## 2 Case Setup
In fact, the use of CFD allows for the prediction of these parameters even during the design of the HVAC system, so it is possible to evaluate the best operative conditions of the fan coil together with the distribution of the furniture inside the domain. The UNI EN ISO 7730:2005 [21] standard presents methods for predicting the general thermal sensation and the degree of discomfort (thermal dissatis \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Season** &
\begin{tabular}{c} **Inlet Air Velocity** \\ **(m/s)** \\ \end{tabular} & **Solar Load** \\ \hline Case E & Heating & 1 & NO \\ Case F & Heating & 2 & NO \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of the studied configurations in winter–eating conditions. Figure 3: Final mesh. (**a**) View of the mesh from outside of the office; (**b**) view of the furniture. Figure 2: Velocity and temperature values in one point obtained for the five different grids. to moderate thermal environments. Then, it is possible to evaluate the levels of comfort in enclosed environments by calculating the local discomfort parameters,e and predicted mean vote (\(PMV\)) and associated predicted percentage dissatisfied (\(PPD\)) values ([PERSON], 1970) ([PERSON], 1970). The single evaluation of the \(PMV\) usually tends to over- or underestimate the real thermal comfort perception, as reported by [PERSON] (2014) ([PERSON], 2014), [PERSON] et al. (2014), and [PERSON] et al. (2015). As a global index, the \(PMV\) alone is not able to accurately recreate the real thermal perception since it does not account the possible effects of local discomfort felt by an occupant. Thus, we propose analysing local and global thermal comfort indices, and the effects of their combination for the evaluation of thermal comfort. According to the standard ([PERSON], 1970), Equations (6) and (7) allow for the evaluation of the dissatisfied percentage due to vertical air temperature gradients (\(PD_{v}\)) and floor temperature (\(PD_{f}\)), respectively. \[PD_{v}=\frac{100}{1+e^{(5.76-0.856\Delta T)}} \tag{6}\]  
where \(\Delta T\) is the temperature difference in the range of a sitting person between their head (1.1 m) and ankles (0.1 m). \[PD_{f}=100-94e^{(-1.387+0.118T_{f}-0.0025T_{f}^{2})} \tag{7}\]  
where \(T_{f}\) is the floor temperature. Equation (8) allows for the identification of the drought rate (\(DR\)) due to air flow. \[DR=(34-T_{a})(v_{a}-0.05)^{0.62}(0.37v_{a}T_{u}+3.14) \tag{8}\]  
where \(T_{a}\) is the air temperature, \(v_{a}\) is the air velocity, and \(T_{u}\) is the turbulence intensity. Equation (8) is only applicable when the air velocity is less than 0.5 m/s. CFD analysis allows for knowing the velocity values in each point of the domain. In this work, the velocity values were above the limit only in the zone right next to the fan-coil unit, so it was reasonable to use the \(DR\) equation in the rest of the room where the occupants were. The \(PMV\) considers the body as a whole; thus, it differs from the previous indices and is a global parameter that depends on several parameters (Equation (9)). Some are environmental parameters, such as air temperature \(T_{a}\), air velocity \(v_{a}\), the water vapour partial pressure \(p_{a}\), and mean radiant temperature \(T_{MR}\). Others are individual parameters, which are metabolic rate \(Met\) and clothing insulation \(I_{clo}\). \[PMV=PMV(T_{a},v_{a},p_{a},T_{MR},Met,I_{clo}) \tag{9}\]  
According to the standard ([PERSON], 1970) and related works, a \(Met\) rate of 1.2 and a \(I_{clo}\) of 0.5 ([PERSON], 1970) were assumed for people in a sitting position performing a sedentary activity during the summer season. For winter, a \(I_{clo}\) of 1 was considered instead ([PERSON], 1970). The \(PMV\) classifies the environment in a scale from \(-3\) to \(+3\), where 0 is a neutral condition in which occupants have the best thermal comfort perception, while \(-3\) and \(+3\) represent extreme sensations of cold and hot, respectively.