Energy Efficiency Class Research Articles

Determination of air permeability of buildings

The air permeability of the building determines the level of energy efficiency of the building. The regions of the European Union are approaching NZEB standards and passive house standards. The Ukrainian regulatory framework for airtightness does not meet European standards for energy-efficient buildings and will require updating, as there will be an increase in the wind permeability of the building, and the increase is possible to the normatively permissible value, increased air permeability and energy efficiency. The permeability is expressed by the value of the air flow in cubic meters per year per square meter of the area of the outer shell of the booth when there is a pressure difference in the internal air of 50 Pa. Ait permeability will need to be specified by parameter q50 [m3/(h·m2)] instead of n50 [h – 1]. All countries of the European Union may use the q50 [m3/(h·m2)] parameter in their standards. Exclusions are Lithuania and Ukraine, where the actual air permeability is determined by the parameter n50 [h – 1]. Based on the Ukrainian standard for air permeability, air permeability is calculated by n50 [h – 1]. For energy efficiency class C, values n50 < 2.0 [h – 1] are allowed, which is approximately the same value as q50 < 5.0 [m3/(h·m2)]. Following the Lithuanian standard, which also corresponds to the vicoristics n50, where n50 < 1.0 h – 1, which is approximately the same value as q50<2.5 [m3/(h·m2)]. It is proposed to establish new standard values for the air permeability and energy efficiency in line with European standards. The results of penetration tests of 24 objects of different heating volumes and energy efficiency classes were analyzed. It’s shown that lovering the energy efficiency class disharmonises the n50 and q50 values. The results allow proposal to set the normative value n50 < 2.5

Ways to overcome the barrier during the transition of asynchronous motors to the energy efficiency class IE5

Purpose. To provide a comprehensive analytical review on ways to increase the energy efficiency of induction motors and identify those suitable for transitioning fixed speed induction motors to IE5 level. Methodology. A thorough study of research and development in the field of increasing the energy efficiency of induction motors for various purposes was conducted. The experience of the development of traction induction motors of electric vehicles as dynamically developing is extrapolated. Results. It was established that the main limiting factor in increasing the energy efficiency of induction motors to the IE5 level is its thermal state. Analysis of ways to improve the efficiency of induction motors indicates the need for their complex application. It is most expedient to optimize and improve the elements of the air-cooling system of induction motors. To carry out the research, it is necessary to comprehensively apply electromagnetic and temperature field modeling systems of induction motors. Given certain shortcomings of thermal models of induction motors, it is necessary to combine modeling with experimental studies using both classical temperature sensors and the method of thermography. Originality. The combination of modern methods of modeling the thermal state of induction motors and experimental studies makes it possible to determine reserves for increasing the efficiency of existing motors. Using these results, it is possible to improve induction motors to the IE5 efficiency level. Practical value. Manufacturers and researchers see difficulties with the transition of induction motors of industrial purpose to the IE5 efficiency level, so they focused their attention on synchronous electric motors. The results of our research prove that, despite certain barriers, this transition can be made, albeit with certain difficulties.

Analysis of the regulatory and legislative base of Ukraine and the European experience in conducting energy audits of buildings

The article analyzes the regulatory and legislative base for the energy efficiency of buildings. It identifies the main areas for improving energy efficiency by improving the process of energy audit, as well as improving the system of indicators that determine the airtightness of the building and preservation of comfortable conditions for human stay in the room. The relevance of the work is determined by the problem of low energy efficiency of the housing stock of Ukraine, which affects the rational consumption of energy, necessitates the introduction of various measures aimed at rationalizing energy use in general and buildings in particular, setting maximum permissible energy consumption rates for buildings and strengthening relevant control. The imperfection of the regulatory and legislative base in the field of energy efficiency, the need to develop a state standard for the design of buildings with increased air permeability, the development of a methodology for determining the air permeability of a building, the legislative establishment of minimum requirements for building airtightness, the development of a methodology for testing buildings for airtightness, and the imperfection of the methodology for conducting an energy audit of a building form the basis for further research. To improve the energy management of buildings, it is proposed to introduce mandatory testing of the building for airtightness, which will standardize approaches to energy management and compliance with the relevant requirements for building airtightness will lead to an increase in the energy efficiency class of buildings. Keywords: energy efficiency, energy audit, air permeability, airtightness.

