1,722,008 research outputs found
Impact of using different models in practice - a case study with the simplified methods of ISO 13790 standard and detailed modelling programs
No full textThe updated ISO 13790 Standard is part of the new set of CEN Standards that supports the European Energy Performance of Buildings Directive (EPBD) requirement for a general framework for calculation of the energy consumption of buildings. The Standard sets out procedures for space heating and cooling energy calculations, allowing the use of three different methods: a simplified monthly quasi-steady state method, a simple-hourly method and detailed simulation. This paper examines the implications of allowing different methods to be used for assessing the energy usage. The research method used was to undertake a comparison of the various methods applied to a common building specification, with parametric analyses of variations in this specification. The paper discusses differences in results for heating and cooling requirements between the simplified methods and when a detailed simulation program (ESP-r) is used with constrained (according to the Standard) inputs and with a number of unconstrained inputs. The case where two different detailed simulation programs (ESP-r and EnergyPlus) are used in practice for the same building is also included and conclusions are drawn regarding the practical use of different detailed modelling programs against the simplified methods, as well as against each other
Comparison Of Quasi-Steady State And Dynamic Simulation Approaches For The Calculation Of Building Energy Needs: Thermal Losses
Get PDFOne of the aims of the European Directive 2010/31/EU (formerly 2002/91/EC) is to reduce the energy consumption of buildings introducing an energy labeling protocol which is expected to capture the attention and reorient the market, sustaining the diffusion of more efficient solutions. In order to evaluate the building energy performance, either analytical approaches or enhanced simulation tools are allowed. The coherence of the methods is important in order to avoid misleading results which can affect the evaluation by the market and eventually compromise the Directive effectiveness. The European Standard EN ISO 13790:2008 suggests to use the dynamic simulation in improving and tuning the quasi-steady state method proposed, and in particular to refine the correlation used to calculate the utilization factors (i.e., the dynamic parameters which reduce the thermal gains for heating need calculation and the thermal losses for cooling). Many efforts in calibrating the EN ISO 13790:2008 led to some changes on the correlations proposed in order to adapt the method to the climatic conditions, especially for the cooling season, and the building stock’s characteristics in different countries, but large discrepancies have been found. Differently from the previous works, the authors analyze the discrepancy sources focusing firstly on thermal losses, instead of considering directly the final result in term of energy needs. In this paper, the deviations between the thermal losses are evaluated, by means of an extensive use of simulation, analyzing a set of a 960 configurations obtained by the factorial combination of different values for the building shape, envelope insulation and composition, window type and size, ventilation rate and climatic conditions. Six different setpoint conditions were considered for the simulations. The analysis allowed the authors to identify the relevance of the deviations and to suggest ways to improve the correspondence between simulation and quasi-steady state methods in tuning processes
Building Energy Benchmarking for Retrofit: An Application of Normative Building Modeling
Get PDFNormative building modeling, addressed in ISO 13790 (Thermal performance of buildings-Calculations of energy use for space heating), has been adopted in major European countries in various applications, including building energy certificate and energy forecast for building stock in regional, national, or international scale. This wide adoption in Europe stems from the capability of normative modeling to deliver objective, yet indicative building energy performance results. This study presents a simplified approach for building energy model calibration by coupling normative energy calculation method and the Latin Hypercube Sampling (LHS) method. The light weight normative energy calculation method requires a limited number of building inputs which could be collected through a quick walk-through onsite audit. And its minimum computation requirements allow the calibration process to search the entire feasible space more thoroughly and in a timely manner. Coupling normative energy calculation and LHS provides users a simple and yet effective tool for building audit and energy model calibration in support of retrofit decision making. A case study on an existing mix-use university building is presented to demonstrate the performance of the proposed approach. Limitations and suggestions to future work are also discussed
Comparison of the simplified methods of the ISO 13790 standard and detailed modelling programs in a regulatory context
No full textThe CEN Standards that support the European Energy Performance of Buildings Directive requirement for calculation of the energy consumption of buildings allow various methods to be used for the same calculation. The impact of using the different methods within the updated ISO 13790 Standard for space heating and cooling energy calculations was examined with a parametric analysis of a common building specification. The impact was assessed by considering the energy band which would be assigned for the building based on the calculation results. The Standard describes three different methods that can be used for the calculations: a monthly quasi-steady state method, a simplified hourly method and detailed simulation. For most cases studied, differences in the building rating given by the various methods were a maximum of one band. More significant differences were noticed in some cases. Parameter values in the monthly method were determined which would lead to improved matching
Solar Load Ratio and ISO 13790 methodologies: Indirect gains from sunspaces
Get PDFThis paper reviews and analyzes the compatibility of the simplified empirical method based on the dimensionless parameter of Solar Load Ratio (SLR) and the monthly procedure of the standard ISO 13790 for indirect gains, specifically for unconditioned zones adjacent to a conditioned zone, but separated from it by a partition wall (sunspaces).
