Occupied Buildings Research Articles

Bioclimatic vs conventional building: experimental quantification of the thermal improvements

This paper focuses on the thermal comparison between two full-size occupied buildings located in Madrid, built considering different constructive criteria. Hourly temperature distributions have been calculated during the working timetable to assess indoor dynamic processes. In both cases there are less than 4% of outliers, reaching lower standard deviations in the bioclimatic offices. Temperature oscillations have shown different thermal profiles depending on the user's behavior. High percentages of neutral sensation and low values of people dissatisfied have been obtained. The bioclimatic building has obtained higher comfort measures as a function of the thermal balances and the global primary energy consumption.

ASSESSMENT OF EFFECTIVE ENERGY RETROFIT STRATEGIES AND RELATED IMPACT ON INDOOR ENVIRONMENTAL QUALITY

1.0. INTRODUCTION In the United States, K–12 school buildings spend more than $8 billion each year on energy—more than they spend on computers and textbooks combined [1]. Most occupied older buildings demonstrate poor operational performance—for instance, more than 30 percent of schools were built before 1960, and 53 percent of public schools need to spend money on repairs, renovations, and modernization to ensure that the schools' onsite buildings are in good overall condition. And among public schools with permanent buildings, the environmental factors in the permanent buildings have been rated as unsatisfactory or very unsatisfactory in 5 to 17 percent of them [2]. Indoor environment quality (IEQ) is one of the core issues addressed in the majority of sustainable building certification and design guidelines. Children spend a significant amount of time indoors in a school environment. And poor IEA can lead to sickness and absenteeism from school and eventually cause a decrease in student performance [3]. Different building types and their IEQ characteristics can be partly attributed to building age and construction materials. [4] Improving the energy performance of school buildings could result in the direct benefit of reduced utility costs and improving the indoor quality could improve the students' learning environment. Research also suggests that aging school facilities and inefficient equipment have a detrimental effect on academic performance that can be reversed when schools are upgraded. [5] Several studies have linked better lighting, thermal comfort, and air quality to higher test scores. [6, 7, 8] Another benefit of improving the energy efficiency of education buildings is the potential increase in market value through recognition of green building practice and labeling, such as that of a LEED or net zero energy building. In addition, because of their educational function, high-performance or energy-efficient buildings are particularly valuable for institution clients and local government. More and more high-performance buildings, net zero energy buildings, and positive energy buildings serve as living laboratories for educational purposes. Currently, educational/institutional buildings represent the largest portion of NZE (net zero energy) projects. Educational buildings comprise 36 percent of net zero buildings according to a 2014 National New Building Institute report. Of the 58 net zero energy educational buildings, 32 are used for kindergarten through grade 12 (K–12), 21 for higher education, and 5 for general education. [9] Finally, because educational buildings account for the third largest amount of building floor space in the United States, super energy-efficient educational buildings could provide other societal and economic benefits beyond the direct energy cost savings for three reasons: 1) educational buildings offer high visibility that can influence community members and the next generation of citizens, 2) success stories of the use of public funds that returns lower operating costs and healthier student learning environments provide documentation that can be used by others, and 3) this sector offers national and regional forums and associations to facilitate the transfer of best design and operational practices.

A comprehensive approach to API RP 752 and 753 building siting studies

Facility siting studies are an important part of process safety, and are required for facilities that fall under OSHA’s PSM program. Facility siting is frequently interpreted as performing a building siting study which adheres to the guidance given in API RP 752. Building siting may also consider siting of temporary or portable buildings based on the guidance in API RP 753. While both API RP 752 and API RP 753 provide a framework and some guidance for performing building siting studies, they do not provide detailed methodologies or provide guidance on performing a detailed analysis. As a result many building siting studies are inconsistent in their overall approach, or in the way they address hazards. Due to the recent scrutiny applied to building siting studies, more attention has been given to provide evaluations which correctly describe the range of hazards that may affect an occupied building at a petrochemical facility. This paper outlines a comprehensive methodology for performing building siting studies at such facilities. The methodology addresses the applicable hazards and the available tools by which the potential impacts to building occupants can be evaluated.

