Developing Multi-Criteria Model for the Protection of Cultural Built Heritage in Serbia from the Aspect of Energy Recovery of the Buildings

Contemporary society and modern living in urban areas strive for more sustainable environments, respecting the past, history and their remains. Intangible and tangible cultural heritage has become an important urban resource for city promotion as well as a trigger for economic and social city development. Built heritage, as part of cultural heritage, consists of various buildings from different epochs. Sustainable principles developed within the concept of smart, environmentally-friendly, and responsive cities requires energy optimization while minimizing energy amounts needed for systems of heating and cooling in buildings. Energy rehabilitation seems to become a strategically necessary and legally obligatory task in Serbia too. It means the implementation of various measures in term of the use of renewable energy resources and improvement of the thermal envelope of the already existing facilities. However, this type of interventions often reflects on the visual appearance of the building, changing its form, façade articulation and materialization. Respecting legally prescribed allowance, according to the degree of regime protection of cultural built heritage, the paper goal is to develop a model for the protection of the buildings in term of improvement of their energetic performances. The research aim is to identify the most optimal measures to be applied to increase energy efficiency depending on building's degree of protection, in Serbia, using multi-criteria decision-making methodology.

Integrated Sustainable Building Design

Today’s customers often require the vehicle manufacturer to document passenger compartment heating for specific test conditions. Without correct selection and sizing of the HVAC system for the passenger compartment, thermal comfort cannot be ensured. One of the aims that the manufacturers of modern vehicles have in mind is the development of new and optimization of the existing systems for achieving and maintaining thermal comfort in the passenger area. The selection of system components to achieve the required thermal comfort in the passenger compartment is the first step. The second step consists on the optimization of the selected thermal comfort control concept of the passenger compartment under various environmental conditions. For the computerized evaluation of thermal comfort at selected standing place, the 4 following measurement variables are used: air speed, humidity, air temperature and the temperature of the black ball. In addition to the prediction of percentage of unsatisfied persons during the heat up phase of the vehicle passenger compartment, the special thermal conditions in the vehicle are pointed out. Within the scope of the work the thermal comfort of the inhomogeneous is compared with the homogeneous environment. Using the operational and the equivalent temperature according to SAE J2234 the homogeneous environments are determined. The following external conditions are constant; incident-flow velocity of the vehicle, air temperature and humidity. The aim of the paper is to indicate a complexity of determining the thermal comfort conditions in passenger vehicles.

Influence of Wind Speed and Insolation on Heat Consumption in Buildings

This work introduces the aspects of the proper choice of the exploitation data connected with heat supplied to a building in order to estimate the influence of wind speed, insolation or level of cloudiness on energy consumption. The analyzed building had a traditional, central heating installation with vertical risers in each flat and convective radiators and supplied with the heating medium (80/60 °C). The exploitation data from one heating season were analyzed and the influence of the wind speed within the range below 3 m/s, 3÷6 m/s and above 6 m/s on the value of the heat power delivered to the building was presented. Different times of the day and night were taken into account and the attention to the accuracy of obtained results was paid.

Comparative Analysis of Electric Energy Consumption of Cascade System R134a/CO2 with Single Stage R404a and Two-Stage CO2 Installation

The paper analyzes electric energy consumption of three different refrigeration installations: cascade refrigeration system with R134a in the high temperature circuit and CO2 in the low temperature circuit, single stage refrigeration system operating with R404A and two-stage transcritical CO2 system. The indirect impact of the refrigeration system on global warming through electric energy consumption was examined. Thermodynamic cycles of these installations have been described and models have been developed to analyze the electric energy consumption required to drive the compressor as the largest consumer, for the cooling capacity of the evaporator 5,7 kW at evaporation temperature -30 °C for meteorological 2017, in the city of Belgrade. As a basis for comparative analysis, the existing cascade refrigeration system, which is located in the Laboratory for Thermal Science at the Faculty of Mechanical Engineering in Belgrade, was selected.

