Search results for " Conditioning"
showing 10 items of 400 documents
Materiali e Tecniche Innovative per l'Edilizia Sostenibile
2021
Il cambiamento climatico e la necessità di ridurre il consumo energetico degli edifici sono argomenti chiave del dibattito politico, scientifico, economico e culturale. Un dibattito al quale si è voluto dare il proprio contributo sin dall’anno accademico 2010-2011 con la prima edizione del Master in Materiali e Tecniche Innovative per l’Edilizia Sostenibile (MeTIES) dell’Università degli Studi di Palermo insieme al Consorzio Universitario per l’Ateneo della Sicilia Occidentale e del Bacino del Mediterraneo (UNISOM), perseguendo il preciso obiettivo di formare una generazione di professionisti che sappiano padroneggiare le nuove tecnologie per ripensare il modo di “costruire”. Tutti gli stud…
Exergoeconomic analysis as a tool for supporting the design and operation of multiple chiller systems in air conditioning applications.
2019
Multiple-Chillers systems represent viable solutions for medium/large-scale air conditioning applications. In these systems, however, design and energy savings are highly affected by the configuration and operation strategies adopted. For instance, when considering multiple chillers of same size, “symmetric” or “sequential” load sharing strategies are two viable options. Conversely, when considering chillers of different sizes, a wide combination of chillers cooling capacities may be adopted. It is apparent that an integrated analysis of the design and operation of these systems should be carried out in order to achieve profitable energy saving. With this respect, Exergoeconomics, which res…
Development of “Design of Experiments” for modelling direct expansion air-conditioning systems under variable cooling loads and faulty operating cond…
2019
Air conditioning systems are widely adopted in the building sector and are generally responsible for high energy consumption. Part of this consumption is related to the poor maintenance adopted by plant owner over time, which causes energy performance degradation. Typical faults, such as fouling or improper refrigerant charge have been shown to heavily impact on energy consumption of these systems. In order to support cost-effective maintenance schedule, Fault Detection and Diagnosis Technique are under investigation in the world. However, in order to devise a diagnostic method a preliminary modelling of air conditioning system is due. To this aim, a test procedure which requires the least …
On the reliability of thermoeconomic diagnosis of fouled evaporators: assessing the influence of geometries, operating conditions and reference state
2015
Thermoeconomic diagnosis of refrigeration systems is a pioneeristic approach, which has been proven to achieve good performances (under favorable conditions) for the detection of specific faults such as condenser and evaporator fouling and compressor valve leakage. In this paper the sensitivity of performance in detecting fouled Direct Expansion (DX) coils is investigated; the examined parameters are the temperature and relative humidity of coil inlet air and the sensible/latent heat ratio of the coil (varied by considering different numbers of rows). As the thermoeconomic model requires splitting the specific exergy of cooling air into “mechanical”, “thermal” and “chemical” fractions, and …
Multi-Objective Building Envelope Optimization through a Life Cycle Assessment Approach
2019
This work describes a methodology for the identification of the optimal features for the envelope of a residential building. The optimization process allows minimizing operating energy consumption, investment costs and life cycle energy and environmental embodied impacts. A dynamic model for the estimation of building energy consumption during its use phase has been employed, while literature data were adopted for embodied energy and global warming potential impacts. The considered variables refer to the envelope of the building, i.e. external walls and roof insulation and external walls thermal mass. The model was obtained combining EnergyPlus building energy simulator and MOBO, a versatil…
Electrical hybrid heat pumps assisted by natural gas boilers: a review
2022
In this paper, a comprehensive review is performed on hybrid systems using electrical Heat Pumps for Heating, Ventilation & Air Conditioning systems and Domestic Hot Water production using case studies from 2016 to 2022. This work particularly focuses on studies that investigated systems with electrical Heat Pumps assisted by a gas boiler. Some studies that considered the exploitation of renewable energy sources, but not as a whole sub-stitute for fossil sources, have also been included. In particular, the analysis investigated the layouts of the systems by considering the type and the size of the components, the control methods applied (by distinguishing rule-based control methods and …
Thermo-hygrometric comfort in hospital rooms conditioned by means of a primary air system and ceiling radiant panels
2008
In this work the first results of experimental research are described, which began in the 2006 summer season and is still underway, on the performance of a primary air system integrated with radiant ceiling panels that runs in the hospital rooms in the maternity ward of the Maggiore Hospital of Bologna. The choice of this kind of environment is based the fact that there is more and more attention toward literature on comfort standards that must be guaranteed in the hospital environment, due to the presence of typically weak users, both from the clinical and psychological point of view. The performance of the air conditioning system is taken into account in relation to the conditions of comf…
LCA of a solar heating and cooling system equipped with a small water–ammonia absorption chiller
2012
The development of renewable energy technologies is a critical tool for reducing climate change and the reliance on fossil fuels. However, renewable energy technologies cannot be considered totally clean because they require energy consumption and have environmental impacts that cannot be neglected during their life cycle. In this paper, the life cycle assessment methodology was applied to assess resource use and other environmental burdens related to the entire life-cycle steps of a solar cooling plant. The investigated system works with an absorption chiller assisted by a solar plant. Two back-up configurations (hot back-up and cold back-up) were examined in two localities: Palermo (south…
PROTEIN SUPPLEMENT USE AMONG NETSURFERS VISITING HEALTH AND FITNESS COMMUNITY: FINDINGS FROM AN INTERNET-BASED SURVEY
2012
Introduction It is largely known that protein supplement (PS) use is a widespread and accepted practice by athletes and people who attend commercial gyms (Bianco et al., 2011). However, only few studies have been carried out in order to investigate supplement use and lifestyle in netsurfers of health and fitness community. For this reason the purpose of this preliminary study was to investigate the use of PS, age and lifestyle of people who visited a specific Italian sporting website: www.fitnessa360.com. Methods 273 subjects netsurfing in the www.fitnessa360.com completed the 6-item online-questionnaire about age, gender, daily cigarette consumption, protein supplement use, information sou…
Handgrip strength and 1RM bench press performance: a novel approach to evaluate upper body maximal strength
2012
In the last few years, handgrip strength has been widely recognized as a relevant indicator of physical function, nutritional status and quality of life in a clinical population. However, the scientific literature is still lacking of knowledge regarding the use of this indicator within a general healthy and physically active population. The possibility to use the handgrip strength as an indicative value of some specific physical qualities, such as the upper body maximal strength (expressed in terms of 1RM bench press), can be considered an unexplored field and its development might represent a relevant support for the strength and conditioning professionals. Therefore, we hypothesize that a…