Filkoski, Risto
Preferred name
Filkoski, Risto
Official Name
Filkoski, Risto
Main Affiliation
Email
risto.filkoski@mf.edu.mk
risto.filkoski@mf.ukim.mk
risto.filkoski@gmail.com
Scopus Author ID
AGM-5469-2022
Researcher ID
0000-0002-3743-318X
15 results
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Item type:Publication, Energy efficiency in complex buildings(IOP Publishing, 2020-01-24); ; Thermal energy performance of a certain building refers to the process of modelling the energy transfer between the building and its surroundings. The objective of the present work was to analyze the energy performances of complex buildings in terms of energy efficiency. Healthcare buildings are a typical example of complex objects, both from a construction and from a thermo-technical aspect, since they usually need heat and cold generation and distribution systems and facilities. For the purpose of the present analysis, a complex consisting of 16 hospital buildings has been evaluated from the energy efficiency viewpoint. Numerical simulation has been conducted to identify the baseline energy consumption of the considered healthcare buildings. The data have been further processed for analysis and comparison of baseline scenario with the scenario for energy efficient renovated buildings. The results from the analysis show that energy efficient complex healthcare buildings may reach operation energy savings up to 50% compared to baseline situation where the buildings are operating with inefficient heating and electrical systems. The investments simple payback period of the proposed energy efficiency measures is between 5-6 years. Implementation of renewable energy system for sanitary hot water preparation, might address issues related to energy security, i.e. dependency on the energy imports by reducing expenditures on energy, as well as might reduce the consequent environmental impact. The results of the energy efficiency measures implementation in the considered healthcare buildings show significant improvements, resulting with lower energy cost for the buildings, reduction of fossil fuels use and reduction of CO2 emissions up to 45%. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A model for techno-economic optimization and environmental sustainability of the heating structure in an urban area(Društvo termičara Srbije, 2017); ; ; ; The objective of the present work is to conduct techno-economic evaluation of different available methods and types of heating in urban areas, having in the forefront the impact on the environment. Several important aspects have been envisaged within the analysis: technical feasibility, investment costs, operating and maintenance costs, as well as the environmental impact assessment. The main goal of the work is to provide reliable information and indicators for selection of optimal sustainable type of heating in the city of Skopje as a major urban area. The actual situation in terms of air pollution in Skopje has been briefly outlined. The current situation regarding the ways of thermal energy supply for heating in Skopje is presented. A complex mathematical model has been applied for the purposes of a comparative analysis between different heating methods, that takes into consideration the necessary techno-economic and environmental aspects of the heating methods and systems. Furthermore, the model has been adapted and applied as for the conditions of the city of Skopje, offering a strong guidelines for selection of the best way of heating in different parts of the city, depending on the local urban, infrastructural, technical and environmental conditions. The results show a significant advantage of the central heating system in relation to the other types of heating, from engineering, financial and environmental viewpoint. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Thermal characteristics of combined compressor - ejector refrigeration/heat pump systems for HVAC&R(National Library of Serbia, 2024) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Heat transfer between heated, partially heated and non-heated residential units in buildings(IOP Publishing, 2020-01-24); ; Space heating cost allocation according to actual consumption can be one possible motivating factor for saving energy in residential and other buildings. As a consequence of the exclusion of a certain number of users in collective housing units from the central heating supply system in the city of Skopje, the problem of heating cost allocation and collection of the fixed part of the heat energy payment has arosen. The subject of the analysis in this study was the heat transfer in buildings, with the main focus on the issue of heat transfer rate between residential units with different internal temperatures, such as from heated to unheated or partly heated apartments in collective building objects. The purpose of the analysis was to assess the mutual energy interaction between the completely or partially excluded apartments from the central heating system and the adjacent apartments connected to the central heating system. This is done by simulating the thermal characteristics of typical buildings that are representatives of new (insulated) and old (un-insulated) buildings. For the simulation purposes, the external average daily and monthly temperatures were obtained based on the perennial outdoor temperatures measured in Skopje and additional series of input data that are characteristic for the city were used. For the value of the internal temperature in the dwellings the value for the standard internal design temperatures are predefined. As results of the simulation, values were obtained for the annual heat gains (in kWh/year) and the specific heat gains (in kWh/m2year) of the excluded apartments from the system of central heating through the enclosures (internal walls, ceiling and floor) of the adjacent apartments that are connected to the system for central heating and vertical hot water pipelines for an isolated and nonisolated buildings. In order to obtain a clearer picture, in the study are considered different configurations and positions of apartments in the building. As an indicator for each considered apartment, the ratio of the received thermal energy of the disconnected apartment to the required energy for its heating is calculated. Based on the obtained results, appropriate conclusions were drawn regarding the reduction of the necessary energy for heating of the excluded apartments, as a consequence of the thermal gains through the walls of the neighboring apartments that are connected to the heating system. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Optimisation of Heating Structure in Urban Areas(Faculty of Mechanical Engineering in Nis, 2017-10); ; ; The present work deals with optimization model for selection of optimal heating structure in urban areas also considering the environmental aspects. Optimization model was developed, aiming to facilitate the decision making during selection phase of heat sources locations and defining the boundaries of their action at the pre-design phase of heat supply schemes development of settlements. Within the model is performed comparative analysis between ten heating systems, whereas as leading criteria in the comparison procedure are considered heat load density per unit of area, techno-economic aspects and environmental impact. The optimization result actually defines the optimal heating system type in regard of the value for the heat load density per unit area. The model provides possibility in defining standard values of heat density indicators, according to which can be assessed the economic feasibility of implementing district heating system for the selected urban area. The less value of heat density in the system, the higher specific costs for generation, distribution and transmission of heat energy. Furthermore the model is applied and verified for the local urban, infrastructural, technical and environmental conditions for the city of Skopje. Determination process of optimal heating structure has holistic approach, where beside techno-economic aspects and feasibility the environmental aspect of different heating systems is considered as a major factor (threat) in air pollution. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Environmental benefits from optimisation of sustainable heating systems in Skopje(Balkan Environmental Association (B.EN.A.), 2017); ; ; Main aspect and contribution of this paper is in obtaining relevant information and indicators on the environmental picture of the city of Skopje in regard of defined techno-economic optimum type of heating for specific regions of a larger urban area. Environmental benefits of the techno-economic approach are presented from the analysis of different methods and types of heating in urban areas, i.e. current and potential (possible) heating systems in Skopje. To meet the goal, a complex software package is developed used for optimisation of the heating structure in Skopje, composed of several sub-programs for analysing the energy, economic and environmental characteristics of the different heating systems implemented in each of the regions mapped for the urban area of Skopje. The obtained results from the defined techno-economic optimum model for heating and anticipated implementation plan indicate that there will be significant improvement in the pollution in Skopje in a relatively short period. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Thermal characteristics of combined compressor - ejector refrigeration/heat pump systems for HVAC&R(National Library of Serbia, 2023) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Techno-economic and environmental optimization of heat supply systems in urban areas(National Library of Serbia, 2018); ; The present work deals with an optimization model for selection of optimal heating structure in urban areas also considering the environmental aspects. The optimization model was established in order to facilitate the decision making during selection phase of heat sources locations and defining the boundaries of their action at the predesign phase of heat supply schemes development of settlements. Within the model is performed comparative analysis between ten heating systems, whereas as leading criteria in the comparison procedure are considered heat load density per unit of area, techno-economic aspects, and environmental impact. The optimization result actually defines the optimal heating system type in regard of the heat load density per unit area. The model provides possibility in defining standard values of heat density indicators, according to which can be assessed the economic feasibility of implementing district heating system for the selected urban area. The less value of heat density in the system, the higher specific costs for generation, distribution, and transmission of heat energy. Further-more, the model is applied and verified for the local urban, infrastructural, technical and environmental conditions of the city of Skopje. The process of determination of optimal heating structure has holistic approach, where, beside techno-economic aspects and feasibility, the environmental aspect of different heating systems is considered as a major factor (threat) in air pollution. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, INTEGRATION OF LARGE‐SCALE HEAT PUMPS IN THE DISTRICT HEATING SYSTEM OF SKOPJE(University of Banja Luka, Faculty of Mechanical Engineering, 2021-05); ; ; Monika Uler-ZefikjIn the residential sector in EU countries space heating and domestic hot water system participate with more the 80% in the final energy consumption. Cost‐effective and energy efficient option for residential and commercial buildings is DHC which is currently dominated by fossil fuels, such as coal and gas. Upgrading existing systems with integrating renewable technologies can lead to significant benefits regarding climate change mitigation, energy security and human health. The main aim of this paper is analyzing the possibilities for integrating heat pump together with thermal storage in the district heating system in Skopje, R. North Macedonia, considering current network system, growing population, climate conditions and pollution issue. Different scenarios will be analyzed by changing the COP of the heat pump in order to get an overview of the most feasible option taking into consideration the heat production, electricity consumption and payback period. The energy model is developed and analyzed for the part operated by Balkan Energy Group. It tends to provide insight of the benefits provided by the system upgrade and cost analysis for installation, operation and maintenance of the equipment. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Sensitivity analysis for integration of renewable energy sources into district heating systems(National Library of Serbia, 2024);