The main contribution of the work presented here is the new formulation to account SLR correlations in ISO 13790, obtained for sunspaces, but generalizable for other solar systems with known SLR functions.
Simulation models are used to perform a sensitivity analysis of internal gains and heat transfer through solar collector surfaces, both issues that distinguishes ISO 13790 from Load Ratio methods. The analysis
shows that internal gains can be added to the heat source term or subtracted to heat transfer term without influencing the utilization factor dependence with the gain-to-loss ratio. On the other hand, the SLR assumption that solar collector surfaces are neutral elements and, therefore, not added to the heat transfer term, results in large inconsistencies between SLR and ISO 13790 methods.
The detailed monthly methodology of ISO 13790 fairly reproduces results obtained by simulation. However, predictions from the simplified monthly methodology of ISO 13790 fail in mid season months and coldest months
ISO 13790 한국형 유효계수 결정 방법론에 관한 연구
No full textUtilisation factors used in ISO 13790 are determined by time constant and gain/loss ratios and should be redefined for climate condition to improve the accuracy of the heating/cooling loads in each region or country. The purpose of this study is to suggest reference time constants and dimensionless reference numerical parameters which are applicable for buildings in Korean context. Using Energy plus detailed simulation models were made representing high weight/high insulated rooms surrounded by external environment and a light weight (curtain wall type) room adjacent to internal environment. Equivalent models were made with an ISO 13790-based calculation tool in which numerous combinations of reference time constants and dimensionless reference numerical parameters can be tested. After examining the agreement between results from Energy plus simulation and those of the ISO 13790-based tool, a set of reference time constants and dimensionless reference numerical parameters are suggested which reduce the error rates significantly. This paper presents the methodology of new utilisation factors calculation and outcomes of the examination
Testing of technical systems in plant protection according to standards EN 13790 I and EN 13790 II
No full textPrskalice su poljoprivredni strojevi čija je glavna zadaća aplikacija kemijskih, ali i ne kemijskih sredstava
primjenjivanih u zaštiti bilja. S ciljem da se poboljša kontrola hrane unutar EU, 2000. godine potpuno mijenja
prijašnji zakon novijim strožim zakonom (Generalni zakon o hrani) koji je zamišljen kako bi pružao informacije
potrošačima kako je proizveden određeni poljoprivredni proizvod kojeg kupuje. Kao plod istraživanja 12. veljače.
2014. godine izglasan je „Zakon o održivoj uporabi pesticida“ kako bi došlo do prilagodbe sa standardima
Europske unije. Pregled strojeva koji se koriste se odvija prema normi EN 13790 koja se koristi od 2003. godine.
Podijeljena je na dva dijela EN 13790 – I koja se koristi za ratarske prskalice i EN 13790 – II koja se koristi za
raspršivače odnosno atomizere. Krajem osamdesetih godina dvadesetog stoljeća počinje provjera ispravnosti rada
prskalica i raspršivača u Europskoj Uniji. Na području Krapinsko – zagorske županije smo 04.05.2021. proveli
testiranje 7 strojeva za zaštitu bilja. Od 7 ispitanih strojeva bilo je 5 ratarskih prskalica i 2 raspršivača. Vizualno
su svi strojevi izgledali uredno, čisto i dobrog općeg stanja, što se tiče ispravnosti manometara kod jednog stroja
smo primijetili kvar, dok su ostali bili ispravni, crpka je kod svih strojeva bila ispravna. Mlaznice su kod ratarskih
prskalica bile ispravne na dva ispitivana stroja, dok su na njih tri mlaznice bile neispravne. Kod raspršivača
mlaznice su bile ispravne. Poprečna raspodjela tekućine je na svim ratarskim prskalicama bila zadovoljavajuća,
kod dvije prskalice imao i izvrsne rezultate sa < 10 %. Ventilatori na oba raspršivača su bili ispravni.Sprayers are agricultural machines whose main task is the application of chemical, but also nonchemical agents used in plant protection. In order to improve food control within the EU, in 2000 it completely
changed the previous law to a newer stricter law (General Food Law) designed to provide consumers with
information on how a particular agricultural product they buy was produced. As a result of research on 12 February
2014., the "Law on Sustainable Use of Pesticides" was passed in order to comply with European Union standards.