Application of ecodesign policy and energy labelling to improve energy efficiency and quality of LED light sources

Ecodesign, which provides for measures to reduce negative impacts on the environment and increase the functionality of LED light sources, is one of the priority areas of the energy saving policy. The paper presents the results of a study of commercial samples of non-directional LED lamps of various brands for compliance with the Commission Regulation (EU) 2019/2020 on establishing the requirements for the ecodesign of light sources and the Declared Commission Regulation (EU) 2019/2015 on the energy labelling, which came into force in 2021. It is shown that the light output of the tested batches of lamps with a power of 5–12 W is in the range of 90–120 lm/W, which corresponds to the energy efficiency classes, according to the new rating scale of the Commission Regulation (EU) 2019/2015, F and E. Over the past decades, the light output of the lamps entering Ukraine has increased by more than 30%. Quality indicators of light have also been improved: all tested lamps have a general colour rendering index of Ra > 80; in five of eight batches of lamps, the colour unevenness does not exceed the 3-degree McAdam ellipses; and only in one batch, individual lamps exceed the 6-degree ellipse. All tested lamps meet the requirements for the level of flickering (PstLM < 1) and the level of visibility of the stroboscopic effect (SVM < 0.4). Individual non-compliances of the lamps with the established requirements were also noted, in particular, lamps with a power of 11 and 12 W do not meet the power factor cos φ1 – some manufacturers do not fully declare the characteristics of their products. Most of the lamps have a low special colour rendering index R9. Conclusions about the effectiveness of the ecodesign policy and energy labelling in increasing the energy efficiency, quality and safety of LED lamps have been made.

Impact of Economic Awareness on Sustainable Energy Consumption: Results of Research in a Segment of Polish Households

This manuscript explores the relationship between the economic awareness (as a part of energy awareness) of Polish households and their sustainable energy consumption practices. Sustainable consumption is measured by the frequency of behaviors such as turning off electrical devices when not in use, removing mobile device chargers from sockets, switching off lights when leaving a room, preferring showers over baths, using washing machines and dishwashers only when full, and purchasing energy-efficient appliances and light bulbs. Economic awareness is gauged through variables such as knowledge of electricity tariffs, understanding of electric bill components, awareness of electricity prices, exact knowledge of electricity expenses, electricity usage in kWh, knowledge of effective energy-saving methods, and familiarity with the energy efficiency classes of appliances and light bulbs. This study presents profiles of households with high and low economic awareness regarding their electricity expenditures and examines how these profiles differ in their sustainable energy consumption behaviors. This research is based on a survey of 1407 Polish households conducted online in 2023. Data collected from the survey were subjected to statistical analysis and are presented in tables and graphs. The findings are discussed in the context of the existing literature in the field, highlighting the implications of economic awareness on sustainable energy consumption practices. This research contributes to understanding how economic knowledge influences energy-saving behaviors among Polish households, providing insights for policymakers and energy conservation initiatives. One of the key findings of this paper is the significant association between economic awareness, energy-saving knowledge, and the adoption of sustainable energy consumption behaviors among Polish households. This study reveals that households with higher levels of economic awareness demonstrate a notably higher frequency of practices related to sustainable energy consumption compared to those with lower economic awareness. Similarly, households equipped with greater knowledge about energy-saving techniques exhibit a higher propensity to adopt energy-efficient behaviors. This underscores important roles of economic literacy and education in fostering behavioral changes towards more sustainable energy practices, highlighting the importance of targeted interventions and educational campaigns aimed at enhancing economic awareness and promoting energy-saving knowledge among consumers.

