Romanian Climate Research Articles

Banana Ripening Plant with a Low Global Warming Potential Refrigerant and Heat Recovery for the Romanian Climate

Banana Ripening Plant with a Low Global Warming Potential Refrigerant and Heat Recovery for the Romanian Climate

A new adaptive thermal comfort model for the Romanian climate

Adaptive thermal comfort refers to the ability that the occupants of a building have to accustom themselves to specific thermal conditions. The notion of human thermal comfort (HTC) is therefore introduced and defined by a simple mathematical equation. In the evaluation process of actual buildings and in the design of new ones, adaptive HTC equations translate into a substantial reduction in energy consumption and maintenance costs to the buildings. Specialised databases provide adaptive HTC equations that are regarded as standard over large geographical areas. However, in particular climate regions, new adaptive HTC equations have to be established. This paper aims to find an HTC equation specific to the Romanian climate (Köppen climate type D – temperate continental climate). In order to achieve that, a field survey was conducted between 2013 and 2014 in several naturally ventilated buildings (two university buildings from Bucharest, a passive office building and a residential house). The input data consist of questionnaire surveys as well as measurements of comfort parameters.

Studies regarding the new peach assortments in south-eastern Romania

Thousands of peach cultivars are grown in the world and the breeders annually obtain new ones. Peaches are appreciated fruit for their nourishing and therapeutically qualities. The peach is a species with good adaptation and high yields under Romanian climate and soil conditions. The Romanian breeders made efforts to create valuable native cultivars. The aims were to obtain new peach, pavie, nectarine and brugnone cultivars with high qualities of fruit, big and constant productivity of trees, different habits of trees, various ripening time, etc. In the last 25 years the following cultivars showed good pomological results: ‘Raluca’, ‘Filip’ and ‘Florin’ – peach; ‘Costin’ and ‘Marina’ – nectarine; ‘Anemona’ – brugnone, homologated in 2010; ‘Mimi’, ‘Minodora’ and ‘Iustin’ – the new introduced clingstone cultivars, patented in 2014.

Assessment of the Quota of Recuperative Cooling of the Compressed Gas at Turbocharged Reciprocating Internal Combustion Engines

Turbocharging is a method of reducing the specific investment and raising the electrical efficiency of Reciprocating Internal Combustion Engines (RICE). The paper starts with a qualitative analysis, useful in educational purposes, about the energy flows and on the performances indices of RICE used for power generation and cogeneration. The paper continues with a statistical analysis of the manufacturers’ data for a RICE with turbochargers, useful in management purposes. The main paper’ section contains a computational model of compression and cooling air or air-gas mixture process, intended for Romanian climate. Its results are useful for RICE cogeneration.

First adaptive thermal comfort equation for naturally ventilated buildings in Bucharest, Romania

ABSTRACTNational and international adaptive thermal comfort (ATC) standards gain now wider acceptance. These standards propose adaptive comfort equations derived from specific databases. New ATC equations are developed worldwide, under different latitudes and climates. A field survey has been performed in 2013–2014 in six naturally ventilated buildings located in Bucharest (Romania, Köppen type D - temperate continental climate). Comfort parameters were measured and comfort questionnaires were distributed. Using the theory of ASHRAE 55 Standard an ATC equation specific to Romanian climate has been proposed for the first time. Also, the 80% and 90% acceptability bands were determined in this situation. The new ATC equation has been compared with other ATC equations found in literature for similar climates. New thermal comfort investigations have been performed one year later after the first survey, new comfort investigations were performed. The ATC equation has been checked and good agreement has been found.

Thermal Comfort in a Romanian Passive House. Preliminary Results

Thermal comfort is a very important aspect of building design and evaluation. Global current requirement is to reduce energy consumption which results in a preoccupation for low energy buildings. The challenge is to realize comfortable low energy buildings. Romanian climate (Köppen climate type D - temperate continental climate) in known for its cold winters and hot summers. The aim of this paper is to realize a thermal comfort study in a low energy building, an office building Passive House located in Romania, in summer period. For this purpose a field survey has been done in the summer of 2013, comfort parameters were measured inside the building and comfort questionnaires were distributed to the occupants. This paper compares the experimental results with the subjective response and analyzes the distribution of the thermal sensation votes on the building floors. Also, for two days of measurements, an adaptive thermal comfort evaluation is made, using thermal comfort standard EN 15251. Measurements data for one day placed the building in Category I of comfort (high level of expectation) and for the other day in Category II of comfort (normal level of expectation). Possible explanations are discussed in relation with thermal regime of the buildings.