In-use office building energy characterization through basic monitoring and modelling

Due to the European Union energy reduction strategy, many in-use buildings will be energetically monitored in the coming years to obtain their main thermal characteristics to improve or prove their energy efficiency. This is difficult to do with a reduced set of sensors and a robust data analysis methodology. This paper is focused on proposing some modifications on the existing ISO 9869 method and co-heating method to make them usable with basic energy monitoring data of in-use buildings and obtain their main thermal characteristics: the Heat Loss Coefficient (HLC considers heat losses through envelope plus infiltration) and the solar aperture (Sa or gA-value) of the whole building.Under the FP7 project A2PBEER an occupied big office building has been energetically monitored. This monitoring system has been designed and installed while the building was in operation. Using this monitored data a modified ISO 9869 method has been applied to some specifically selected cloudy and cold winter periods to obtain the HLC of the building. Taking this HLC as a reference, a modified co-heating method has been used to estimate both the HLC again and the Sa of the whole building. Although monitoring was carried out under very difficult conditions since the building was occupied, the proposed modifications on those two existing methods have delivered very reliable results with these two Key Performance Indicators (HLC and Sa) of the building under real operation conditions.

Venturing deep into high right-bank slide of river Ganges near Chandernagore Strand, in Hooghly, India

Two multi-storied occupied apartment buildings and a clinic of ‘ Red-Cross Society’ in Chandernagore-a former French colony, located very close to the banks of tidal river ‘ Hooghly’ (-the southernmost part of River Ganges- the major hydrodynamic system that formed the world's largest delta) are standing precariously, following some recurrent slides of high river-bank during the last year’s monsoons. The area where the ground caved in, is on the end of the famous Strand Bank Road (in Hooghly district of West Bengal in India); which is supposed to be the best decorated bank of the river ‘ Ganges’ along its entire length of 2500 km. The opposite river bank is an official sand mining site. The river over considerable stretch at both upstream and downstream apparently seemed stable when analyzed over an extensive temporal domain from old Survey of India toposheets, recent satellite imagery, digital elevation model, field hydrographical survey synthesized in Geographical Information System (GIS) platform. A closer look into the geotechnical aspects supported by subsurface exploration, post failure on-site exposures and stability analysis revealed certain startling facts when considered in association with the hydro-meteorological factors and fluvial dynamics. An in-depth study of the factors responsible for the localized erosion is presented based on site observations and evidences, analyzed in association with real time hydrological and meteorological data.

ACMV Energy Analysis for Academic Building: A Case Study

Building energy audit examines the ways actual energy consumption is currently used in the facility, in the case of a completed and occupied building and identifies some alternatives to reduce current energy usage. Implementation of energy audit are practically used to analyze energy consumption pattern, monitoring on how the energy used varies with time in the building, how the system element interrelate, and study the effect of external environment towards building. In this case study, a preliminary energy audit is focusing on Air-Conditioning & Mechanical Ventilation (ACMV) system which reportedly consumed 40% of the total energy consumption in typical building. It is also the main system that provides comfortable and healthy environment for the occupants. The main purpose of this study is to evaluate the current ACMV system performance, energy optimization and identifying the energy waste on UTeM's academic building. To attain this, the preliminary data is collected and then analyzed. Based on the data, economic analysis will be determined before cost-saving methods are being proposed.

Developing Life-Cycle Environmental Response Costs for Leaking Underground Storage Systems at Service Station Sites

Leaking underground storage tank systems at service stations have resulted in tens of thousands of petroleum releases and associated groundwater chemical plumes often extending hundreds of feet off-site. Technical and engineering approaches to assess and clean up releases from underground tanks, product lines, and dispensers using technologies such as soil vapor extraction, air sparging, biostimulation, and monitored natural attenuation are well understood and widely published throughout the literature. This article summarizes life-cycle environmental response costs typically encountered using site-specific cost estimation or metric-based cost categories considering the overall complexity of site conditions: (1) simple sites where response actions require smaller scale assessments and/or remediation and have limited or no off-site impacts; (2) average sites where response actions require larger scale assessments and/or remediation typical of petroleum releases; (3) complex sites where response actions require greater on-site and/or off-site remediation efforts; and (4) mega sites where petroleum plumes have impacted public or private water supplies or where petroleum vapors have migrated into occupied buildings. Associated cleanup cost estimates rely upon appropriate combinations of individual work elements and the duration of operation, maintenance, and monitoring activities. These cost estimates can be offset by state reimbursement funds, coverage in purchase agreements, and insurance policies. A case study involving a large service station site portfolio illustrates the range of site complexity and life-cycle environmental response costs. © 2014 Wiley Periodicals, Inc.