Climate Change and HVACR Systems

Indicators at a global level are presented: population in the world today and forecasts for developed and developing countries. The following diagrams are presented: world total primary energy consumption, global CO2 emissions from combustion since 1971, as well as cumulative CO2 emissions by regions since 1750. Facts for climate change are included (according to WMO and IPCC): increase in GHG concentrations, increase in air temperature, rise in sea level, etc. The consequences of global warming are listed: extreme rainfall and floods; high temperatures – heat waves, droughts, wildfires; huge damage to agriculture; harmful impacts on the environment, etc. The IPCC provides several scenarios for a global rise of air temperature up to 2100, for a global rise of sea level etc. The activities of the international community on climate change are organized through: IPCC, UNFCCC, Kyoto Protocol, Paris Agreement and continuous negotiations. The European Union (EU) is probably the most advanced in the battle against climate change. Some important strategies are outlined: by 2020, by 2030, and by 2050. Heating, air-conditioning and refrigeration systems (HVACR) are connected with energy consumption, which means they are a source of GHG emissions. The situation with HVACR systems is such that even in EU countries, the fossil fuels are dominant in the heating systems. Future solutions for HVACR systems are described. The first step is to increase the energy efficiency of buildings and HVACR equipment. The concept of "nearly zero-energy buildings" should be worked on. HVACR systems should be based on renewable energy sources (RES). The considered solutions include heat pumps, solar panels, thermal storage, district heating, combined heat and power, condensing boilers, reversible air conditioners, the concept of "smart" buildings, automation of HVACR systems with digital technology, etc. The political, economic and social aspects of climate change are analyzed. Capitalism society, market economy, profit, is the main reason for today's climate change situation. On the end, there is a discussion highlighting the need for urgent and major investment in RES and energy efficiency. For rich countries, this is really achievable. But developing countries, representing 83% of the world's population, need financial assistance, and this needs to be regulated through the Paris Agreement. Obstacles of a political nature are also possible (US and Paris Agreement).

HVAC System Enhancements for Improved IEQ and Energy Efficiency “Tropical Low Hanging Fruits”

The HVAC system needs to serve the primary role of conditioning the air before it is delivered to the occupied zones of a building. The increasing focus on human centricity in buildings and the unquestionable need to curb the dependency on fossil fuels due to climate change considerations has necessitated the HVAC design professionals to explore innovative means and strategies to enhance HVAC system performance for improved Indoor Environmental Quality (IEQ) and energy efficiency. This paper deals with simple cost effective interventions, comprising new strategies or technologies in the tropics, dubbed Tropical Low Hanging Fruits that could significantly improve the energy performance of the buildings whilst simultaneously enhancing IEQ. It is obvious that new technologies or strategies are easier to be implemented in new buildings. However, such technologies could be easily seen as viable options during the refurbishment phase of an existing building. In addition, several interventions become easily possible in the normal operation stage of a building. The various technologies/strategies presented in this paper are discussed in the context of both new and existing buildings.

Integrated Sustainable Building Design

The paper demonstrates combined labelling of buildings, which includes energy, indoor environmental and well-being aspects. The development of the proposed combined labelling is in progress in TripleA-reno project, which aim is to encourage the deep renovation of residential buildings.

Improving Solar Potential Map: Ditching Net-Metering, Embracing Demand Curve and Local Weather

The research expands the bottom-up approach to determine investment cost for self-sufficient Solar Plus systems. Existing solar maps usually utilize net-metering scheme and treat electricity grid as giant battery. However, with increased solar production, this might put an additional strain to the grid. In addition, to obtain national wide results, multiple weather patterns obtained from different meteorological stations were analyzed which also resulted in different demand curves. The scope of the research was therefore largely increased by calculating all available meteorological data in form of a typical year for Slovenia, which consist of 23 data points evenly spread all over Slovenia. However, those points vary quite a bit – some stations are positioned in the cities and towns, while others are located in small villages or places of interests (i.e., mountain resorts or airports). The points also vary in altitude (from few meters to over 2500 m) and cover different climate zones. The majority of Slovenia lies in continental zone (described with Dfb and Dfb by Köppen-Geiger climate classification) with cold winters and warm summers, with some subtropical climate at the coastal areas (Cfa and Cfb). Some mountain areas have tundra climate (ET). The presented research shows how to combine the existing data to calculate optimal Solar Plus instalment for self-sufficient buildings for each calculation point. The already validated simplified model was used for calculation of energy balance for the typical year which was later used for optimization of the results regarding costs. This includes the roof area for photovoltaic, optimal orientation of solar panels, the capacity of the battery storage and other influential parameters. The results clearly indicated the capability of each analyzed area for Solar Plus installation.

Solar Thermal Energy For Buildings – Current State and Perspectives

Almost 50% of final energy consumption in Europe and worldwide is addressed to thermal energy, which is significantly higher than energy needs for electricity for lighting and electrical appliances and for traffic. Building sector takes a significant share (about 40 %) in total primary energy consumption. Limited amounts of fossil fuels, their negative impact on environment, high and unstable prices and import dependency of fuels caused intensive growth and usage of solar thermal energy in the world. Solar heating and cooling are the most important solar sector worldwide, where installed solar system power is about 500 GWth and it is higher than PV system power and also the power of solar thermal plants. Today, according to the total installed collector capacity, China dominates on first place, then Europe, while United States comes right after, according to the SHC Agency data for 2016. With a district solar thermal plant in municipality Pančevo, Republic of Serbia also has its place at a world solar thermal map. This paper presents a review of different sizes, number, installed power and types of solar collectors and other characteristics of built solar thermal systems worldwide. Potential for possible usage of solar thermal system was identified and technological and other challenges and perspectives for future growth in the field of solar thermal energy were discussed.