Analysis of measures to increase the energy efficiency of educational buildings of the national university of water and environmental engineering

The implementation of energy-efficient measures at the National University of Water and Environmental Engineering (NUWEE) was started since 2000. The buildings of NUWEE are located in different parts of Rivne city and Rivne region. Buildings № 1-7 were selected by the Ministry of Education and Science of Ukraine for financing their thermal modernization as part of the loan project "Higher Education of Ukraine. Energy efficiency and sustainable development" with the aim of increasing their energy efficiency. The authors analyzed the measures to increase the energy efficiency of the educational buildings of the NUWEE, namely, the installation of thermal insulation of facades, roofs, floors on the ground and first surfaces, replacement of windows and doors, installation of thermal insulation of pipelines, modernization of automated thermal energy regulation units (ATERU), heating system and lighting, implementation of the energy monitoring and dispatching system, installation of the ventilation system with exhaust air heat recovery. Implementation of the proposed measures will reduce energy consumption and related costs by 60 %, namely by 6,232 MWh/year (compared to the baseline level of energy consumption of 10,286 MWh/year). It will result increasing of the buildings’ comfort and functionality. After the implementation of the described measures, the increase of the energy efficiency class of educational buildings is predicted. The implementation of energy-efficient measures will also lead to the reduction of greenhouse gas emissions by 50 %, namely by 1,648 t/year. Measures that can pay off as soon as possible are the implementation of thermal insulation of pipelines, modernization of ATERU and lighting, implementation of energy monitoring and dispatching systems. The longest payback period will require the installation of ventilation air heat recovery, but this measure is necessary in view of the current reduction in heat energy costs for heating the external supply air in the cold period of the year.

Analysis and evaluation of energy efficiency of a shrinkwrap-packer

Since some years, European companies are interested in the issue of energy saving. In such context, a classification of industrial machines from the energetic point of view is becoming more and more important; currently, in the industrial context, no similar classifications exist. The aim of this work is to formulate a standard method to evaluate the energy performance of an industrial machine, such as a shrinkwrap-packer. To this purpose, we studied a shrinkwrap-packer produced by OCME S.r.l, a mechanical machinery company located in Parma (Italy). Specifically, the shrinkwrap-packer was analyzed in terms of energy dissipations and other aspects related to the energy source utilized to power the oven. As a result, we propose a general procedure that allows to compare different solutions from different perspectives related to energy efficiency. More precisely, we include three key performance indicators (KPIs) of energy efficiency, to build a comprehensive evaluation model. The first KPI concerns the energy efficiency class of the oven, the second KPI takes into account the impact of the oven on the work environment and the third one is an index of degradation of the energy resource utilized. A Global Index of Energy Efficiency (GI) is finally computed as the area of a triangle represented on a radar diagram on three axes, one for each KPI.

EN Improving the energy efficiency of refrigeration equipment with a direct sales function

The increased use of refrigerants with low global warming potential GWP over the past decade indicates that manufacturers are already making gradual replacements with refrigerants with reduced environmental impact. Thus, in addition to HFC gas phase-out requirements, most EU countries are pursuing a trend to reduce the energy consumption of refrigeration appliances. Such countries restrict the import of equipment that does not meet the energy efficiency requirements. This paper presents the ecodesign of refrigeration equipment in relation to the requirements of the sales market using the Regulation on Conformity Assessment Procedure. HVAC&R equipment contributes to GHG emissions in two ways: directly through refrigerant leakage or venting, and indirectly through electricity use, the latter accounting for up to two-thirds of GHG emissions. The paper compares the energy and environmental characteristics of refrigerants R404a and R290 in freezer M200V. The experimental results show that the highest COP va­lues in the system for R404a and R290 are 3.02 and 3.19, respectively. Possibilities of complete transition from F-gases to natural analogues with GWP ≈ 0 are shown. At application of R290 its advantages on energy efficiency are obvious - reduction of electric power consumption of freezing chests on 8,9 %, influence on environment R404A – GWP=3260, R290 – GWP=3. The calculation of energy efficiency class for freezing chest was made. To improve energy efficiency, a number of design modifications were made: the density of the thermal insulation material and the compressor were changed. The energy consumption of the modified version at the second climatic class was measured at 1.23 kW/24h, and the energy efficiency coefficient according to the calculation EEI =34.904, which corresponds to the energy efficiency class «C».