Development and validation of a gray box model to predict thermal behavior of occupied office buildings

Due to the development of energy performance contracting and the needs for peak electric demand reduction, the interest for building energy demand prediction is renewed. Gray-box models are a solution for energy demand prediction. However, it is still difficult to find the best level of model complexity and the good practices for the training phase. Since models’ order and parameter identification method have a strong impact on the forecasting precision and are not intuitive, a comparative design approach is used to find the best model architecture and an adequate methodology for improving the training phase. The gray box models are compared on their ability to forecast heating and cooling demands and indoor air temperature. An objective function is proposed aiming to minimize both power and indoor temperature prediction errors. Moreover, for each model, several training period durations are tested. First, this study shows that a R6C2 (second order model) model is adapted to predict the building thermal behavior. Furthermore, the best fits are obtained with two weeks of data for the identification process. Second, a sensitivity analysis using total Sobol index calculation leads to validate the objective function and identify the most important parameters for prediction.

Assessment of the dynamic thermal performance of massive buildings

The aim of this paper is the evaluation of the thermal behavior of a massive building under the synergic combination of natural ventilation and thermal inertia. In particular, an experimental study has been carried out on Villa San Saverio, which is a massive historical building located in Catania (Italy), in order to characterize its thermal performance under dynamic conditions, and to evaluate the potential decrease of the indoor overheating by exploiting natural ventilation and limiting both internal and solar gains.The analysis of the transient behavior of this building permits to highlight the possibility of diversifying the time lag in relation to the wall orientation. A time lag of 12.00–14.00h can be suggested for the walls due East. On the other hand, a time lag of around 8.00h can be suggested to achieve the same result for the walls due West.Time lags higher than the values suggested above could be not fully functional, since delaying further the heat transfer from the wall to its inner surface, reduces the useful time for exploiting the cooling effect of the nocturnal ventilation.The results of both measurements and simulations indicate that high thermal inertia mass combined with natural ventilation prevents phenomena of overheating and ensures good comfort levels in occupied buildings, reducing the needs of cooling systems during summer period.

Modeling of indoor air particles with resuspension for an occupied commercial building

As people spend most of their time indoors, identifying pollutant concentration in indoor air is important for examination of human exposure. Resuspension via human activity is known as a significant source of particulate matter in indoor air. In this study, a model was developed to predict concentration of indoor particles in an occupied commercial building. The model considers resuspension from human activity and number of people in each targeted area. A materials balance method was used to calculate the concentration for each particle size bin. Population in each room was counted from entry and exit data of employees. Optical particle counters measured particle concentration in modeled area. Results from the model simulation were compared with measured concentrations and showed good agreement.

Configuring wall layers for improved insulation performance

External walls provide an important barrier between occupied building spaces and variable ambient conditions. Building insulation is often optimized for static performance based on its R-Value rating, but a growing body of literature has begun to assess the dynamic thermal performance of multi-layer walls. The focus of this work is to provide fundamental insight into configuring wall layers for improved insulating performance. Thirty-three different walls are evaluated based on four primary configurations with fixed volumes of insulation and thermal mass. Only the layer distribution is varied. Because the total volume of each material is fixed, the overall thermal resistance and capacitance are equivalent for all configurations studied. An electrical analogy is used to model the one dimensional heat conduction through the wall and determine the magnitude ratio and phase of the frequency response evaluated at the frequency corresponding to a period of 1day. The two temperatures used to quantify the wall system transfer function are the inside and outside surfaces of the wall (i.e., two surfaces exposed to the indoor and outdoor environments, respectively). The best insulating performance is achieved when insulation layers are positioned as close as possible to the inside and outside layers of the wall (i.e., near the indoor and outdoor environments). In addition, optimal results occur when both the insulation and thermal mass are distributed evenly throughout the wall. Using this optimized configuration, each material is then divided into an increasing number of thinner layers. Results indicate that an optimum number of layers exist such that the magnitude ratio is maximized.

