Air Enthalpy as an IAQ Indicator in Hot and Humid Environment—Experimental Evaluation

Michał Piasecki,Krystyna Kostyrko,Katarzyna Nowak,Małgorzata Fedorczak-Cisak

doi:10.3390/en13061481

Michał Piasecki, Krystyna Kostyrko + Show 2 more

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https://doi.org/10.3390/en13061481

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Abstract

The authors studied the impact of indoor air humidity in the range of 60% to 90% on building user perception in the temperature range of 26 to 28 °C. The research thesis was put forward that the impact of humidity on indoor air quality dissatisfaction of building users in a warm and humid indoor environment is greater than that indicated in thermal comfort models. The presented experiment examined the indoor air quality perception of n = 28 subjects in the test chamber of a nearly zero energy building under ten environmental conditions, together with a thermal comfort assessment. The authors developed an experimental relation for predicting building users’ satisfaction based on the Weber–Fechner law, where the predicted percentage of dissatisfied users (PD) is determined by means of air enthalpy (h), PD = f(h). The obtained results confirmed the sated thesis. Additionally, the intersection points of the experimental function and isotherms resulting from the Fanger model are presented, where the thermal comfort assessment starts to indicate lower user dissatisfaction results than experimental values. The authors recommend the experimental equation for humid air enthalpies in the range of 50 to 90 kJ/kg. The indoor air quality assessment based on the enthalpy value is simple and can be used to determine the overall Indoor Environmental Quality index of a building (IEQindex).

Highlights

TheThe method of enthalpy prediction for afor given temperature, at which the results from the thermal method of enthalpy prediction a given temperature, at which the results from the thermal comfort model are starting be the lower thandissatisfaction the actual dissatisfaction
The authors confirmed that the impact of air humidity on user dissatisfaction related to indoor air quality has a greater impact on perception than a thermal sensation estimated based on the ISO 7730 model [19] and the ASHRAE Standard 55-2017 [26] for a hot and humid environment
Considering the significant increase in user dissatisfaction with indoor air quality for temperatures of 26 to 28 ◦ C with enthalpy higher than 51.3, 53.4 and 57.1 kJ/kg, in relation to the percentage of dissatisfied users (PD) value resulting from the thermal comfort model, the authors state that due to the global user satisfaction and indoor environmental quality index, the thermal assessment model based on the

Summary

Introduction

People are constantly exposed to the indoor environment of buildings, which is crucial for human thermoregulation and respiratory process; people’s reactions reflect the level of indoor air parameters. Considered the effect of temperature and humidity on people in a study for American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) on ventilation requirements. To date, both parameters are considered to be the most important elements impacting the satisfaction of building users. Since the beginning of the twentieth century, many environmental variables such as temperature, black ball temperature, relative humidity, air velocity, radiation and others have helped determine various indoor thermal comfort indicators [3]. Can show a dominant effect in certain situations, not necessarily

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