Проектирование зданий с энергосберегающими конструкциями с позиций управления жизненного цикла объекта строительства

The design of buildings, especially during the layout and development phase of low heat and energy structures, requires a distinct identification of energy efficiency and performance objectives. Also it should consider the flow and inflow of energy and thermal systems. It allows the project to comply with the client's and designer's requirements regarding the energy efficiency class. The required energy base for the development of construction objects is established by observing a number of approaches. These include the following ones: functional - facilities are convenient for the process; technical - facilities protect people from harmful effects; architectural and artistic expressiveness - facilities have a favourable effect on the persons’ psychological condition; economic - the building uses maximum useful area with minimum labour, financial and time costs on its construction. In terms of cost-effectiveness, the requirements apply to costs over the facilities life cycle.

MODERNIZATION OF THE ELECTRIC DRIVE OF PUMPING UNITS OF THE DISTRICT HEATING NETWORK IN THE CONTEXT OF INCREASING THEIR ENERGY EFFICIENCY

Quantitative and qualitative indicators of the modernization of the electric drive of a pumping unit of a network with throttle control of the coolant supply of a centralized heat supply system are determined. The possibility of modernizing the electric drive by replacing outdated electric motors of energy efficiency class IE1, which are still used in electric drives of pumping units, with electric motors of energy efficiency classes IE2 and IE3 from different manufacturers, has been substantiated. The energy consumption was calculated based on the technical data of the pump and electric motors provided by the manufacturers and includes the calculation of the energy consumption of pumping units in a typical operating cycle typical for district heating networks, which involves operation at reduced load for a long time. Comparative calculated data on the daily and annual energy consumption of the considered electric motors in a typical operating cycle of a pumping unit, with respect to the least energy-efficient electric motor among those considered, were obtained. The practical significance of the results obtained is to understand that the selection of an electric motor by efficiency at variable load, i.e., actually on the basis of the IE energy efficiency class assigned in accordance with the IEC 60034-30-1 standard, is incorrect, It is substantiated that the choice should be made using the efficiency interpolated by the method of polynomial interpolation of the motor loss curve, while taking into account the economic feasibility of choosing an electric motor between energy efficiency classes, in this case IE2 and IE3, and different manufacturers.

Evaluation of the Energy Efficiency Class of an Industrial Facility: A Rating System and a Scale of Sustainable Development

This article examines the issues in assessment of the energy efficiency of industrial facilities, which have not yet been scientifically resolved, in contrast to the widely used approaches to assessing residential buildings, which are similar in many countries of the world. The sequence of the study was determined in combination with the characteristics of the methods used, the leading of which was the expert survey method. Based on the analysis of the collected statistical information, the significance of energy efficiency indicators was agreed upon and assessed for three groups: first—industrial building, second—technological processes, and third—ensuring the environmental friendliness and energy efficiency of an industrial facility. The weight of each group was also determined based on an expert survey. This made it possible to calculate the specific weights of the indicators and formulate a rating scale. The principle of assigning points for each indicator is determined depending on the deviation of actual values from standard values for quantitative indicators and according to the characteristics of the object of analysis for qualitative indicators. The result of the study was the positioning of classes on the scale of energy efficiency within the established boundaries based on experimental data.

Parametric study of an active-passive system for cooling application in buildings improved with free cooling for enhanced solidification

The present study introduces an active-passive system (APS) with phase change material (PCM) integrated into the substructure of the internal walls and ceiling for cooling. To ensure sufficient cooling effect of the system during the daytime cycle, the system must solidify completely during the nighttime cycle and operation costs comparable to the ones of conventional cooling systems. An air gap was formed between the primary wall and ceiling and the PCM substructure and ventilated with the cool outdoor air during the nighttime cycle. A parametric study was performed using ANSYS Fluent followed by the energy performance and operation cost analysis. Different inlet air temperature scenarios (15–20 °C) were tested (suitable PCM thermal characteristics). The required solidification-time of PCM was determined. The model is validated against the experimental tests. The results show that with the current configuration, the PCM plates can be sufficiently solidified at supply air temperatures of 17 °C and below. If the system is ventilated with inlet air temperatures above 17 °C, additional cooling options must be considered. The study also determines the energy performance of the system under the chosen conditions and compares its feasibility to the conventional cooling systems (energy efficiency class A+++ and G air-conditioning device).

