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In this paper the results of a wide investigation on a geothermal-integrated air HVAC system are reported: in the first part, the energy performances of an Earth to Air Heat eXchanger (EAHX) operating in Pomezia (a locality of the area of Rome, Italy) are carried out through a comprehensive numerical two-dimensional model based on the finite element method and the system is forced under real time-changing weather conditions over 1 year. The model is able to reproduce the time- and space- dependent thermo-fluid-dynamic behavior of the EAHX system, the humid air flux and the surrounding soil, as well as to account for the mass of condensed water in the tubes. In the second part of the investigation, the EAHX is coupled to an air handling unit of a company building for office use and tested while operating both in cooling and heating mode. The hourly results, in terms of power savings and energy consumption were reported for representative days of all the months belonging to the cooling or the heating working seasons, monthly and seasonal assessment. The convenience in terms of seasonal energy savings is +40.8% in cooling mode and +44.1% in heating mode. Then, the economic impact in terms of payback time and net present value was investigated through a cost analysis to examine the return of the economic investment under two possible soil morphologies and different prices of electrical energy in Italy. The simple payback with the real price of energy in Italy (0.50 €/kWh) is 3.3 years for the tufa-soil and 5.8 years for soft rock-soil; the economic return in terms of net present value is around 500 k€ for both the morphologies (560 k€ for the tufa; 446 k€ for the soft rock), per effect of the energy saving and, consequently, for a reduced expense of electrical energy. Therefore, in all the considered cases the installation of EAHX systems in support of traditional systems would generate both energy and economic advantages. [ABSTRACT FROM AUTHOR]

Energy efficiency of cultural heritage is not only an engineer issue. Many professionals and Institutions have to be involved in the design process. Furthermore, the building survey plays a crucial role in providing opportunities to the designers to find the most compatible solution. This paper shows the “Galleria Borghese” case study, in Rome, which is one of the most important Italian museum. Recent literature defined the energy efficiency of listed buildings dedicated to museum as the most challenging environment. For this reason, this study explored the available rooms to guarantee Indoor Environmental Quality, architecture preservation and sustainability. The disruption caused by some plant breakdowns climate that have occurred in recent years provided stress to the visitors comfort and overall exhibited works unsuitable for their preservation. From an analysis of the current situation and the calculation of winter and summer thermal loads of the building and the ventilation air flow rates, the study shows some viable proposals having as objective: the reduction of the heat load of the building in summer, a better air exchange and overall a modernization of the plant expansion. A participatory process allowed to involve in the design architectural elements by converting them to a new role such as the chimney of fireplaces as part of the new HVAC system. [ABSTRACT FROM AUTHOR]

In the early Imperial age Roman unroofed theatres were endowed with velaria . Velaria were awnings made of sailcloth, in either canvas, linen or cotton, attached to spokes of rope that could be extended or retracted with ropes and pulleys over the cavea . Their main purpose was to provide shade for the spectators who watched the show in blistering sun and heat. The aim of this paper is to understand if velaria , beside their primary function, could affect the acoustics of the theatres. A specific study was carried out with the use of a commercial software for the prediction of room-acoustics characteristics of halls. Actually, numerical simulations were aided by acoustic measurements performed in two existing theatres, namely the “Teatro Grande” in Pompeii and the “Teatro Romano” in Benevento as they are in the present state. Both theatres are used rather regularly for public shows including music of various genres and drama. Like other ancient theatres not in a good state of conservation both theatres are deficient of natural reverberation because of the lack of structural elements important for this acoustic feature. To overcome inherent drawbacks electroacoustic means are used. However, there are instances where these remedial measures are not appropriate. The results of this study show that the use of suitable awnings can improve the reverberation in these venues. [ABSTRACT FROM AUTHOR]

• A glazing (AGS) with aerogel granules and opaque hollow silica is studied. • Thermal and lighting performance of the AGS are analysed in an experimental field. • The air temperatures with AGS are lower than the ones with a standard glazing. The excellent thermal insulation properties of aerogel glazing systems make them an interesting building solution, especially in cold climates. When aerogel glazing systems provide less solar heat gain factor, they could be useful in warm and hot regions (such as Tokyo, Rome and so on) because buildings in such areas are often designed to minimize cooling energy demands. If a sort of opaque powder is mixed with aerogel granules, able to stick to each granule and to cover the aerogel surface discontinuously, the mixture can thus reduce solar transmittance, contributing to daylight usage with less glare risks and cooling energy demand reduction, without shade or blinds, keeping as high thermal performance as aerogel. This innovation is examined in the present paper, by presenting the following solution: a double glazing unit with a mixture of silica granular aerogel and hollow silica powder in the gap (AGS), in order to reduce the solar factor. The solution is tested through in-field experimental campaigns and numerical analyses, making available a set of data not found in literature, where mixtures of aerogel and powder were never studied. The air temperatures in the test Room with AGS, especially the peak values, are lower than the ones in the reference one with installed a standard glazing system (SGS). The same behaviour is observed in several experimental campaigns in different seasons: in mid-season 1 the highest differences are of about 6–7 °C, whereas in summer they reach 12–16 °C. Significant differences in terms of illuminance are also observed: the calculated Useful Daylight Illuminance (UDI) shows AGS values 57% higher than SGS, highlighting the aerogel ability to diffuse light and to reduce glare. Experimental data were used for energy analyses of a reference building in Tokyo. AGS outperforms a low-e glazing in terms of heating energy demand: the reduction varies in the 22% (North) − 62% (South) range. The lighting energy demand is quite similar: electricity demand increases in the 3–6% range. Finally, the internal shade on the reference glazing has a significant impact on the estimated energy demand, both for cooling and heating. [ABSTRACT FROM AUTHOR]

• A 3D microclimatic model in ENVI-met is used to simulate a misted urban area. • The model predicts accurately the horizontal and vertical air temperature distribution. • Wind speed plays a major role both in terms of cooling capacity and influence area. • Water flow rate and height of injection can be tuned to regulate the cooling capacity. Among water-based mitigation strategies against urban overheating, dry mist systems are especially promising, given their local impact, cost-effectiveness and controllability. Intense cooling capacity has been reported under a variety of climates, however, there is a growing need to define specific design guidelines towards an informed and optimized use of the technology. Parametric analysis on validated models would assist in determining type and degree of correlation between key parameters, as well as magnitude and predictability of the cooling capacity. In this paper, for the first time, a 3D microclimatic model in ENVI-met is used to simulate a misting system installed in Rome, Italy, with high prediction accuracy for the air temperature (R2≃0.87, RMSE≃0.84 °C). The calibrated ENVI-met model is used then to perform parameterizations on the water mist system, focused on the role of three key design variables: i) water flow rate, ii) injection height and iii) local wind speed. Results show that the most significant thermal drops tend to occur close but out of the misted perimeter following the wind direction, with cooling effects further stretched for tens of meters. The cooling capacity increases with the total water flow rate (+0.2 °C per 10 l/h increment) and in presence of calm air (+35–40% per 0.8 m/s deceleration). Lower injections intensify the cooling a pedestrian height, which could be especially beneficial under windy conditions. Further research would target climate dependencies to extend the applicability of the above results and build up cohesive guidelines at the hands of urban planners and practitioners. [ABSTRACT FROM AUTHOR]