PSI - Issue 29

Carla Balocco et al. / Procedia Structural Integrity 29 (2020) 25–33 Balocco, Vicario and De Vita / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 6. Mean hourly value of T, RH an x during closing and opening hours of the museum for the entire period in (a) PT01 and (b) PT04

The influenceof indoor thermal loadswas identified bycalculation ofmeanhourly valueof the thermo-hygrometric parameters referring to three user profiles: closingdays, openingdays from8:00 to14:00 and openingdaysfrom8:00 to 17:00. E.g., graphs for T, RH andx in PT01andPT03 are shown in Fig. 6. It canbe observed that during the closing days, thevalues of T, RH andx remain stable with minimal variations, while during the closingdays there is a rise in T and a decrease in RH during the openinghours. The switchingon the ligh ting system is the main cause of theT rise in PT01. This rise is a lso in PT03 a lthough lower. Ana lyzing the x value variations during the entire monitored period for both indoor and outdoor environment, it can be noted that theamount of internal vapor andconsequently the la tent heat loads are not very appreciable because are only due to the lowvisitors presence. Therefore the efficacy of VRF system for the control of the microclimatic conditions stability is guaranteed. As a matter of fact, the VRF solution is the best formuseums and exhibitions inside massive historic buildings, characterized by large volumes, without appreciable and impulsive latent loads. Only in the farther zones from the HVAC units and luminaires (i.e. PT04, PT05) and where the highest concentration of visitors was checked. It canbenoteda rise in T andRH with a x value increase. Fromdata analysis it canbe observed a non-homogeneous distributionof temperaturevalues with a vertical gradient of about 1°C between thePT05 located on the floor, and thePT04 located on the ledge, andwith a horizontal gradient of about 1°Cbetweenpoints PT03 and PT04 both located on the ledge, PT03 located closer to the indoor a ir units.