Building Energy Passportization in Azerbaijan

The operating energy costs of buildings account for approximately 70-80% of the total costs throughout the entire life cycle of a building. From the moment putting the building into operation, it begins to consume energy, mechanical, electrical, and natural resources. In buildings, all construction and technical systems naturally degrade over time, both in terms of performance and efficiency, i.e. operating and maintenance building costs are rising, energy consumption is increasing, and microclimate quality is declining. As a solution to this issue, it is possible to consider building energy passport, as a tool to control the optimal building operation according to the indicators of the building passport and as an encouragement way of cities' sustainability. The building passport by its energy efficiency (BEP) and rational use of material resources is a special document- a certificate that contains information about the geometric and technical parameters of the building, its functional purpose, design solutions, thermal characteristics, and energy performance. This paper discusses the current state of the building passportization process in Azerbaijan, and analyzes the existing shortcomings. Categories and component parts of BEP, types and levels of building information and data, scheme of inputs and extractions data during the building life cycle, key tasks of BEP, and strategic actions for the successful development of BEP are given. Building energy efficiency rating classes are calculated, and the main procedures to enhance the energy efficiency class are given. The requirements for experts who carry out the buildings` passportization are systematized.

REDUCED HEAT LOSS THROUGH WINDOW STRUCTURES

The results of theoretical and experimental studies of heat transfer through the window structures of the building are presented, the thermal characteristics of the windows are established and the level of heat loss realized through them is estimated. To determine the heat transfer resistance of two-chamber double-glazed units, numerical modeling of radiative-convective heat transfer is performed, taking into account the thermal conductivity of the gas layer between the glasses. Natural free convection of the gaseous medium in the double-glazed chambers occurs as a result of the temperature difference between the side glass surfaces of the chamber. Modeling is performed by numerically solving the system of fluid dynamics and energy equations for the air layer and glass. On the inner surfaces of the chambers, conditions of the fourth kind are set, which take into account the radiation and conductive components of the total heat flow coming from the glass surface. The results of simulation of heat transfer through double-glazed windows with ordinary glass indicate that about 60 % of heat is transferred by radiation. Therefore, an effective measure to reduce heat loss through windows is to reduce the radiation component of the total heat flow by applying a low-emissivity coating to the inner surfaces of the glass unit. This makes it possible to reduce the total heat flow (and, accordingly, heat loss to the environment) by 20–34 %, depending on the number of glass surfaces with this coating. Conducted independent experimental studies confirm the modeling results. In order to comply with the current requirements of state building regulations and to achieve the energy efficiency class of type C buildings (specific heat consumption for heating 1 sq. m of usable area is less than 75 kWh), for the climatic conditions of Kyiv, it is recommended to use double-chamber windows with two low-emission coatings with the formula of the glass unit: 4M1-10-i4M1-10-i4M1. Bibl. 22, Fig. 8.

ПОКАЗНИКИ ЕНЕРГОЕФЕКТИВНОСТІ ГРОМАДСЬКОЇ БУДІВЛІ

The relevance of paying attention to the energy efficiency of buildings, which will reduce the consumption of fossil fuels and electricity and reduce harmful emissions into the environment, is shown. The energy efficiency indicators of the public building were analyzed, namely the thermal resistance of the enclosing structures, the specific energy demand for heating, cooling and hot water supply, the specific energy consumption of the building for heating and cooling, the specific consumption of primary energy and the specific emissions of greenhouse gases.The effect of increasing the normative thermal resistance of the outer wall of the building on the required thickness of the insulation was evaluated. It is indicated that under the conditions of a large facade glazing ratio and compliance with the regulatory thermal resistance of the fences, the building does not meet the requirements for specific energy consumption for heating, cooling and hot water supply.The influence of the heat source for heating the building on its specific energy consumption, energy efficiency class, specific consumption of primary energy and specific emissions of greenhouse gases was studied. Considered options for using a gas boiler, a condensing gas boiler, electric heaters, a biomass pellet boiler and connection to a centralized heat supply system. The effectiveness of the implementation of reversible heat pump equipment for heating and cooling of buildings is substantiated

