Field study on thermal comfort in naturally ventilated and air-conditioned university classrooms

Abstract

Maintaining a satisfactory thermal environment is of primary importance, especially when the goal is to maximize learning such as in schools or universities. This paper presents a field study conducted in Milan during summer 2017 in 16 classrooms of Politecnico di Milano, including both naturally ventilated (NV) and air-conditioned (AC) environments. This study asked 985 students to report their thermal perception and their responses were evaluated according to the measured thermal comfort parameters to assess the prediction as given by Fanger and adaptive models, according to ANSI/ASHRAE 55-2017 and EN 15251:2007 standards. Furthermore, an analysis regarding potential effects of gender in comfort perception was performed. The results confirmed the fitness of Fanger’s model for the prediction of occupants’ thermal sensations in AC classrooms with a reasonable accuracy. In NV classrooms, the Adaptive model was proven to be suitable for predicting students’ comfort zone according to ASHRAE 55 Standard, while the adaptive comfort temperatures recommended by EN 15251 were not acceptable for a large number of students. No significant differences in thermal comfort perception between genders have been observed, except for two NV classrooms in which females’ thermal sensation votes had resulted closer to neutrality in comparison to males, who expressed a warmer thermal sensation.

Keywords

Thermal comfort Field study Fanger model Adaptive model Natural ventilation Gender

Get full access to this article

View all access options for this article.

References

ANSI/ASHRAE Standard 55-2017. Thermal environmental conditions for human occupancy. Atlanta, GA: American Society of Heating, Refrigeration and Air Conditioning Engineers, Inc., 2017.

Parsons

KC.

Human thermal environments. The effects of hot, moderate, and cold environments on human health, comfort and performance. London: Taylor and Francis, 2003, pp.196–228.

de Dear

Akimoto

Arens

Brager

Candido

Cheong

KWD

Zhu

Progress in thermal comfort research over the last twenty years. Indoor Air 2013; 23: 442–461.

de Dear

Brager

Cooper

Developing an adaptive model of thermal comfort and preference. Final report ASHRAE RP-884. Atlanta, GA: American Society of Heating, Refrigerating and Air Conditioning Engineers, 1997.

ANSI/ASHRAE Standard 55-2004. Thermal environmental conditions for human occupancy. Atlanta, GA: American Society of Heating, Refrigeration and Air Conditioning Engineers, Inc., 2004.

Nicol

Humphreys

Derivation of the adaptive equations for thermal comfort in free-running buildings in European standard EN15251. Build Environ 2010; 45: 11–17.

BS EN 15251:2007. Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics. London: BSI, 2007.

Humphreys

Quantifying occupant comfort: are combined indices of the indoor environment practicable?

Build Res Inf 2005; 33: 317–325.

Zomorodian

Tahsildoost

Hafezi

Thermal comfort in educational buildings: a review article. Renew Sustain Energy Rev 2016; 59: 895–906.

10.

Rupp

Vásquez

Lamberts

A review of human thermal comfort in the built environment. Energy Build 2015; 105: 178–205.

11.

Yao

Liu

Occupants’ adaptive responses and perception of thermal environment in naturally conditioned university classrooms. Appl Energy 2010; 87: 1015–1022.

12.

Cândido

de Dear

Lamberts

Bittencourt

Air movement acceptability limits and thermal comfort in Brazil’s hot humid climate zone. Build Environ 2010; 45: 222–229.

13.

Buratti

Ricciardi

Adaptive analysis of thermal comfort in university classrooms: correlation between experimental data and mathematical models. Build Environ 2009; 44: 674–687.

14.

Memon

Chirarattananon

Vangtook

Thermal comfort assessment and application of radiant cooling: a case study. Build Environ 2008; 43: 1185–1196.

15.

Liuzzi

Nico

Stefanizzi

Evaluation of thermal comfort in university classrooms through objective approach and subjective preference analysis. Appl Ergon 2015; 48: 111–120.

16.

Fanger

PO.

Thermal comfort. Copenhagen: Danish Technical Press, 1970.

17.

Kim

de Dear

Cândido

Zhang

Arens

Gender differences in office occupant perception of indoor environmental quality (IEQ). Build Environ 2013; 70: 245–256.

18.

Zaki

Damiati

Rijal

Hagishima

and Abd Razak A. Adaptive thermal comfort in university classrooms in Malaysia and Japan. Build Environ 2017; 122: 294–306.

19.

Humphreys

Nicol

Environmental criteria for design. In: CIBSE Guide A: environmental design. London: The Chartered Institution of Building Services Engineers, 2006, p.12.

20.

ASHRAE Handbook . Fundamentals. Atlanta, GA: American Society of Heating, Refrigeration and Air Conditioning Engineers, 2009.

21.

UNI EN ISO 7726. Ergonomics of the thermal environment, instruments for measuring physical quantities. Rome: Ente Nazionale Italiano di Unificazione, 2002.

22.

Nicol

Humphreys

Roaf

Adaptive thermal comfort: principles and practice. London and New York: Routledge, 2012.

23.

UNI EN 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. Rome: Ente Nazionale Italiano di Unificazione, 2005.

24.

Nicol

Wilson

A critique of European Standard EN15251: strengths, weaknesses and lessons for future standards. Build Res Inf 2011; 39: 183–193.

25.

Von Grabe

Winter

The correlation between PMV and dissatisfaction on the basis of the ASHRAE and the McIntyre scale towards an improved concept of dissatisfaction. Indoor Built Environ 2008; 17: 103–121.