scholarly journals Thermal comfort in the low energy building - validation and modification of the Fanger model

2021 ◽  
Vol 246 ◽  
pp. 15003
Author(s):  
Natalia Krawczyk
Keyword(s):  
Thermal Comfort ◽  
Indoor Air ◽  
Thermal Sensation ◽  
Carbon Dioxide Concentration ◽  
Low Energy ◽  
Air Velocity ◽  
University Of Technology ◽  
Calculation Results ◽  
Thermal Comfort Model ◽  
The Impact

Nowadays, we spend most of our time inside buildings. Thus, ensuring adequate thermal comfort is an important issue. The paper discusses the issue of thermal comfort assessment in the intelligent low energy building “Energis” of Kielce University of Technology (Poland). The tests conducted in a selected lecture theater focused on collecting anonymous questionnaires containing thermal sensation and air quality votes of the respondents as well as performing measurements of indoor air parameters (air and globe temperatures, relative humidity, air velocity and CO2 concentration). Based on the obtained data a comparison has been done between the actual sensation votes of the volunteers and the calculation results performed with the Fanger thermal comfort model. Two indices have been considered in the paper: PMV (Predicted Mean Vote) and PPD (Predicted Percentage Dissatisfied). A modification of the model has also been proposed, which considers the impact of the carbon dioxide concentration on thermal comfort.

scholarly journals An indoor environment evaluation by gender and age using an advanced personalized ventilation system

2017 ◽  
Vol 38 (5) ◽  
pp. 505-521 ◽  
Author(s):  
Ferenc Kalmár
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Side Effect ◽  
Thermal Sensation ◽  
Ventilation System ◽  
The Other ◽  
Air Velocity ◽  
Personalized Ventilation

In a closed space, appropriate thermal comfort and proper indoor air quality are extremely important in order to obtain the optimal work performance and to avoid health problems of the occupants. Using advanced personalized ventilation systems, different comfort needs can be locally satisfied even in case of warm environments. Thermal sensation and the subjective evaluation of indoor air quality of young and elderly people, men and women respectively, were studied in warm environment using advanced personalized ventilation system combined with total volume ventilation system. Using an advanced personalized ventilation system, 20 m3 h−1 air flow was alternately introduced by three air terminal devices built-in the desk and placed on a horizontal plane at the head level of the sitting subject. Thermal sensation was significantly cooler in case of young women in comparison with the other groups. Odor intensity was evaluated to be significantly lower in case of elderly women in comparison with the other groups. Evaluation of air freshness is in correlation with the general thermal sensation. Variation of the direction of the air velocity vector has a cooling side-effect, which, in warm environments, might be useful in order to improve the thermal comfort sensation. Practical application: From the basic factors that influence the thermal comfort sensation, air velocity is the one and only parameter that must be treated as a vector. The air flow velocity has an important effect on the convective heat quantity released by the human body, but the changes in the air velocity direction have a cooling side-effect. This cooling side-effect should be exploited properly in warm environments by advanced personalized ventilation systems to improve the thermal comfort sensation of the occupants without supplementary energy use.

scholarly journals A Review of Thermal Comfort Applied in Bus Cabin Environments

2020 ◽  
Vol 10 (23) ◽  
pp. 8648
Author(s):  
Matheus das Neves Almeida ◽  
Antonio Augusto de Paula Xavier ◽  
Ariel Orlei Michaloski
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Co2 Concentration ◽  
Indoor Environments ◽  
Air Velocity ◽  
Research Papers ◽  
Current State ◽  
Energy Economy ◽  
Standard Models ◽  
The Impact

As of 2020, it has been 50 years since the publication of Fanger’s predictive model of thermal comfort that was designed for indoor environments and attention worldwide is directed at the COVID-19 pandemic and discussions around recommendations for these indoor environments. In this context, many environments and their occupants will suffer consequences related to thermal comfort due to the necessary indoor air changes. In bus cabins, the impact might be even greater, seeing that they are responsible for the mass transportation of people. Thus, this paper intends to review the studies on thermal comfort that analyzed bus cabin environments. It adapts the PRISMA methodology and, as a result, it includes 22 research papers published in journals. Among those, 73% focused on approaching the occupants’ thermal sensation, followed by fuel/energy economy (18%), and driver productivity (9%). The current state-of-the-art indicates that air temperature and air velocity were the parameters most employed by the included studies, but eight papers analyzed all six parameters of the standard models of thermal comfort. The most employed model of thermal comfort was Fanger’s, but there has not been an investigation that assesses its consistency in predicting the occupants’ thermal sensation in the explored environment. Nevertheless, the analyzed studies recommended constant air change inside closed buses or keeping them open to minimize adverse effects on the occupants’ health, especially due to airborne diseases and CO2 concentration possibly being a suitable indicator to identify the need for air change.

scholarly journals Acceptable air velocities using demand-controlled ventilation for individual cooling