Evaluating Reduction in Thermal Energy Consumption across Renovated Buildings in Latvia and Lithuania

Currently, the optimization of thermal energy consumption in buildings is considered a suitable alternative in the construction of new buildings, as a result of which the overall energy efficiency of the building increases. Thus, this study examined the efficiency and efficacy of different building renovation packages conducted across several buildings in Latvia and in Lithuania (across a larger building stock). In the first section of this study, 13 multi-apartment residential houses with 3 building renovation packages have been investigated in the city of Daugavpils, Latvia, in order to determine the actual reduction in heat energy consumption across each of the renovation implementation packages. The study findings indicate that changes in Latvian building regulations regarding insulation thickness did not significantly impact thermal energy consumption in fully renovated buildings. However, the combination of facade renovations, upgraded heating systems, and improved ventilation systems resulted in substantial energy savings, with an average reduction of 50.59% in thermal energy consumption for space heating across the reviewed multi-apartment residential building stock. In the following section of this study, the impact of the Energy Performance of Buildings Directive (EPBD) on building energy efficiency in Lithuania has been examined. The results show that over a 10-year period in the 2000s, Lithuanian building stock experienced a 20% increase in energy efficiency, followed by an additional 6.3% increase between 2010 and 2016. The mandatory requirement for renovated buildings to achieve a minimum energy efficiency class has resulted in significant reductions in energy consumption for heating purposes. The findings underscore the effectiveness of building renovation packages and the EPBD regulations in enhancing energy efficiency and promoting sustainable building practices. The importance of heat metering, consideration of indoor air temperature, and the need to address indoor air quality during renovations were also highlighted.

ASYNCHRONOUS ELECTRIC MOTOR WITH SINGLE-PHASE STATOR WINDING

The current standard considers the efficiency of electric motors only in terms of power efficiency and does not pay attention to the so-called economic efficiency - the power factor that affects the loss of electricity in the motor supply network and depends on its energy excellence.This ill-considered approach to establishing the energy efficiency class is a significant shortcoming of the European standard and requires its refinement. The single-phase power supply network in housing and communal services has led to the fact that modern motor compressor units of refrigerators, air conditioners, etc. are equipped with single-phase asynchronous electric motors. An innovative single-phase asynchronous AC motor for motor-compressor units of household appliances is considered in the paper. The stator winding of it is composed of two identical series-connected coils enclosed in half-slots of the stator with a spacious offset of 900.The phase shift of the currents in the coils is provided by a capacitor connected in parallel to one of the coils. The proposed motor is technological in production, has higher specific power and energy efficiency than existing models and meets the IE-3 class energy efficiency. Equivalent electrical circuit and vector diagram of currents for this motor have been developed and shown. They are intended for its mathematical simulation, calculation of static operating characteristics, analysis of dynamic properties at operation in the electric drive system, and also at the level of design work.

Spatial assessment of buildings energy consumption based on three-dimensional modeling of the urban environment

