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Overview of the Most Significant Standards on Thermal Comfort
Published in Ivana Špelić, Alka Mihelić-Bogdanić, Anica Hursa Šajatović, Standard Methods for Thermal Comfort Assessment of Clothing, 2019
Ivana Špelić, Alka Mihelić-Bogdanić, Anica Hursa Šajatović
Thermal comfort is defined by ASHRAE 55-2017 and the ASHRAE Handbook of Fundamentals as that condition of mind that expresses satisfaction with the thermal environment (ANSI/ASHRAE Standard 55-2017; ASHRAE Handbook of Fundamentals, 2017). ASHRAE 55 and ISO 7730 are the only standards that define local thermal comfort in an indoor environment (ANSI/ASHRAE Standard 55-2017; ISO 7730:2005). Thermoregulatory control mechanisms are unconscious and conscious, and humans consciously deduce conclusions on thermal comfort or discomfort based on direct stimulus from the skin and core of the body. In general, thermal comfort occurs when body temperatures are held within narrow ranges and when skin moisture is low or when the situation doesn’t require substantial physiological efforts of the organism for environmental adaptation. As a consequence of the adaptation, the human body is capable of initiating a number of conscious behavioural actions to reduce discomfort. Some of the possible behavioural actions for reducing discomfort are altering clothing variety, altering intensity and type of activity, changing posture or location, opening or closing a window, etc. Surprisingly, despite regional climate conditions, living conditions and cultures that differ widely throughout the world, the temperature that people choose for comfort, such as clothing, activity, humidity and air movement has been found to be very similar.
Human Thermoregulation System and Comfort
Published in Guowen Song, Faming Wang, Firefighters’ Clothing and Equipment, 2018
There are standards established to describe the thermal sensation and thermal comfort, including widely used ones like ASHRAE standard 55, ISO standard 7730, and CEN 15251. These standards present methods for assessing and predicting general thermal sensation and discomfort. In ASHRAE 55-2010, thermal comfort is defined as “the condition of mind that expresses satisfaction with the thermal environment.” Thermal comfort is the result of a comprehensive cognitive process of integrating physical, physiological, and psychological factors.
Evolving Industrial Hygiene Issues
Published in Martin B., S.Z., of Industrial Hygiene, 2018
ASHRAE Standard 55–1992, entitled Thermal Conditions for Human Occupancy, offers recommendations for acceptable temperature ranges to maintain occupant comfort in administrative and commercial facilities. The Standard takes into consideration seasonal variability when establishing acceptable ambient temperature ranges. Temperature ranges were established and corrected for clothing expected to be worn during each given season. Acceptable thermal comfort ranges have been generated for winter months and summer months. During summer months, ASHRAE 55–1992 recommends that indoor temperature ranges be maintained in the 73° to 79°F range, while the Standard recommends that temperature ranges in winter months be maintained between 68° and 75°F. ASHRAE Standard 55 also employs the use of psychrometrics to assist in the development of acceptability criteria. These temperature ranges were established with the intention of appeasing the comfort of 90% of a facility’s occupants.
Development of an optimization model for decision-making in building retrofit projects using RETROSIM
Published in Advances in Building Energy Research, 2023
Ehsan Asadi, Behrang Chenari, Adélio Rodrigues Gaspar, Manuel Gameiro da Silva
The parameter used to analyse thermal comfort is the predicted mean vote (PMV), based on Fanger’s model (Fanger, 1970). PMV is an indicator of what, on average, a large group of people would think of a thermal environment, and is used to analyse thermal comfort in standards such as ISO 7730 (ISO–ISO, 7730:2005–Ergonomics of the thermal environment–Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria) and ASHRAE 55 (ASHRAE Standard 55, 2010). It varies from −3 (too cold) to +3 (too warm), and a PMV value of 0 is expected to provide the lowest predicted percentage of dissatisfied people (PPD) among a group of people. In this article, an absolute value of 0.7 for PMV, the upper limit of category C, the less exigent comfort category in ISO 7730, is considered as the borderline of the comfort zone. Hence, to maximizethermal comfort, the total percentage of cumulative time with discomfort (|PMV| > 0.7) over the whole period during the occupancy, TPMVD(X), should be minimized. The total percentage of discomfort hours is calculated by TRNSYS. After processing this function in MATLAB, the Optimizer Engine uses the result to estimate TPMVD.
Review of practices for human thermal comfort in buildings: present and future perspectives
Published in International Journal of Ambient Energy, 2022
Sunil Kumar Sansaniwal, Jyotirmay Mathur, Sanjay Mathur
ASHRAE 55 is an exclusively designed thermal comfort standard widely used for the assessment of indoor thermal environment of different dwelling forms and types. It defines the acceptable range of conditions to majority of occupants (> 80%) exposed to the same environmental conditions. Whereas the specific dissatisfaction limit depends on the sources of local discomfort (ASHRAE 55 2013). Thus, the individual differences in preference may lead to individual dissatisfaction in the space meeting the standard criteria. However, the standard has limited scope and does not cover the effect of extreme and non-thermal environment on occupant’s health (Olesen and Brager 2004). Thermal comfort is the state of mind that expresses satisfaction with thermal environment and depends on the personal and ambient parameters. The ASHRAE 55-2004 specifies the estimated values of clothing insulation and metabolic rate as presented in Tables 3 and 4, respectively.
Review of studies on thermal comfort in Indian residential buildings
Published in Science and Technology for the Built Environment, 2020
Sunil Kumar Sansaniwal, Jyotirmay Mathur, Vishal Garg, Rajat Gupta
This standard was first published in 1966 and is primarily used in the United States, but it has become a well-known standard that is widely used for designing, commissioning, and testing of indoor environments. It defines thermal comfort as “the state of mind that that expresses satisfaction within the thermal environment.” ASHRAE 55 specifies a combination of personal and environmental factors to produce the acceptable conditions of indoor thermal environment suitable to the majority of occupants (>80%) exposed to identical environmental conditions within a space (ASHRAE 2017). The dissatisfaction limit based on differences in thermal preference of individuals is also specified in the standard. However, it has not covered the effect of the nonthermal environment on human health (Olesen and Brager 2004). Based on research advances and practical experience, ASHRAE 55 gets updated every 3 to 7 years, and the present notable versions of the standard are from 2004, 2010, and 2017.