2020 ◽  
Vol 172 ◽  
pp. 09002
Author(s):  
Kari Thunshelle ◽  
Henrik S. Nordby ◽  
Håkon Rikoll Solberg ◽  
Sverre Holøs ◽  
Peter G. Schild
Keyword(s):  
Relative Humidity ◽  
Thermal Comfort ◽  
Laboratory Study ◽  
Energy Demand ◽  
Thermal Sensation ◽  
Low Energy ◽  
Air Velocity ◽  
Controlled Ventilation ◽  
Summer Climate ◽  
Demand Controlled Ventilation

One of the main challenges in highly insulated buildings is the increasing share of energy demand for cooling. New solutions for low energy cooling are needed. Individual cooling by demand-controlled ventilation and use of ceiling mounted nozzles for cooling by higher air velocities could be an alternative. A laboratory study was designed to investigate thermal comfort and thermal sensation for elevated indoor room temperatures relevant to Norwegian summer climate; 24℃, 26℃ and 28℃ with a relative humidity set point of 40 %. Air flow was set to give air velocities of 0.25 m/s, 0.50 m/s and 0.75 m/s. 21 test persons were exposed to different air velocities in a cross-over study. Questionnaires on thermal comfort and thermal sensation were answered repeatedly. Jets from ceiling mounted supply air nozzles was shown to improve thermal comfort at 24 °C, 26 °C and 28 °C. In general, most test persons preferred low air velocity (0.25 m/s) at 24 °C, while high (0.5 m/s) or extra high (0.75 m/s) air velocities were preferred at 26 °C. At 28 °C, extra high or even higher air velocities were preferred.

Design Range of Indoor Relative Humidity in Radiant Cooling Environment

2011 ◽  
Vol 243-249 ◽  
pp. 4905-4908
Author(s):  
Xue Min Sui ◽  
Xu Zhang ◽  
Guang Hui Han
Keyword(s):  
Relative Humidity ◽  
Thermal Comfort ◽  
Mean Radiant Temperature ◽  
Design Standards ◽  
Human Thermal Comfort ◽  
Radiant Cooling ◽  
Climate Parameter ◽  
Radiant Temperature ◽  
Thermal Comfort Model ◽  
The Impact

Relative humidity is an important micro-climate parameter in radiant cooling environment. Based on the human thermal comfort model, this paper studied the effect on PMV index of relative humidity, and studied the relationship of low mean radiant temperature and relative humidity, drew the appropriate design range of indoor relative humidity for radiant cooling systems.The results show that high relative humidity can compensate for the impact on thermal comfort of low mean radiant temperature, on the premise of achieving the same thermal comfort requirements. However, because of the limited compensation range of relative humidity, together with the constraints for it due to anti-condensation of radiant terminal devices, the design range of relative humidity should not be improved, and it can still use the traditional air-conditioning design standards.

scholarly journals An Interactive Task Conditioning System Featuring Personal Comfort Models and Non-Intrusive Sensing Techniques: A Field Study in Shanghai

Technologies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 90
Author(s):  
Siliang Lu ◽  
Erica Cochran Hameen
Keyword(s):  
Thermal Comfort ◽  
Field Study ◽  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
New Paradigm ◽  
Dynamic Task ◽  
Current Task ◽  
Open Plan

Heating, ventilation and air-conditioning (HVAC) systems play a key role in shaping office environments. However, open-plan office buildings nowadays are also faced with problems like unnecessary energy waste and an unsatisfactory shared indoor thermal environment. Therefore, it is significant to develop a new paradigm of an HVAC system framework so that everyone could work under their preferred thermal environment and the system can achieve higher energy efficiency such as task ambient conditioning system (TAC). However, current task conditioning systems are not responsive to personal thermal comfort dynamically. Hence, this research aims to develop a dynamic task conditioning system featuring personal thermal comfort models with machine learning and the wireless non-intrusive sensing system. In order to evaluate the proposed task conditioning system performance, a field study was conducted in a shared office space in Shanghai from July to August. As a result, personal thermal comfort models with indoor air temperature, relative humidity and cheek (side face) skin temperature have better performances than baseline models with indoor air temperature only. Moreover, compared to personal thermal satisfaction predictions, 90% of subjects have better performances in thermal sensation predictions. Therefore, personal thermal comfort models could be further implemented into the task conditioning control of TAC systems.

