim to be more intelligent, energy efficient and healthy. This paper explores the possibility of using a localized airflow to divide an open cubicle office into zones without partition walls. Computational fluid dynamics (CFD) model was used to simulate localized airflow in a cubicle office and both the energy and the indoor air quality concerns were addressed. The findings suggest that (1) localized airflow is plausible for zoning purposes, (2) localized airflow can result in both temperature and pollutant concentration segregations, (3) temperature segregations provide possible energy savings if coupled with occupancy-based HVAC control, and finally (4) limited air mixing between zones provide a novel way for better ventilation and indoor contaminant control.

How Much Energy Do Different Toplighting Strategies Save?

Skylights can introduce considerable heat gains and losses that may offset the benefits of electric light savings and cause an increase in yearly net building energy use. The design of a toplight system needs to take into consideration different toplighting types, including aperture size and orientation, electric lighting control, and, most important, the local climate. This study examines the impacts of a variety of toplighting strategies and glazing types on the total yearly energy loads for a prototypical open office space situated in five different climates. Coordinated modeling with both an advanced daylight and electric lighting simulation program and a building thermal simulation program based on hourly weather data for an entire year enable the reliable estimation of annual lighting energy use in response to dynamically changing daylight conditions, and address the interaction between lighting energy and total building energy. This study shows that different toplighting strategies designed to meet...

Company Incentives and Tools for Promoting Telecommuting

The aim of this article is to identify company and employee benefits from telecommuting. Telecommuting implies that a large proportion of the company's office space is unoccupied. To use this efficiently, flexible offices could be introduced in which the employees do not have their own office but use any desk in an open office space. In addition, if telecommuting implies reductions in office space in which employees donate the use of their homes—rent free—to the employer, it is quite fair for the employer to consider returning some of that savings to the telecommuters in compensation for the use of their homes. The results indicate that employees are in fact sensitive to the monetary compensation and that company benefits could be obtained.

Acoustical case studies of three green buildings

Case studies of 3 green buildings with LEED certifications that required extensive acoustical retrofit work to become satisfactory work environments for their intended user groups will be used to define areas where green building design concepts and acoustical design concepts require reconciliation. Case study 1 is an office and conference center for a city environmental education agency. Large open spaces intended to collect daylight through clerestory windows provided large, reverberant volumes with few acoustic finishes that rendered them unsuitable as open office space and a conference room/auditorium. Case Study 2 describes one of the first gold LEED buildings in the southeast whose primary design concepts were so narrowly focused on thermal and lighting issues that they often worked directly against basic acoustical requirements resulting in sound levels of NC 50–55 in classrooms and faculty offices, crosstalk between classrooms and poor room acoustics. Case study 3 is an environmental education and conference center with open public areas, very high ceilings, and all reflective surfaces made from wood and other environmentally friendly materials that result in excessive loudness when the building is used by the numbers of people which it was intended to serve.

Speech privacy between closed and open offices

Speech privacy between closed and open office spaces is dependent on the noise reduction between the spaces, and the background sound available in the receiving space to mask the intruding speech. System performance was evaluated between both pairs of closed spaces, and closed to open space. Ceilings included both light and air supply devices, and the walls included typical door and utility features. The speech privacy was evaluated based upon both objective and subjective measures of performance. The objective response was calculated based on the articulation index (AI), and the subjective response included both PB word lists and continuous discourse (CD). Proper choice of ceiling and wall materials and system design, in combination with electronic masking sound, will provide adequate speech privacy.

The effect of luminaire type and spacing on visibility levels in unobstructed spaces

The authors examine how luminaire type and spacing affect task contrast and visibility levels in unobstructed office spaces. The Lumen-Micro program was used to calculate visibility levels in a model open-office space as a function of luminaire candle-power distribution, fixture spacing, and illuminance level. Three representative luminaires were parametrically examined: a lensed troffer, a high-performance parabolic, and a high-performance uplight. Small differences in average task visibility levels were observed for the different luminaires and fixture spacings examined, but these differences were slight compared with variability within an installation. The study indicates that if one does not know the location of the task a priori, then it is not possible to achieve consistently high visibility levels throughout a space without resorting to lighting solutions that are intrinsically inefficient.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

National Service Center, St. Louis County, Missouri - USA

The new building housing the National Service Center stands in a 40 Ha property in the outskirts of the city and it resembles more a university campus than an administrative centre. The building has only two levels above grade in an attempt to blend into the eminently rural surroundings, avoiding any architectural aggression to the natural environment. With a similar intention, earth hues were used in the precast concrete facade panels finish, completed by the horizontal emphasis of the dark bronze fenestration. Interiorly, the building is outstanding by its flexible arrangement, creating open and integrated office spaces. The modular structure allows for future expansion that will eventually double its present size without affecting its architectural unity.