Economic and management perspectives on control of illegal land uses in the leasehold system

PurposeIllegal changes of use in aged industrial and residential buildings is now a prevalent problem in Hong Kong. This research aims to develop a strategy for an effective and efficient control of illegal land use in a highly dense environment, with high rise buildings in multiple leasehold ownerships.Design/methodology/approachMultiple cases were qualitatively analyzed, based on documentary analysis of the court proceedings.FindingsIn Cases 1 and 2, lease conditions for restriction to industrial purposes on aged industrial buildings were found to be obsolete and not economically viable, thus resulting in illegal conversion of the premises for commercial use. Cases 2 and 3 showed that ambiguity in user clauses in land leases could lead to illegal changes of use from industrial or residential to commercial activities. Most importantly, Cases 1 and 3 demonstrated that limited resources for lease enforcement are the fundamental cause of the problem. Cases 4 and 5 proved that property managers could take effective legal action against changes of use in buildings with multiple ownerships.Research limitations/implicationsThe results of this study are derived from five typical cases in Hong Kong, but they form a baseline upon which further research can build to test their significance in many other settings. Ultimately, a more robust strategy can be developed for ensuring an effective and efficient control of illegal land uses in the leasehold system for Hong Kong and for those countries with a similar tenure system.Practical implicationsA total economic and management strategy should be implemented by the government. The land management system should work in partnership with private property managers which are empowered under the Deed of Mutual Covenant (DMC) of multiple occupied buildings to take instant action against individual owners for breaches of lease conditions. The system should also be more flexible to expand the scope of new uses for aged industrial premises, allow affordable premium for lease modifications, as well as review and clarify any ambiguous user clauses in the related land ordinances.Social implicationsThe public should be educated that it is important to seek approvals and consents from the government prior to making any changes of land use. The government should also establish a housing policy to provide sufficient affordable housing for the lower income group so that illegal sub‐divisions on buildings for residential purposes can be eliminated.Originality/valueThe improvement measures identified can effectively enforce compliance with lease conditions, which in turn can reduce the enforcement transaction costs, ensure efficient allocation and use of land in the leasehold system, and maintain building safety.

EDUCATIONAL BUILDING PERFORMANCE EVALUATION PRACTICES AND PERCEPTIONS: A CASE OF FEDERAL UNIVERSITIES IN SOUTH EAST NIGERIA

This paper assesses the level of awareness, perception and practice of Building Performance Evaluation (BPE) in the management of educational buildings. Hitherto performance evaluation of buildings has not received significant attention in Nigerian Universities. Universities procure buildings that neither respond to the demands of changing needs, nor fit for purpose. This study relies on current literature to explore how the constructs of BPE can be utilized to improve the design and management of educational buildings in the Nigerian university system. Data were generated using a convenient sample of construction professionals holding key positions in the physical planning and works departments of four Federal Universities in South East Nigeria. Data analyses were conducted using Excel and statistica; Version 9.0. The findings suggest that there appears to be an apparent lack of a systematic mechanism for measuring the success or performance of completed and occupied buildings in the universities. The absence of a performance evaluation database in the institutions explains this situation. The study reveals inadequate funding and lack of skilled personnel to conduct the performance evaluation of buildings. Consequently, the interaction between users and buildings did not add value to learning and working experiences. The paper concludes that a significant number of buildings in the case organisations were not fit for purpose. Furthermore, building performance indicators/measures identified as specific design objectives seem not have been explicitly expressed in most of the buildings investigated. The study emphasizes the need for designers and facilities managers to acquire skills on critical aspects of building performance evaluation as a means of meeting the increasing demand for higher quality in education. The exploratory nature of this research clarifies the problems that need to be addressed in future studies and so raised a number of theoretical and conceptual issues that must be explored in the performance evaluation of educational buildings.

