Contents lists available at ScienceDirect Sustainable Cities and Society journal homepage: www.elsevier.com/locate/scs On the necessities to analyse the thermohygrometric perception in aged people. A review about indoor thermal comfort, health and energetic aspects and a perspective for future studies Ferdinando Salata a, ⁎ , Iacopo Golasi a , Walter Verrusio b , Emanuele de Lieto Vollaro c , Mauro Cacciafesta b , Andrea de Lieto Vollaro a a Department of Astronautical, Electrical and Energy Engineering (DIAEE) – Area Fisica Tecnica, Università degli Studi di Roma “Sapienza”, Via Eudossiana 18, 00184, Rome, Italy b Department of Cardiovascular, Respiratory, Nephrologic and Geriatric Sciences (SCreNAG), Università degli Studi di Roma “Sapienza”, Piazzale Aldo Moro 5, 00185, Rome, Italy c Department of Architecture – Università degli Studi “Roma TRE”, Largo Giovanni Battista Marzi, 10 – Roma, 00154, Rome, Italy ARTICLE INFO Keywords: Aged people Thermal perception Indoor comfort Public health Energy efficiency Social costs ABSTRACT This study wants to examine the current bibliography concerning the thermohygrometric perception in aged people living in industrialized countries and its socio-economic consequences. Nowadays the number of European people between 70 and 90 years old is increasing, thus causing an aging of the average population. A proper and modern planning of indoor environments in residential buildings requires the presence of a good thermohygrometric comfort together with a low energy consumption level. The most common comfort indexes are the PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) provided by Fanger’s studies. Aged people present different demands with respect to the planning values suggested by Fanger. In particular, old people tend to live alone with a lower basal metabolic rate than active subjects and they are usually affected by pathologies provoked by the age. Medical studies revealed that pathologies might even be determined by indoor environmental conditions. Hence in order to have actual indoor comfort conditions able to satisfy aged people (especially during winter) different thermohygrometric values are required. This is why a higher energy demand is required and an optimization process should be performed to reduce the costs. Such condition will affect the future welfare of different countries. 1. About the importance of studies dealing with the thermal perception of aged people The thermal comfort sensation is a psychological and physiological condition expressing the thermohygrometric perception of the human being about the environment (both indoor and outdoor) surrounding her/him (Del Ferraro, Iavicoli, Russo, & Molinaro, 2015; ISO, 2005; Parsons & Kenneth, 2018). The thermal comfort is a consequence of the thermoregulation that the human body performs with respect to the conditions characterizing the environment surrounding the subject (ASHRAE, 2013a). Part of the energy that the human body produces (M) is consumed by the muscles (W); the rest of the energy (M–W) is dissipated towards the environ- ment through the body skin (Q sk ) and the breathing apparatus (Q res ) or it can be stored (S), thus causing an increase in the body temperature. − = + + = + + + + + + M W Q Q S C R E C E S S ( ) ( ) sk res sk res res sk c (1) The heat the body dissipates towards the environment occurs through different ways of heat exchange: the sensible heat exchanged through the skin (C + R) due to conduction, convection and irradiation phenomena, the latent heat due to skin evaporation (E sk ), the sensible heat affected by the breathing (C res ), the latent heat due to evaporation phenomena during the breathing process (E res ). The rest of the heat is stored in the skin (S sk ) and the body (S c )(Goromosov, 1968; Ormandy & Ezratty, 2012). This type of energy balance, even though it might seem simple, is actually complex depending on objective data (en- vironmental conditions) and personal or subjective ones as the per- ception of a sensation (thermohygrometric comfort of a human being) (Golasi, Salata, de Lieto Vollaro, Coppi, & de Lieto Vollaro, 2016; Pisello, Castaldo, Piselli, Fabiani, & Cotana, 2016; Salata, Golasi, de Lieto Vollaro, & de Lieto Vollaro, 2016), not easy to quantify (Hensen, https://doi.org/10.1016/j.scs.2018.06.003 Received 4 February 2018; Received in revised form 8 May 2018; Accepted 5 June 2018 ⁎ Corresponding author. E-mail addresses: ferdinando.salata@uniroma1.it (F. Salata), iacopo.golasi@uniroma1.it (I. Golasi), walter.verrusio@uniroma1.it (W. Verrusio), emanuele.delietovollaro@uniroma3.it (E. de Lieto Vollaro), mauro.cacciafesta@uniroma1.it (M. Cacciafesta), andrea.delietovollaro@uniroma1.it (A. de Lieto Vollaro). Sustainable Cities and Society 41 (2018) 469–480 2210-6707/ © 2018 Elsevier Ltd. All rights reserved. T