_Applied_  
_sciences_  
_Article_  
Experimental Comparison of Heating Emitters in Mediterranean Climate  
**[PERSON] 1,*, [PERSON] 1(c) and [PERSON] 2**  
1 DING-Department of Engineering, University of Sannio, 82100 Benevento, Italy; [EMAIL_ADDRESS]  
2 Department of Medicine and Health Sciences--[PERSON], University of Molise, 86100 Campobasso, Italy; [EMAIL_ADDRESS]  
*Correspondence: [EMAIL_ADDRESS]; Tel. : +39-(0)824-3055577  
**Abstract**: The need to increase the level of quality of indoor environments requires an extremely accurate definition of the microclimatic requisites to guarantee, in the spaces where people live and work, global and local conditions of comfort, considering, at the same time, the aspects related to energy savings and environmental sustainability. In this framework, the paper proposes a comparison of indoor parameters for three different types of heating emitters: fan-coils, baseboards heaters, and radiant floor systems. The comparison is based on seasonal monitoring performed in a test-room located in a Mediterranean climate; it can simulate an insulated room with office usage. The proposed indices demonstrate that the floor radiant system is characterized by lower horizontal and vertical differences in air temperature distribution that can guarantee more comfortable conditions and lower heat losses. The operative temperature is often higher than the neutral point; thus, management with a lower set-point temperature should be experimented with in further studies. More generally, the introduced method could help designers to choose the proper system and management strategy with the dual purpose to select a comfortable but energy savings-oriented operating temperature. thermal comfort; emitters; experimental measures; temperature distribution  
**1. Thermal Comfort: Indoor Plant Emitters and Control Strategies**  
According to the definition by ASHRAE [1, 2], thermal comfort is the condition of mind that expresses satisfaction with the thermal environment. It has a wide connotation, also including physiological and psychological aspects in addition to ambient characteristics [3, 4]. The overall thermal sensation and the degree of discomfort of people exposed to moderate thermal environments can be determined according to international standard EN ISO 7730 [5]. This standard allows the analytical determination and interpretation of thermal comfort conditions through the calculation of the predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD), as well as the analysis of local thermal discomfort phenomena (vertical air temperature differences, warm and cool floors, drafts, radiant temperature asymmetries). The PMV index, based on an analysis of the heat balance equation for the human body, takes into account the influence of thermal comfort factors (air temperature, air velocity, mean radiant temperature, humidity, clothing, and activity) by means of a value on a 7-point scale (0 is neutral, +1 is slightly warm, and \(-1\) is slightly cool). The PPD is correlated to the PMV value by means of a mathematical equation that reveals a small percentage of dissatisfied (5%) under thermal neutrality conditions (i.e., PMV = 0). According to the criteria of [5], three categories can be identified for classifying the thermal environment. These are shown in Table 1, where DR is the draught rate; \(\mathrm{T}_{\mathrm{f}}\) indicates the value of an acceptable floor temperature; \(\mathrm{\Delta T}_{\mathrm{P,EWc}}\) is the radiant asymmetry for a warm ceiling; \(\mathrm{\Delta T}_{\mathrm{P,FCc}}\) is the radiant asymmetry for a cool ceiling; \(\mathrm{\Delta T}_{\mathrm{P,FWc}}\) is the radiant asymmetry for a warm wall; \(\mathrm{\Delta T}_{\mathrm{P,CW}}\) is the radiant asymmetry for a cold wall; and finally in the last column there is the vertical difference between the value of air temperature measured at 1.1 m (T\({}_{a,1.1}\)) and at 0.1 m (T\({}_{a,0.1}\)).