Understanding and developing quantitative risk criteria

AbstractThere are several factors that make the establishment of risk criteria a daunting task that few want to undertake. Nonetheless, for large global corporations, it is likely that one or more facilities have to meet governmental requirements. For US facilities, there is an incentive to having risk criteria in that it allows greater flexibility in complying with the updated API Recommended Practice 752 on siting of occupied permanent buildings. Having corporate risk criteria is imperative to ensure that facilities and operations that are not in “regulated jurisdictions” have a consistent framework to make risk‐related decisions. Risk criteria range from the use of the traditional risk matrix (consequence vs. likelihood) to the more quantitative risk criteria that include geographic risk (individual risk) and/or societal risk criteria. This article discusses the steps necessary to help companies develop robust defendable risk criteria that facilitate decision making. Potential pitfalls are also presented and discussed including: (a) the potential to develop criteria that are unachievable or too lax, (b) developing criteria that are inconsistent with other established programs in the company, and (c) reconciling the needs between unit level criteria and business or group level criteria. Typical risk‐tolerance criteria, and examples of issues and pitfalls that are commonly faced by companies developing such criteria, are also presented. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012

Experimental study of the thermal performance of a large institutional building with mixed-mode cooling and hybrid ventilation

The paper explores mixed-mode cooling strategies in buildings with hybrid ventilation and high levels of exposed thermal mass and presents data collected over an extensive period of time using a full-scale experimental set-up in an occupied institutional building with motorized façade openings integrated with an atrium. Night cooling strategies for thermal mass pre-cooling, with variable low temperature setpoint for control of airflow through operation of motorized grilles or a possible variable speed fan, are evaluated. Results for the thermal conditions in the highly-glazed atrium zone and the wind and buoyancy-driven airflow rates show that free cooling covers a significant portion of the building's cooling requirements while maintaining a comfortable indoor environment. The heat removal from concrete floor slabs is 2–5 times higher with the inlet air stream at an average temperature of 12 °C, compared to that with an air stream at 15 °C or 18 °C respectively. These findings provide insights for space conditioning using hybrid ventilation that can support the development of model-predictive control strategies.

A multivariable approach for estimation of vapor cloud explosion frequencies for independent congested spaces to be used in occupied building risk assessment

API Recommended Practice 752 is one of the most referenced practices for evaluating vapor cloud explosion (VCE) impacts to site occupied buildings. This reference introduces generic VCE frequencies for different types of process units that are based on VCE incidents database. Although these reported VCE frequencies are not capable of illustrating all parameters that affect explosion likelihood, they are widely used in risk analysis studies and software packages. This paper delineates the structure of a more realistic method for estimation of local VCE frequencies for independent congested spaces or units as a function of process, site, and meteorological variables. Compared to traditional methods for VCE frequency estimation, the new proposed approach is supported by an obviously more populated and precisely categorized database of leakage frequencies and features a multi-variable functionality of process/plant conditions. Contrary to previous procedures that aimed at finding the frequency of occurrence for a single VCE incident, this proposed methodology characterizes each congested space with a local VCE frequency. This frequency is an integration of the frequencies pertaining to VCE's that are likely to be initiated by each congested space. This new VCE frequency can also be used to determine the level of explosion hazard in each unit and in risk matrix analysis.

Quantifying the ‘human factor’ in office building energy efficiency: a mixed-method approach

There is an urgent need to understand the role that human competency, values and interests play in determining the energy efficiency of Australian commercial office buildings. Research focused on the interaction between building technologies and the people who operate them is therefore required, especially in the case of older buildings where accessible and cost-effective technologies and know-how that can abate greenhouse gas emissions have not, as yet, been widely adopted. We need to ground this analysis in ‘real-world’ operational data rather than speculative models. This article proposes a mixed-method approach for defining and quantifying the extent to which operations staff and other key decision makers influence the energy efficiency of occupied Australian commercial office buildings, and presents preliminary findings.

Secondhand smoke transfer and reductions by air sealing and ventilation in multiunit buildings: PFT and nicotine verification

Surveys suggest that transfer of secondhand smoke (SHS) between units in multiunit residential buildings is common, but measured data are rare. This study was undertaken to quantify bulk air transfer between units and document transfer of SHS species before and after treatments that sealed boundaries between units and provided a minimum amount of continuous exhaust ventilation of each unit. Six buildings in Minnesota were studied. Treatments were performed in clusters of up to eight units in each building, including zero to two units occupied by smokers. Bulk air transfer was quantified through passive perfluorocarbon tracer (PFT) gas tests. SHS transfer was evaluated using passive nicotine sampling. The median fraction of air entering a unit that came from other units tagged with PFTs ranged from 0.021 in a new condominium building to 0.353 in a 1930s duplex, with an overall median of 0.041. Treatments provided a median decrease of 29% in the fraction of transferred air and reduced PFT concentrations by about 40%, because of increased ventilation of both source and target apartments. Nicotine was transferred at only one-sixth the rate of PFTs. Involuntary exposure to SHS can be reduced but not eliminated by modifying existing, occupied multiunit buildings. Recent studies of secondhand smoke exposure in multiunit housing indicate transmission of SHS constituents from smokers' units to those occupied by nonsmokers. A straightforward solution for this problem is to eliminate air leakage transfer between these units. This study describes a 2-year investigation of air sealing and ventilation improvements in six multiunit buildings located in a heating-dominated climate region of the US. The results quantify the reduction in interunit transfer of air between smokers' and nonsmokers' units. While it is possible to reduce the transfer when done with care, it is extremely difficult to eliminate these flows unless the buildings are vacated and extensively rebuilt. Eliminating air leakage between smokers' and nonsmokers' units is not a practical means of solving SHS transmission in an existing building.

Life on the edge: Northern bobwhite ecology at the northern periphery of their range

AbstractOver the past 40 years, Northern bobwhite (Colinus virginianus) populations have declined range‐wide. The Mid‐Atlantic once held the highest densities in the country and now shows some of the worst declines. Although population parameters have been quantified throughout most of the bobwhite range, Mid‐Atlantic populations have been largely unstudied. To better quantify the dynamics of this declining system, we sought to not only gather annual data on home range, movement, and habitat selection, but also examine how some of these metrics might impact survival. We captured and radio‐tracked 154 bobwhites between May 2006 and April 2008 on a 125 km2 area of Cumberland County, New Jersey, USA. Seasonal daily movement ranged from 146 m to 158 m but several extreme movements were notable. Across seasons, grassland habitat was used in greater proportion to its availability, shrub‐scrub and agriculture habitats were used equally with their availability and forests and other habitats were used less than their availability. Differences in second‐order selection occurred between seasons with lower use of shrub‐scrub and forest habitats and higher use of other habitat in breeding seasons. Pooled breeding season survival was 0.343, nonbreeding season survival was 0.183, and annual survival was 0.063. Although mortality was dominated by avian predators, house cat mortalities were noteworthy. Cox proportional hazard analysis revealed that risk of breeding season mortality risk was increased by longer daily movement, lower grassland use, and higher forest and other use. During the nonbreeding season, risk of mortality increased with shorter daily movement and proximity to occupied buildings and barns. This information could inform management decisions in the greater Mid‐Atlantic as well as other areas of their range where they exist at very low abundances. © 2010 The Wildlife Society.

Dangerousness in firesetters: a survey of psychiatrists' views

Aims and MethodThe assessment of the future dangerousness of firesetters is problematical but psychiatrists may be requested to perform assessment of arsonists for the courts. We surveyed the views of psychiatrists and others (n=54) on how 11 candidate historical variables might contribute to future dangerousness.ResultsHierarchical cluster analysis indicated that variables fell into three groups related to level of perceived dangerousness. Apparent intention to endanger life and setting fire to an occupied building were the items thought by psychiatrists to most indicate highest future dangerousness. Having previously set fires that caused extensive damage, failure to extinguish previous fires or alert the authorities were perceived as indicating moderate future dangerousness.Clinical ImplicationsThe study adds to what is known about how psychiatrists formulate assessments of future dangerousness.