parametric performance analysis of renewable energy sources hvac systems for buildings

Abstract The indoor climate control of buildings represents today the highest percentage of energy consumption in European Union. Hence the evaluation of the best performing HVAC system is a strategic target for both energy consumption and greenhouse gas emissions reduction. This paper presents a deep analysis of the performance of Renewable Energy Sources HVAC systems for buildings. The technologies considered are biomass boiler, aerothermal, geothermal and absorption heat pumps. The proposed method estimates all the parameters according to the theory of the "big is better". For each parameter a function has been defined to evaluate how much the performance of each technology depends from it. The analysis take in account also the environment in which each technology operates. The result is a set of dimensionless parameters, through which it is possible to extrapolate the assessments of performance. It can include both cost-effectiveness and feasibility of a given technology and the contribution to the achievement of European objectives to 2020

Trigeneration Plants in Italian Large Retail Sector: a Calculation Model for the TPF Projects with Evaluation of all the Incentivizing Mechanisms

The object of this research is an economic analysis of trigeneration systems (or Combined Cooling, Heat and Power - CCHP) through a calculation model developed for applications in the field of large retail sector. Particular attention has been given to the validation of Third-Party Financing (TPF) projects. The analysis is carried out in comparative form, considering all the existing variants of the Energy Performance Contract and the incentive mechanisms for trigeneration plants. The study is based on an econometric model of calculation for CCHP systems whose results are validated on a case study described in detail. The input data of the simulation come from an energy audit platform developed specifically for the analysis of typical HVAC systems of large retail sector. The study results consist of 50 scenarios of TPF projects. They highlight the economic advantage in the trigeneration plants management for both parties (ESCo and customer) and make it possible to determine the options of contract needed to verify the feasibility of TPF projects

Conceptual Study of a Thermal Storage Module for Solar Power Plants with Parabolic Trough Concentrators

The thermal storage technology (TSE) has a relevant strategic importance for the success of solar plants devoted to electric energy and heat production. The major benefits in the use of storage include higher efficiency and reduction in the mean levelled cost of the electric energy unit (LEC). Sensible heat storage systems within solid media have been identified, both technically and economically, as a very promising solution. The development of such a storage technology, adopting concrete, could reduce the specific cost to less than 20\u20ac per kWh of thermal capacity; additionally, such a solution is suitable for small-medium size plants with a power ranging from 1 MW to 5 MW, to be easily introduced in the Italian territory and with reduced operational and maintenance needs. In large size CSP systems, as the ARCHIMEDE plant built by ENEL with ENEA technology, a high temperature fluid storage (between 400 and 500\ub0C) is required. Such a temperature seems at present not adequate to allow for adopting concrete, whereas the production of concrete able to sustain 250-300\ub0C appears as a reachable objective. It is supposed to study a storage system characterised by a parallelepiped structure with appropriate section, selfbearing and supported on its major axis, as well as by a piping system directing the thermovector fluid within the cemented matrix

Quantitative Microbial Risk Assessment as support for bathing waters profiling

Profiling bathing waters supported by Quantitative Microbial Risk Assessment (QMRA) is key to the WHO's recommendations for the 2020/2021 revision of the European Bathing Water Directive. We developed an areaspecific QMRA model on four pathogens, using fecal indicator concentrations (E. coil, enterococci) for calculating pathogen loads. The predominance of illness was found to be attributable to Human Adenovirus, followed by Salmonella, Vibrio, and Norovirus. Overall, the cumulative illness risk showed a median of around 1 case/10000 exposures. The risk estimates were strongly influenced by the indicators that were used, suggesting the need for a more detailed investigation of the different sources of fecal contamination. Area-specific threshold values for fecal indicators were estimated on a risk-basis by modelling the cumulative risk against E. coll. and enterococci concentrations. To improve bathing waters assessment, we suggest considering source apportionment locally estimating of pathogen/indicator ratios, and calculating site-specific indicators thresholds based on risk assessment

Management of Microbiological Contamination of the Water Network of a Newly Built Hospital Pavilion

