Vincenzo Franzitta

The recent post-pandemic period has economically affected many business sectors. One of these is the hotel industry. As a result of this economic crisis, it is necessary to act on the economic costs of running energy-intensive buildings such as a hotel. The thermal and electrical energy consumption of an accommodation facility weighs heavily on the economic balance. Governments around the globe have moved to help those activities in need. To improve the sustainability of the hospitality sector from an environmental and economic point of view, the introduction of energy retrofit solutions is mandatory. Following European sustainability laws, the impact and efficiency of the building were calculated using smart readiness indicators. The purpose of this paper is to present a case study of a 5-star hotel located in southern Italy characterized by high energy consumption. Precisely these consumptions are due to air conditioning, lighting, hot water, catering, and all other utilities. The entire building and the systems serving it were characterized by means of software that studies consumption with dynamic models, Trnsys. The same software made it possible to model the case study by replacing the existing air conditioning system with one supplied by renewable energies. Two energy retrofit hypotheses were chosen to obtain the best economic and environmental results. First, the choice was to install solar cooling powered by flat solar panels, and the second choice was solar cooling powered by evacuated tube collectors. This paper reports the technical and economic characteristics of both proposed solutions, quantifying the energy and economic savings to identify the best solution.

In Italy, a large part of the buildings classified as historical–artistic heritage is in a state of degradation and requires urgent interventions. Among the needs, a reduction in the high energy consumption and an improvement of the indoor comfort are mandatory. The case study of the “Ex Institute of Zoology of Palermo” shows how it is possible to achieve a reduction in energy consumption and preserve the building’s historicity through the estimation of energy loads and the subsequent processing. To quantify the energy savings of the structure, it was necessary to follow a few steps, namely an inspection of the building and an evaluation of its consumption. To elaborate a correct energy analysis, the thermal conductance was calculated by considering measurements over a period of 60 days and proceeding with the calculation of the transmittance. The resulting data are imported in the energy model developed with the TERMUS BIM software. In the case study, a potential energy saving equal to 35% of the current energy consumption can be avoided by replacing the lamps with LED ones, installing photovoltaic panels, replacing the heat pumps with a centralized system and the current fixtures with double thermal break fixtures. These interventions are implemented in compliance with the architectural peculiarities.