The article deals with the application of spatial assessment of urban buildings energy consumption (EC) and analyzing the results based on the urbogeosystems approach. Assessment of buildings EC involves establishing a correlation between their EC and the relevant geometric characteristics, in particular, the buildings height and volume. The authors propose the use of remote laser scanning data (LiDAR data) for the automated extraction of these characteristics of buildings with high accuracy. An original approach to processing and analyzing LiDAR data using the tools of the author's web-based GIS application for the purpose of buildings extraction and modeling is presented. The extracted building models contain their exact geometric characteristics and generalized architectural properties as attributes. The article presents a methodology for calculating the EC of buildings, which uses their geometric information, as well as information on their age and type, which are also correlated with the buildings EC. Based on the buildings geometry obtained from LiDAR data, the indicator of their usable area (intended for heating) is determined. To estimate EC, data on the buildings EC are taken from real meter readings, which are extrapolated to the calculated indicator of the buildings usable area. A semantic table is created that corrects the calculated building EC, depending on its age and type, and determines the final energy efficiency class of the building. According to the above methods, three-dimensional models of buildings for the cities of Amsterdam and Eindhoven were extracted and visualized, with the color scheme applied to the buildings reflecting their energy efficiency classes. The essence of the urbogeosystemic analysis of the urban environment in the context of the urban EC study is revealed. On the basis of the obtained visualization of the spatial distribution of urban EC, certain regularities of such distribution between individual urban buildings are identified and the factors influencing the level of this indicator are determined.

ANALYSIS OF APPROACHES TO DETERMINING THE QUANTITY OF THERMAL ENERGY FOR THE NEEDS OF HOT WATER SUPPLY IN THE ENERGY CERTIFICATION OF BUILDINGS

In Ukraine, at the legislative level, as part of the implementation of EU Directives, mandatory energy certification has been introduced for certain types of new and reconstructed buildings. In addition, in order to receive financing from various investment funds and the possibility of participating in state or local thermomodernization programs, it is necessary to perform their energy audit and justify energy-saving measures, assess the energy efficiency class. In Ukraine, there is a complex of regulatory acts, methodical documents, construction norms and standards in the field of energy certification, which is constantly updated. The national methodology for calculating energy efficiency indicators has been passed and the by-laws have changed several times, in particular, in the part of accounting for energy consumption for hot water supply, which in turn affected the energy efficiency class. The article evaluates the influence of different approaches to the calculation and accounting of additional revenues from hot water pipelines on the example of a residential multi-story building in Kyiv. As part of the research, a detailed energy survey was carried out using instrumental and analytical methods, the geometric, thermal and energy characteristics of the building were specified, and a set of measures to increase the level of energy efficiency was proposed. As part of the research, a detailed energy survey was carried out using instrumental and analytical methods, a calculation model was formed and a series of calculations was performed. The impact on the specific energy demand, total energy consumption and energy efficiency class of the existing building of changes in the regulatory framework, the features of taking into account utilized heat losses, the number of consumers is shown.

Developing a multi-level energy benchmarking and certification system for office buildings in a cold climate region

Energy benchmarking is an accurate tool to measure, monitor, and reduce end-use energy consumption in the building sector using comparison scenarios. Various studies have applied Bottom-Up energy consumption assessment to compare the energy performance of a group of buildings with a benchmark. The Bottom-Up method mostly relies on simulating an ideal building to develop a benchmark. However, this study has developed a Top-Down energy benchmarking methodology based on the actual energy consumption within a cluster of governmental office buildings. The method presents multi-level benchmarks to provide a detailed policy for improving the energy efficiency of buildings in the short or long-term. In an exploratory study, 26 office buildings in a cold climate region were investigated to identify the multi-level benchmarks. Four general benchmark levels were developed, including the ‘Best Practice, ‘Good Practice’, ‘Benchmark’, and ‘Poor Practice’. In addition, 15 energy efficiency classes were also introduced and applied as a base for developing the ‘Energy Performance Certificate’ method. The results indicate that the benchmark values for electricity and natural gas are 40 and 252 kWh/m2/yr, respectively, while the total energy benchmark is 292 kWh/m2/yr. According to the benchmarking results, 69% of the case studies were inefficient, 23% were labeled ‘C’, and no cases were labeled ‘A’ or ‘B’. The multi-level benchmarking system can provide quick and clear guidance for building designers, operators, and government regulation/enforcement agencies; thus, it can apply at local, regional, and international levels. These benchmark levels establish reference points for measuring and rewarding good performance, on the other hand, it recognizes poor-performance buildings and prioritizes them for energy efficiency improvement. The method can be replicated in various climates and urban scales.