Inspection of machines used is carried out according to the standard EN 13790, which has been used since 2003.
It is divided into two parts, EN 13790 - I, which is used for field sprayers and EN 13790 - II, which is used for
atomizers. At the end of the eighties of the twentieth century, the verification of the correct operation of sprayers
and sprayers in the European Union began. In the area of Krapina-Zagorje County we were 04.05.2021. conducted
testing of 7 plant protection machines. Of the 7 machines tested, 5 were field sprayers and 2 atomizers. Visually,
all machines looked neat, clean and in good general condition, as for the correctness of the manometers in one
machine we noticed a malfunction, while the others were correct, the pump was correct in all machines. The
nozzles on field sprayers were correct on two tested machines, while on them three nozzles were defective. At the
stomizers the nozzles were correct. The transverse liquid distribution on all field sprayers was satisfactory, with
two sprayers also having excellent results with <10 %. The fans on both stomizers were working
TESTING TECHNICAL SYSTEMS IN CROP PROTECTION ACCORDING TO EN 13790 NORM
Get PDFU svrhu dostizanja standarda te prilagodbe propisima Europske unije dana 12. veljače 2014. godine na snagu stupa Zakon o održivoj uporabi pesticida. Poglavlje broj 6 ovog zakona odnosi se na strojeve za primjenu pesticida gdje između ostalog propisuje pregled tehničkih sustava u zaštiti bilja prema normi EN 13790. Cilj istraživanje je doći do saznanja o tehničkoj ispravnosti strojeva za zaštitu bilja na području Općine Trpinja te tehničkim pregledom utvrditi trenutačno stanje testiranih strojeva. Na temu testiranja tehničkih sustava u zaštiti bilja proveden je velik broj istraživanja, kako u inozemstvu, tako i u Republici Hrvatskoj. Za potrebe ovog rada, kao primjeri, korištena su dva rada: „Provedba testiranja tehničkih sustava u zaštiti bilja u Istočnoj Hrvatskoj“ autora dr. sc. Vjekoslava Tadića i suradnika, te „Istraživanje ujednačenosti površinske raspodjele tekućine ratarskih prskalica“ autora prof. dr. sc. Đure Banaja i suradnika. Za provedbu testiranja korištena je oprema Zavoda za mehanizaciju, Poljoprivrednog fakulteta u Osijeku. Zavod posjeduje svu potrebnu opremu za provedbu testiranja tehničkih sustava u zaštiti bilja po normi EN 13790. Testirano je ukupno 28 tehničkih sustava u zaštiti bilja. Većinom su to nošeni strojevi, malog obujma spremnika te malog radnog zahvata. Iz rezultata je vidljivo kako samo 11 prskalica zadovoljava kriterije koje postavlja norma EN 13790. Najviše prskalica je neispravno zbog mlaznica i manometara. Zamjena mlaznica i manometra propisnim nije složen zahvat te ne iziskuje velika sredstva. Ukoliko bi se vlasnike strojeva uspjelo motivirati na propisno održavanje strojeva, sigurno bi znatno više bilo ispravnih, odnosno u skladu sa standardima koje propisuje norma EN 13790.In order to meet the standards and to implement EU rules, on 12 February 2014 came into force the Law on the Sustainable Use of Pesticides. Chapter No. 6 of this Law refers to machinery for the application of pesticides where, among other things, requiers review of technical systems in plant protection according to EN 13790. The aim of the research is to gain an insight of the technical condition of machinery for plant protection in the municipality Trpinja and to determine the current state of the tested machines by technical inspection. On the subject of testing technical systems in plant protection a number of studies has been carried out, both abroad and in Croatia. For the purposes of this paper, as an example, two articles were used: "Implementation testing of technical systems of plant protection in eastern Croatia" by dr. Sc. Vjekoslav Tadic and associates, and "Research uniformity of the distribution of surface liquid spraying machine" by prof. dr. sc. Duro Banaj and associates. To implement the test, we used the equipment of the Institute of Mechanics, Faculty of Agriculture. The department has all the equipment necessary to implement the testing of technical systems in plant protection according to EN 13790. A total of 28 technical systems of protection of plants were tested. They are mostly three-point hitch attach machines, small volume tanks and small working width. The results show that only 11 sprayers meets the criteria set by the EN 13790. Most sprayers is malfunctioning because of the nozzles and manometers. Replacement of the nozzles and manometer with the properly working ones, is not a complex procedure and does not require large resources. If the owner of the machine was managed to motivate on the proper maintenance of machines, there would be much more correct machines, and in accordance with the standards prescribed by the EN 13790
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