44 research outputs found
Application of time series models for heating degree day forecasting
No full textThis study aims at constructing short-term
forecast models by analyzing the patterns of the heating
degree day (HDD). In this context, two different time series
analyses, namely the decomposition and Box–Jenkins
methods, were conducted. The monthly HDD data in
France between 1974 and 2017 were used for analyses. The
multiplicative model and 79 SARIMA models were constructed by the decomposition and Box–Jenkins method,
respectively. The performance of the SARIMA models was
assessed by the adjusted R2
value, residual sum of squares,
the Akaike Information Criteria, the Schwarz Information
Criteria, and the analysis of the residuals. Moreover, the
mean absolute percentage error, mean absolute deviation, and mean squared deviation values were calculated
to evaluate the performance of both methods. The results
show that the decomposition method yields more acceptable forecasts than the Box–Jenkins method for supporting short-term forecasting of the HDD
Statistical significance of gender and age on thermal comfort: a case study in Turkey
No full textMaintaining thermal comfort in buildings is essential since it affects user's health and performance. Thermal comfort standards provide reference values for indoor environmental parameters; however, they cannot incorporate gender and age in their theories, in which the predicted mean vote (PMV) is used. The aim of this study was to investigate the effects of gender and age on thermal sensation, preference and acceptability as well as verifying the applicability of the PMV model. In order to obtain PMV and actual mean vote values, in situ measurements and surveys were carried out simultaneously in a religious building in Turkey. Statistical analyses, including the Shapiro-Wilk, Levene, Kruskal-Wallis and Games-Howell tests, were conducted to understand the statistical significance between females and males as well as four age groups. The results show that the PMV model is applicable for both females and males; however, it cannot be verified for all age groups except for the age group of 46-65 years. The relationship between thermal sensation and age group is stronger compared with that between thermal sensation and gender. Moreover, the effect of age group on thermal preference and thermal acceptability is statistically significant, whereas that of gender is not significant
BEMServer And Occupant Behaviour: A New Approach Towards Addressing The Energy Gap in Buildings
No full textThe actual energy consumption of buildings in Europe often exceeds design energy
predictions by a significant margin. This gap between actual energy performance and design
energy performance can arise from construction errors, commissioning errors and/or the way
buildings are actually used. Moreover, occupant behaviour is now widely recognized as a
major contributing factor to this gap. HIT2GAP is a Horizon 2020 EU-funded project that
seeks to reduce the gap between predicted and actual energy consumption of buildings. To do
this, HIT2GAP develops an energy management platform (BEMServer) which could
eliminate this gap in existing buildings, by providing a data platform, energy predictions and
benchmarks as well as modules that address the concerns of facility and energy managers.
This study presents the BEMServer and the semantic driven behaviour module that is
developed within the HIT2GAP project. The architecture of the BEMServer as well as the
behaviour module’s functionalities, the outputs and the use cases are provided
Assessing user thermal sensation in the Aegean region against standards
No full textThermal comfort is an important criterion in design, operation and commissioning of commercial and residential buildings. Today, building systems are operated according to the predefined set points, which are determined according to the standards that have predefined comfort ranges for all climatic zones. However, users' thermal sensation, preference and acceptability might vary for different climatic conditions, and, thus, operating buildings and predicting the comfort performance of buildings by measuring its adherence to the standards might not represent the perceived thermal sensation and satisfaction of users. This study aims at assessing the perceived thermal sensation of users in the Aegean region against the thermal comfort standards ASHRAE 55 and ISO 7730. Indoor environmental conditions were monitored and a survey study was carried out to obtain predicted mean vote (PMV) and actual mean vote (AMV), respectively. The results show that the PMV model underestimated the percentage of dissatisfied users in the environment and was not able to detect the thermal unacceptability in both seasons. Moreover, it was found that users prefer cooler environments both in the heating and cooling seasons. Therefore, lower temperatures compared to the standards should be maintained in order to ensure thermal comfort conditions. (C) 2016 Elsevier Ltd. All rights reserved
Dataset of occupant density, indoor environmental conditions and thermal comfort survey in open plan offices during the COVID-19 pandemic
No full text<p><span>The objective measurements were carried out during weekdays between September 27<sup>th</sup>, 2021 and October 22<sup>th</sup>, 2021 during the COVID-19 pandemic. Thermal conditions were monitored between 8:30AM until 17:30PM with an interval of 5 minutes. The HVAC systems were not operating during the case study period and the building was conditioned via natural ventilation according to the recommendations of the UCTEA Chamber of Mechanical Engineers </span><span>(UCTEA Chamber of Mechanical Engineers, 2020)</span><span>. The objective measurements included indoor air temperature, relative humidity, globe temperature and air velocity, which were measured by probes connected to off-the-shelf anemometers. Thermal comfort variables were measured at a height of 0.60 m in accordance with the requirements of the ASHRAE 55-2013 and ISO 7730 Standards for an occupant at sitting position. Equation (1) presents the formulation of the operative temperature in ASHRAE55 Standard. Here, A is weighting factor determined based on the air velocity. In this study, A was determined as 0.5 according to the ASHRAE55 Standard since all air velocity measures were lower than 0.2 m/s.Moreover, Ta represents<span> </span>indoor air temperature, To represents operative temperature, Tr <span> </span>represents mean radiant temperature.</span></p>
<p><span>To = A × Ta + (1 − A) × Tr<span> </span>Eq. (1)</span></p>
<p><span>A questionnaire was designed to obtain information related to occupants’ responses to their thermal environment. Within this context, occupants were asked to express their thermal sensations according to the ASHRAE thermal sensation scale. In addition, the questionnaire included questions regarding occupants’ thermal preference and satisfaction by using a three- and a two-point scale, respectively. The occupants provided their responses at the end of the day, reflecting their overall experience during the day. A total of 1400 responses were collected and all of them were included in the analysis.</span></p>
<p><span>UCTEA Chamber of Mechanical Engineers. (2020, July 6). <em>Recommendations for offices during<span> </span>pandemic</em>. Https://Www.Mmo.Org.Tr/.</span></p>
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Data Acquisition Technologies for Assessing Thermal Comfort in the Built Environment
No full textNowadays, many buildings are equipped with sensors that acquire large amounts of data, which can be useful to monitor, to understand and to identify thermal comfort conditions in buildings. The studies on thermal comfort of building interior spaces are not only numerical analysis based on program outcomes, but also experimental studies to confirm the results of the analysis. However, the most important factor in achieving the correct result in experimental analysis is to plan the data, to select the technology and to determine the test procedure. This study aims at providing an important source for experimental researchers working on thermal comfort by identifying data acquisition technologies that are utilized for capturing thermal comfort related data. Within this context, the study presents existing instruments utilized for monitoring thermal comfort conditions and provides a guideline with respect to technical properties, deployment strategies and time intervals. The findings of this study will be beneficial to practitioners and researchers for selecting and utilizing the most appropriate data acquisition technology for assessing thermal comfort in indoor environments.HIT2GAP "Highly Innovative building control Tools Tackling the energy performance gap" project of the European Union's Horizon 2020 research and innovation programme [680708]This work has received funding from HIT2GAP "Highly Innovative building control Tools Tackling the energy performance gap" project of the European Union's Horizon 2020 research and innovation programme under grant agreement number No. 680708
Understanding the Relationship between Indoor Environmental Parameters and Thermal Sensation of users Via Statistical Analysis
No full textCreative Construction Conference, CCC 2017 -- 19 June 2017 through 22 June 2017 -- 137308Thermal comfort in indoor environments has a significant effect on user's health and wellbeing. Its effect becomes crucial especially in classrooms since it affects students' performance with respect to attention, comprehension and learning levels. This study assesses thermal comfort conditions via field measurements and subjective surveys. A university building, which is located in the Mediterranean climatic region of Turkey, was selected as a test site and the study was performed for ten days in the heating season. Indoor air temperature, mean radiant temperature, relative humidity and air velocity were monitored to obtain the Predicted Mean Vote (PMV) whereas a total of 235 subjective surveys were conducted to obtain the Actual Mean Vote (AMV). The comparison of PMV and AMV as well as the robustness of the relationship between PMV and AMV were analyzed via the t-test and Pearson correlation coefficient, respectively. In addition, the effect of users' relative humidity and air velocity perceptions on the thermal sensation and thermal acceptability were evaluated via cross tabulation and chi-square independence tests. The results show that the difference between the PMV and AMV values is statistically significant and the relationship between PMV and AMV has a very strong positive correlation. The results of the chi-square tests indicated that the thermal sensation and thermal acceptability are depended on users' relative humidity and air velocity perceptions. © 2017 The Authors
Monitoring and Post-Occupancy Evaluation of a Regenerative Indoor Environment
No full textThis chapter presents a critical systematization of: a) Procedures for conducting Post-Occupancy Evaluation (POE) campaigns (e.g., longitudinal, point-intime, transversal);b) Protocols and tools (including the identification of sensors,instruments, etc.) to measure building performance data (related to the Key Performance Indicators (KPIs) presented in Chapter 2); c)Protocols and tools (including questionnaires, forms, etc.) for collecting quantitative (e.g., surveys, etc.) and qualitative occupant data (e.g., focus groups, structured interviews, etc.).Considering that several procedures, protocols and tools are currently available, the systematization has been structured through the following methodological steps: 1) review of scientific papers from peer-reviewed journals, online documentation, extracts from books and conference proceedings, among others; 2)collection of information from existing POE providers (e.g., websites, direct contact, etc.); and, 3) analysis of criteria and requirements embedded in current standards and green building certification systems. For each of the above aspects, the information is presented discussed, and synthetized in tables. A comprehensive reference list at the end of this chapter offers a wide overview of the various literature sources from which all the information presented in this booklet has been gathered