The good installation, as well as commissioning plan, of a water network is a crucial step in reducing the risk of waterborne diseases. The aim of this study was to monitor the microbiological quality of water from a newly built pavilion before it commenced operation. Overall, 91 water samples were tested for coliforms, Escherichia coli, enterococci, Pseudomonas aeruginosa and Legionella at three different times: T0 (without any water treatment), T1 (after treatment with hydrogen peroxide and silver ions at initial concentration of 20 mg/L and after flushing of water for 20 min/day for seven successive days) and T2 (15 days later). Coliforms were detected in 47.3% of samples at T0, 36.3% at T1 and 4.4% at T2. E. coli was isolated in 4.4% of the samples only at T1, while enterococci appeared in 12.1% of the samples at T1 and in 2.2% at T2. P. aeruginosa was isolated in 50.5% of the samples at T0, 29.7% at T1 and 1.1% at T2. Legionella pneumophila serogroup 8 was isolated in 80.2% of the samples at T0, 36.3% at T1 and 2.2% at T2. Our results confirmed the need for a water safety plan in new hospital pavilions to prevent the risk of waterborne diseases

Impact of lockdown on the microbiological status of the hospital water network during COVID-19 pandemic

The COVID-19 pandemic started in China in early December 2019, and quickly spread around the world. The epidemic gradually started in Italy at the end of February 2020, and by May 31, 2020, 232,664 cases and 33,340 deaths were confirmed. As a result of this pandemic, the Italian Ministerial Decree issued on March 11, 2020, enforced lockdown; therefore, many social, recreational, and cultural centers remained closed for months. In Apulia (southern Italy), all non-urgent hospital activities were suspended, and some wards were closed, with a consequent reduction in the use of the water network and the formation of stagnant water. This situation could enhance the risk of exposure of people to waterborne diseases, including legionellosis. The purpose of this study was to monitor the microbiological quality of the water network (coliforms, E. coli, Enterococci, P. aeruginosa, and Legionella) in three wards (A, B and C) of a large COVID-19 regional hospital, closed for three months due to the COVID-19 emergency. Our study revealed that all three wards' water network showed higher contamination by Legionella pneumophila sg 1 and sg 6 at T1 (after lockdown) compared to the period before the lockdown (T0). In particular, ward A at T1 showed a median value = 5600 CFU/L (range 0-91,000 CFU/L) vs T0, median value = 75 CFU/L (range 0-5000 CFU/L) (p-value = 0.014); ward B at T1 showed a median value = 200 CFU/L (range 0-4200 CFU/L) vs T0, median value = 0 CFU/L (range 0-300 CFU/L) (p-value = 0.016) and ward C at T1 showed a median value = 175 CFU/L (range 0-22,000 CFU/L) vs T0, median value = 0 CFU/L (range 0-340 CFU/L) (p-value < 0.001). In addition, a statistically significant difference was detected in ward B between the number of positive water samples at T0 vs T1 for L. pneumophila sg 1 and sg 6 (24% vs 80% p-value < 0.001) and for coliforms (0% vs 64% p-value < 0.001). Moreover, a median value of coliform load resulted 3 CFU/100 ml (range 0-14 CFU/100 ml) at T1, showing a statistically significant increase versus T0 (0 CFU/100 ml) (p-value < 0.001). Our results highlight the need to implement a water safety plan that includes staff training and a more rigorous environmental microbiological surveillance in all hospitals before occupying a closed ward for a longer than one week, according to national and international guidelines

The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance

The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5-11 December, to 17.5% (25/143 samples) in the week 12-18, to 65.9% (89/135 samples) in the week 19-25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased from one in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons. In conclusion, we designed an RT-qPCR assay capable to detect the Omicron variant, which can be successfully used for the purpose of wastewater-based epidemiology. We also described the history of the introduction and diffusion of the Omicron variant in the Italian population and territory, confirming the effectiveness of sewage monitoring as a powerful surveillance tool

The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance

The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5–11 December, to 17.5% (25/143 samples) in the week 12–18, to 65.9% (89/135 samples) in the week 19–25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased fromone in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons