Satisfaction and self-estimated performance in relation to indoor environmental parameters and building features

The paper examines how satisfaction with indoor environmental parameters and building features affects satisfaction and self-estimated job performance. The analyses used subjective responses from around 50,000 occupants collected mainly in US office buildings using a web-based survey administered by the Center for the Built Environment (CBE) over the period of ten years. Overall satisfaction with the workspace significantly improved self-estimated job performance; increased satisfaction with temperature was estimated to provide the greatest improvement in self-estimated job performance, followed by increase in satisfaction with noise and air quality. The improvement of building features such as amount of space, visual privacy and noise level offered the highest chance to improve satisfaction with workspace. The study implies that it should be carefully considered how investments to upgrade indoor environmental quality and building design are used, and that they should consider whether comfort or working morale are expected to be improved.&nbsp

Impulsivity and self-harm in adolescence: a systematic review

Research supports an association between impulsivity and self-harm, yet inconsistencies in methodology across studies have complicated understanding of this relationship. This systematic review examines the association between impulsivity and self-harm in community-based adolescents aged 11-25 years and aims to integrate findings according to differing concepts and methods. Electronic searches of EMBASE, MEDLINE, PsychINFO, CINAHL, PubMed and The Cochrane Library, and manual searches of reference lists of relevant reviews, identified 4,496 articles published up to July 2015, of which 28 met inclusion criteria. Twenty-four of the studies reported an association between broadly specified impulsivity and self-harm. However, findings varied according to the conception and measurement of impulsivity and the precision with which self-harm behaviours were specified. Specifically, lifetime non-suicidal self-injury was most consistently associated with mood-based impulsivity related traits. However, cognitive facets of impulsivity (relating to difficulties maintaining focus or acting without forethought) differentiated current self-harm from past self-harm. These facets also distinguished those with thoughts of self-harm (ideation) from those who acted on thoughts (enaction). The findings suggested that mood-based impulsivity is related to the initiation of self-harm, while cognitive facets of impulsivity are associated with the maintenance of self-harm. In addition, behavioural impulsivity is most relevant to self-harm under conditions of negative affect. Collectively, the findings indicate that distinct impulsivity facets confer unique risks across the life-course of self-harm. From a clinical perspective, the review suggests that interventions focusing on reducing rash reactivity to emotions or improving self-regulation and decision-making may offer most benefit in supporting those who self-harm

Quantifying the Comprehensive Greenhouse Gas Co-Benefits of Green Buildings

This report quantifies, for the first time, the greenhouse gas (GHG) emissions co-­‐benefits associated with water, waste and transportation usage in certified green commercial office buildings in California. The study compares the measured values of water, waste and transportation usage self-­‐reported by a set of office buildings certified under the Leadership in Energy and Environmental Design rating system for Existing Building Operations and Maintenance (LEED-­‐EBOM) to both baseline values of conventional California office buildings and predicted values based upon state standards for green buildings and GHG impact prediction methods. The green buildings in the LEED-­‐EBOM dataset produced 50% less GHGs due to water consumption than baseline buildings, 48% less due to solid waste management, and 5% less due to transportation. If applied to the entire California office building stock, performance typical of the certified green buildings would save 0.703 MMTCO2e/yr from transportation, 0.084 MMTCO2e/yr from water, and 0.044 MMTCO2e/yr from waste, for a total potential savings of about 0.831 MMTCO2e/yr relative to conventional construction. In addition, buildings earning additional credits for specified performance thresholds for water and waste in the LEED-­‐EBOM code attained performance levels even higher than required by the code provisions, suggesting that such code provisions in other contexts may help incentivize larger GHG emissions reductions than anticipated

Data Collection Methods for Assessing Adaptive Comfort in Mixed-Mode Buildings and Personal Comfort Systems

The Adaptive Comfort Standard in ASRHAE Standard 55 currently is applicable only to naturally ventilated buildings, and no guidance is given on its relevance to buildings that are mixed-mode (combining operable windows with mechanical cooling), or have other forms of personal comfort systems, such as workstation heaters, fans, or ventilators. For these types of buildings or systems, the extent to which people will find the conventional PMV-based or adaptive-based comfort zones acceptable has a lot to do with how the building is designed and how it is operated throughout the year. And this is simply not yet known. There is a need for more field studies in these types of buildings to assess the specific design and operating characteristics that might influence adaptive comfort.  But to date there are no standardized methods for conducting such studies. The objective of this project was to identify a set of data collection protocols that would eventually allow us to investigate and potentially expand the adaptive comfort standards to account for mixed-mode and personal comfort system design strategies. To arrive at a proposal, we polled professionals for their own views on what data is needed, and also reviewed the literature comparing field methods used over the past decade that have expanded upon traditional thermal comfort field studies.  We used two frameworks to organize the data.  One was a “methods matrix”, describing the ways in which data can be collected, organized by background vs. real-time information, and objective building characteristics and environmental measurements vs. different kinds of surveys.  The second framework was a list of six high-level topics that represent unresolved issues that should be addressed by future data collection.  These issues include the need for improved methods to describe the building, document available controls, account for perceived control and thermal expectations, account for utilized control, determine the influence of outdoor conditions, and (re)define “comfortable”.  This second framework is used for a lengthy discussing of the literature to to understand how far research has come in addressing these issues.  This is later mapped onto the methods matrix in our proposal for new field study protocols

Data Collection Methods for Assessing Adaptive Comfort in Mixed-Mode Buildings and Personal Comfort Systems

The Adaptive Comfort Standard in ASRHAE Standard 55 currently is applicable only to naturally ventilated buildings, and no guidance is given on its relevance to buildings that are mixed-mode (combining operable windows with mechanical cooling), or have other forms of personal comfort systems, such as workstation heaters, fans, or ventilators. For these types of buildings or systems, the extent to which people will find the conventional PMV-based or adaptive-based comfort zones acceptable has a lot to do with how the building is designed and how it is operated throughout the year. And this is simply not yet known. There is a need for more field studies in these types of buildings to assess the specific design and operating characteristics that might influence adaptive comfort.  But to date there are no standardized methods for conducting such studies. The objective of this project was to identify a set of data collection protocols that would eventually allow us to investigate and potentially expand the adaptive comfort standards to account for mixed-mode and personal comfort system design strategies. To arrive at a proposal, we polled professionals for their own views on what data is needed, and also reviewed the literature comparing field methods used over the past decade that have expanded upon traditional thermal comfort field studies.  We used two frameworks to organize the data.  One was a “methods matrix”, describing the ways in which data can be collected, organized by background vs. real-time information, and objective building characteristics and environmental measurements vs. different kinds of surveys.  The second framework was a list of six high-level topics that represent unresolved issues that should be addressed by future data collection.  These issues include the need for improved methods to describe the building, document available controls, account for perceived control and thermal expectations, account for utilized control, determine the influence of outdoor conditions, and (re)define “comfortable”.  This second framework is used for a lengthy discussing of the literature to to understand how far research has come in addressing these issues.  This is later mapped onto the methods matrix in our proposal for new field study protocols

Advanced Design and Commissioning Tools for Energy-Efficient Building Technologies

This multi-year project generated significant new and improved software design tools and commissioning guidelines for underfloor air distribution (UFAD) systems, new performance guidelines for radiant slab cooled buildings, and an updated advanced Berkeley thermal comfort model. This final report presents detailed results in four major task areas as summarized below.Recommended commissioning guidelines were developed for the following three key elements affecting UFAD system performance: (1) procedures for measuring, adjusting, and optimizing room air stratification; (2) a new test protocol for determining air leakage from underfloor plenums; and (3) strategies and methods for controlling and managing thermal decay (temperature gain) in underfloor plenums. Emphasis is placed on commissioning procedures that are practical and as simple as possible for use by commissioning agents, and promote energy efficient operation while maintaining thermal comfort. The guidelines were developed through a combination of field and laboratory experiments, fundamental energy simulations, computational fluid dynamics (CFD) modeling, and simplified design tool studies.A number of improvements were made to EnergyPlus/UFAD, a version of the publicly available whole-building energy simulation program, EnergyPlus (developed under a previous PIER contract), which greatly enhanced its capabilities for modeling the more complex heat transfer processes found in UFAD systems. The improved version of EnergyPlus was in turn used as a basis for developing a more comprehensive simplified design tool for determining design cooling loads for UFAD systems, the first of its kind.Radiant slab cooling systems were found to demonstrate strong energy saving performance and improved occupant satisfaction in dry western U.S. climates based on a combination of occupant satisfaction surveys, two case studies, and whole-building energy simulations.The usability of the Berkeley thermal comfort model was improved by developing a user tutorial and demonstrated by conducting a case study of a building with a radiant floor slab

Visualizing the results of thermal comfort field studies: putting publicly accessible data in the hands of practitioners 

Large sets of thermal comfort field data have been analysed in detail to inform generalized thermal comfort standards, but there is specific information that might be relevant to particular projects that is not easily accessed by practitioners. We developed interactive tools that allow users to explore the data and look at the subsets that are most interesting to them because of location, culture, building type, etc. The first tool displays curves of dissatisfaction percentages for ranges of thermal sensation, PMV, and indoor temperature based on the comfort metrics of acceptability, comfort, and sensation. Using this tool, we show that a thermal sensation range of -1.3 to 1 provides 80% satisfaction based on acceptability and comfort in both naturally ventilated and air conditioned buildings. The second tool provides a new way of analysing and representing data in these datasets that calculates satisfaction percentage directly, and visualizes the results clearly. We demonstrate how the interactivity allows users to answer project-specific questions. While our visualization method is helpful for displaying the data, it does not provide a mathematically defined comfort zone. We discuss future avenues of development of these tools

Effect of a heated and cooled office chair on thermal comfort

A heated/cooled chair was evaluated for its effect on thermal sensation and comfort. Thirty college students participated in 150 1.75-h tests. Two heated/cooled chairs were placed in an environmental chamber resembling an office environment. The chamber temperatures were set at 16°C, 18°C, 25°C, and 29°C (60.8°F, 64.4°F, 77°F, 84.2°F). During the tests, subjects had full control of the chair surface temperature through a knob located on the desk. An additional 64 tests with 16 subjects were conducted at the same 4 temperatures but with regular mesh or cushion chairs in order to provide reference results for comparison. Subjective responses about thermal sensation, comfort, and temperature satisfaction were obtained at 20-min intervals and eight times before, during, and after a break period. The chair's energy consumption was monitored continuously. The results show that the heated/cooled chair strongly influences the subjects thermal sensation and comfort, providing thermal comfort under all tested conditions, both warm and cool. The average power draw is 27 W at 16°C (60.8°F), and 45.5 W at 29°C (84.2°F) ambient conditions. Copyright © 2013 Crown copyright