Nicola Cardinale

Heating-energy consumption in different plant operating conditions

Abstract A system of heating-plant and building was monitored in order to measure the heating-energy consumption necessary to maintain thermal comfort conditions during the occupation time of the building. Recorded data allowed the identification of a black-box model of the system, which relates the heating-energy consumption to the daily mean exterior temperature. Two different operating conditions of the heating-plant were examined, a continuous one and an intermittent one; the energy consumption in the heating period has been evaluated. The energy consumption in both conditions is comparable though heating time lapses are remarkably different. Continuous operation is best when the times of required thermal comfort are longer than in the monitored situation.

Thermo-Hygrometric Evaluations in the Recovery of Rocky Buildings of the “Sassi of Matera”(Italy):

The Sassi of Matera are a very interesting example of a rocky settlement. The limestone walls often present high moisture content which negatively influences the room microclimate. In the first part of this paper, rooms without evident problems of moisture were analyzed for the purpose of carrying out a statistical analysis, to be repeated in analogous situations and to identify the distribution of what we can define as background moisture of the rocky installation. The knowledge of moisture, however, greatly influences the evaluation of heat loss since thermal conductivity of a material increases with an increase in the percentage of water that is contained within it. Consequently, the second part of the paper deals with thermal conductivity and other thermal physical properties related to the moisture of the calcareous sandstone present in the installation of the “Sassi,” continuing the analysis initiated in a previous work.

Bio-Climatic Technologies in Mediterranean Countries

Under the point of view of Sustainable Development a number of lessons can be learnt by traditional approach to environmental modifications. In the building sector, most of the principles of ancient strategies have been again proposed during the last century so as to be in accordance with environmental as well as urban conditions. Nevertheless both the ancient procedure and the modern approach need to be compared with the environmental and morphological actual conditions of the site. If the “genius loci” of Norberg Shultz can never be known without a basic scientific learning of the place, both in terms of physical and social conditions, then the intercourse between construction and climate can never be neglected. While during the traditional architecture and the ancient building methods, the procedure was locally found, according to natural as well as elementary technologies and materials, however with the modern design process and practice, this care for the local environment, climate and typology had been completely unattended.

Economic-Environmental Performance of Micro-wind Turbine in Mediterranean Area

Through the study of wind resources for the site of the “Murgia Materana” Park, located in the Murgia plateau between Basilicata and Puglia, we deduced the potential of wind energy in this area of southern Italy, a typical Mediterranean area. The measurements, carried out over a period of 365 days, allowed to characterize and assess the windiness of the site from an energetic, economic, and environmental point of view for four different types of micro-wind turbines: two horizontal axis turbines with power of 6 and 20 kW and two vertical axis turbines of equal power. This technology, characterized by a low environmental impact, can be used to supply loads, even in areas subject to environmental constraints, with very low costs of installation and maintenance. The analysis on energy productivity, the equivalent hours of operation, the return on investment, and environmental benefits in terms of emissions of CO2, NOx, SOx, and TEP, compared to conventional sources (power plant), allowed to determine which of the turbines is the one that best suited to site studied. The last issue was to assess the cost per kWh produced and compare it with other energy sources. The value obtained was competitive equaling the cost of the kWh produced by a power plant or a third-generation nuclear power plant with significant environmental benefits such as zero emissions of CO2 and storage of nuclear waste.

A stochastic dynamic method for the evaluation of the heating power input of a real building-plant system

Abstract A Prediction Error Method to set up a black-box model of a whole building-plant system based on experimental data series is proposed. This model is used to evaluate the dynamic heating power of the generator as a function of the external air temperature. In spite of the model having been built from of a limited monitored period, it is suitable for simulating the thermal performance of the system over longer periods. This allows the best power rating of the heat generator to be found; an over-dimensioned generator operates with a low load factor and a low efficiency. The proposed method can be applied very well for the substitution of heat-generators in existing plants.