Reducing energy consumption in low energy buildings through implementation of a policy system used in automated heating systems

The objective of this article is to analyze the opportunity of the nearly zero energy building (nZEB) concept implementation in Romanian climate conditions. Similar with the values in European Union, the largest share of energy consumption in Romanian buildings is due to the interior space heating. Therefore, our study was concentrated on energy consumption and interior comfort level of the low-energy house, built in the campus of POLITEHNICA University of Bucharest. The study house was built in accordance with the Passive House Institute (PHI) standards and it's equipped with a monitoring and data acquisition system for research purposes. The implemented Smart Building Controller (SBC) has an execution mechanism driven by a complex set of “policies”, which activates the heating system. It was found that the implementation of the SBC assures an optimal interior comfort and the total energy consumption for heating didn’t exceed the value imposed by the PHI (15kWh/m2/year). The energy balance analysis indicates that the total energy consumption can be covert in a major percentage by the energy production system (photovoltaic panels), making the nZEB concept an achievable goal.

Warm season cooling requirements for passive buildings in Southeastern Europe (Romania)

The first Romanian passive office building has been constructed by the AMVIC Company in Bragadiru, 10 km south of Bucharest. The overheating rate and the cooling load are higher for a passive building than for a standard building. The internal heat sources and the maximum allowed indoor temperature do markedly affect the cooling load. A time-dependent model shows that cooling is necessary during April-September. The ground heat exchanger is an effective system for cooling-down the fresh air inlet temperature. Also, the Venetian blinds prove to be efficient in diminishing the building heat input. However, these two systems are not able to ensure a controlled thermal comfort during summer. This suggests that an active cooling system should be used when passive buildings are implemented in the Romanian climate. The standard configuration of the passive buildings ventilation system (which is usually designed for heating purposes), must be changed in case cooling becomes necessary during the warm season. The results are of interest for other countries in Southeastern Europe.

THE INVESTMENTS – THE PREMISE OF THE AGRICULTURAL DEVELOPMENT

Throughout the evolution of the society, the investments have always had a major role in meeting the material and spiritual needs of human beings. The evolution of the economic and financial achievements of the any country‘s economy has depended on the investments and efficiency level. The correlation between the investments and the modernization is fundamental for any economic activity, no matter its field. The promotion of the technical and economic progress is a vital condition for our country’s economy and one of the most important ways of increasing its competitiveness, thus demanding considerable investments. Therefore, the need of an investment processes justifies the preoccupations for the assessment of the investment projects. The existence of various projects, a basic demand in carrying out any investment project, involves the choosing the optimal solution as being the purpose of the evaluation process of the investment projects. [1] Taking into account the main aspects of the agrarian politics and especially the European ones from the last five decades, it can be stated that they have suffered repeated changes, being constantly renewed and adapted to the technological conditions and to the demand on the agrarian market. The European Union agricultural policy can be considered to be an undeniable success, due tot the fact that in only two decades it has succeeded in remarkably reducing the importation of agricultural and food products, thus becoming the second exporter of the global agricultural market. Because of the Romanian climate, the achievement of high-efficiency and modern agriculture depends on the water supply through irrigation systems and their combination with fertilizers and amendments. Should these factors be added to a complete mechanization of the agricultural works, an efficient management, the individual property of the land and a properly-dimensioned exploitation, Romania’s agriculture could assure the resources for a population three times more numerous than the present one.

04/02429 Performance assessment of global solarirradiation models under Romanian climate: Paulescu, M. and Schlett, Z. Renewable Energy, 2004, 29, (5), 767–777

04/02429 Performance assessment of global solarirradiation models under Romanian climate: Paulescu, M. and Schlett, Z. Renewable Energy, 2004, 29, (5), 767–777

Performance assessment of global solar irradiation models under Romanian climate

Six global solar irradiation models were tested against data measured at three stations from Romania in the year 2000. One of the tested models, called EIM, is an empirical global solar irradiation model fitted by us, which requires as input a single meteorological parameter associated with the mean daily cloud amount. The accuracy of the EIM is acceptable and comparable to that of parametric models, which need more than one meteorological datum as input. The main conclusion is that such simple empirical “local-models” are a useful alternative for the more complicated one. In addition, the details of obtaining EIM are presented as a driven-tool, which may serve as a guide to elaborate similar simple solar irradiation models in any other location as well.