Inter-personal factors affecting building occupants’ thermal tolerance at cold outdoor condition during an autumn–winter period

2019 ◽  
Vol 29 (7) ◽  
pp. 987-1005 ◽  
Author(s):  
Shahla Ghaffari Jabbari ◽  
Aida Maleki ◽  
Mohammad Ali Kaynezhad ◽  
Bjarne W. Olesen
Keyword(s):  
Air Temperature ◽  
Indoor Air ◽  
Thermal Tolerance ◽  
Thermal Sensation ◽  
Psychological Adaptation ◽  
Balance Model ◽  
Winter Period ◽  
Personal Factors ◽  
Outdoor Temperature ◽  
The Impact

The study was conducted to investigate thermal adaptation and the impact of individual differences on developing thermal tolerance when the outdoor temperature falls below 10°C. The applicability of the predicted mean vote (PMV) model was investigated, too. The concept of occupant’s ‘Temperament’ was evaluated as a psychological-adaptation factor. Two main hypotheses were: (a) people with different temperaments would experience different thermal sensations and (b) the classic PMV- predicted percentage dissatisfied (PPD) model is capable of predicting the neutral sensation in heated buildings under cold outdoor temperatures. There was a direct relationship between individual temperament and clothing level as well as thermal sensation. The occupants who were assessed to have cold temperament tend to wear thicker clothes and were more sensitive to variations in indoor air temperature than others. Females with a cold temperament were more than twice as likely to be affected by indoor air temperature as those with a warm temperament. The PMV-PPD model was able to predict the mean neutral temperature in the heated buildings even when the outdoor temperature fell below 10°C. However, when occupants were able to control high indoor temperature, the percentage of true prediction of actual mean votes by the adaptive thermal heat balance model was more than that by the classic PMV model.

scholarly journals User Thermal Comfort in Historic Buildings: Evaluation of the Potential of Thermal Mass, Orientation, Evaporative Cooling and Ventilation

2020 ◽  
Vol 12 (22) ◽  
pp. 9672
Author(s):  
Mamdooh Alwetaishi ◽  
Ashraf Balabel ◽  
Ahmed Abdelhafiz ◽  
Usama Issa ◽  
Ibrahim Sharaky ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
High Altitude ◽  
Air Temperature ◽  
Thermal Performance ◽  
Indoor Air ◽  
Computer Modelling ◽  
Evaporative Cooling ◽  
Comfort Level ◽  
Thermal Mass ◽  
The Impact

The study investigated the level of thermal comfort in historical buildings located at a relatively high altitude in the Arabian Desert of Saudi Arabia. The study focused on the impact of the use of thermal mass and orientation on the level of thermal performance at Shubra and Boqri Palaces. Qualitative and quantitative analyses were used in this study, including a questionnaire interview with architecture experts living at the relatively high altitude of Taif city, to obtain data and information from local experts. The computer software TAS EDSL was used along with on-site equipment, such as thermal imaging cameras and data loggers, to observe the physical conditions of the building in terms of its thermal performance. The study revealed that the experts’ age and years of experience were important aspects while collecting data from them during the survey. The use of thermal mass had a slight impact on the indoor air temperature as well as the energy consumption, but it helped in providing thermal comfort. Use of ventilation can improve thermal comfort level. Evaporative cooling technique has a considerable impact on reducing indoor air temperature with 4 °C drop, improving the thermal comfort sensation level. The novelty of this work is that, it links the outcomes of qualitative results of experts with field monitoring as well as computer modelling. This can contribute as method to accurately collect data in similar case studies.

Indoor air quality and thermal comfort evaluation in a Spanish modern low-energy office with thermally activated building systems

2015 ◽  
Vol 21 (8) ◽  
pp. 1091-1099 ◽  
Author(s):  
Francisco Javier Rey Martínez ◽  
Manuel Andrés Chicote ◽  
Antonio Villanueva Peñalver ◽  
Ana Tejero Gónzalez ◽  
Eloy Velasco Gómez
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Low Energy ◽  
Thermally Activated ◽  
Comfort Evaluation ◽  
Building Systems

scholarly journals Possible Perception Bias in the Thermal Evaluation of Evaporation Cooling with a Misting Fan

2021 ◽  
Vol 3 (1) ◽  
pp. 183-205
Author(s):  
Craig Farnham ◽  
Jihui Yuan
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Sensation ◽  
Air Flow ◽  
Low Energy ◽  
Perception Bias ◽  
Mist Cooling ◽  
Hot Environments ◽  
Subject Effect ◽  
Evaporation Cooling

Mist evaporation cooling (MEC) is increasingly used as a low-energy means to improve thermal comfort in hot environments. However, the thermal sensation votes (TSV) often overshoot values of Predicted Mean Vote (PMV) models. Evaluations of MEC may be affected by an expectation that mist feels cool or the “good subject” effect. Here, subjects are exposed to a misting fan and an identical fan without mist and asked which fan feels cooler. Unknown to the subjects, the misting fan has almost no cooling effect (about 0.4 K reduction in air temperature) and a hidden heater increased the temperature of the misting fan air flow, making it up to 1.6 K warmer than the fan without mist. Supplemental experiments told the subjects about the heater. Surveys of over 300 subjects when varying this misted air temperature showed a bias above random chance that people vote that a misting fan airflow was cooler, even when it was the same temperature or slightly warmer than the non-misting fan. It is possible that the expectation of cooling or good subject effect influences evaluations of mist. This effect should be considered in thermal comfort evaluations of mist cooling and in the deployment of MEC systems.

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