The paper shows alternative refrigerant mixtures for R134a that can be used in heat pump air-water systems with ecological alternatives R1234yf, R452A and R513A. In the article it is shown the calculation of COP with Chemours Refrigerant Expert software for single stage heat pump cycle. As a result of the new legislative strategy at international level regarding the refrigerants, in the following years must be find ecological alternatives in terms of global warming potential (GWP) in according with Fgas Regulation

As quality becomes a more and more weighty concept in the field of construction, as a general client expectation on the one hand, as well as a constructor/developer commitment and claim, on the other hand, we have found that there is no such thing as a specific definition of it. As such, in the present paper we have sought to put together a clearer and more practical perspective on what ‘quality’ actually means – or should mean – in construction projects, in addition to coming up with recommendations for establishing and meeting such requirements throughout the duration of a project

The increasing need for energy-efficient buildings has led to the development of smart solutions that integrate cutting-edge technologies, such as artificial intelligence (AI), into building services systems. This paper explores the role of AI in improving building energy performance, highlighting the benefits and challenges of integrating AI into building systems. The paper presents a review of relevant literature on AI-based building energy management systems and provides a case study of some AI-based solutions for building services systems management in an administrative building. The results show that AI can significantly improve building energy performance. However, successful implementation of AI-based solutions requires careful consideration of various factors, such as data quality, system complexity, and user acceptance

The paper presents challenges to be considered by engineers and by owners, managers and occupants in the perspective of the global warming, requiring measures for replacing the fossil fuel sources with renewable ones, as used by HVAC equipment. Air Source Heat Pumps, ASHP and Ground Source Heat Pumps GSHP are issues considered for the transition to “A Clean Planet for All” as a decarbonization path of the building sector. Retrofitting the envelope and using heat pumps is aimed for a greenhouse gas GHG mitigation in order to limit the climate change. Reaching a net reduction in CO2 emission involve a series of stages- envelope insulation, replacing the boiler with a heat pump, new, oversized heat emitters (and pipes), adapted circulation pumps, predictive control systems, and possible new network concepts

Two road corridors in Ibadan City where the use of tricycles is prominent namely Mokola to Agodi Prison Gate Road (MAR) and Challenge to Orita Challenge Road (COR) were identified. Traffic volume data were collected from Monday to Friday during the peak periods, likewise the socio-economic characteristics of tricycle operators using questionnaires. Traffic volume counts revealed that the percentage of tricycles compared to other transportation modes ranged between 9.54% and 20.08% along MAR and between 13.27% and 19.61% along COR. The socio-economic characteristics data showed that 98.5% of the operators were male, their ages ranged between 18 and 60 years and 26.5% had a monthly income of more than N40,000. Tricycle had the second highest arrival rates along MAR and COR of 6.17 and 7.91 respectively

This study investigates the airborne transmission risk of infectious diseases in a classroom setting, aiming to develop a comprehensive risk measurement model. The research employs a combination of computational fluid dynamics simulations, viral load measurements, and epidemiological data to analyze airflow patterns, ventilation efficiency, and viral dispersion in classrooms. Real-time monitoring of air quality, temperature, and humidity is integrated to establish a risk assessment framework. The findings reveal the significance of proper ventilation and strategic classroom layout in mitigating airborne disease transmission. This research offers practical insights for educational institutions to implement informed strategies to minimize airborne risks, ensuring a safer learning environment

Applying the method of reinforcing cement-concrete with chicken feather fibers was extended to fly ash-based geopolymer concrete. Four manufacturing recipes were used, in which the fiber amount was modified between 6-9 kg?m-3 and NaOH molarity in the alkaline activator varied from 8M to 10M. Curing process of the fresh geopolymer was performed with 80 ºC-steam for 24 hours and then at room temperature for 36 hours. The specimen mechano-physical characterization was made after 7 and 28 days and the results showed obtaining high values of compression strength of 45.1 and 47.8 MPa and flexural strength of 14.5 and 15.6 MPa

The increase in global temperature and the current energy context have brought the district heating system in Timi?oara (partialy renovated) to the brink of collapse. Therefore, major investments and orientation towards the integration of renewable energy sources (RES) are required. The article analyzes, by exemplifying a case study, the integration of photovoltaic technologies at a heat point that supplies the buildings of the Faculty of Construction (CT) in Timi?oara. The study was carried out with the help of Polysun software. The results obtained indicate a reduction in thermal and elctrical energy costs of 38.51% by installing a number of 1095 photovoltaic (PV) panels on the roof of 4 building bodies (ASPC, Deposit, CT and Metal)

3D city models are tridimensional representations of cities, focused on buildings that can be used as a base for numerous analyses such as heat demand estimation, solar radiation estimation, visibility analyses, noise analyses, or for urban and emergency situations planning. Geospatial data used to develop such models can be acquired through different methods, one of them being using a LiDAR point cloud. Virtual Reality can be a useful tool in exploring these 3D city models and may offer a better understanding of the different situations that need to be analyzed. The aim of this paper is to investigate the possibilities of exploring the 3D model of Baia Mare city in a VR environment

In modernizing energy systems, European countries are focusing on a smart energy system, and one of the goals of which is the rational use of energy resources and the reduction of negative environmental impact. The concept of the low temperature district heating in the smart energy system is one of opportunities to decrease loses and waste of energy and to implement a systemic approach to the energy use. A roll-out could begin selectively, based on experimental project activities in the near future, new construction will be used to develop the business infrastructure necessary for later, more widespread deployment. The aim of the research is to summarize challenges and benefits in the implementing of the low temperature district heating concept in the smart energy system. The object of the research: challenges and benefits in the implementing of the low temperature district heating concept. The objectives: to systemise the smart energy approach in sustainable future; to analyse the concept of the low temperature district heating in a smart energy system; to characterise risks and opportunities of the low temperature district heating concept. There were used these scientific methods: induction, systemic analysis, comparative analysis and synthesis of partial scientific knowledge. Analysis of various scientific articles and studies shows energy conservation, increased use of renewable energies, smart grids to promote renewable energy utilization, cleaner technologies, multigeneration, and efficient storage of energy carriers are necessary conditions for the transition to smart energy systems for a sustainable future. The low temperature district heating concept is associated with some forms of risk, but the dissemination of experience and on modern digital technologies based management can help to achieve ecological benefits although reduced CO2 emissions, minimize heat loses and waste of energy, to reduce costs of energy production and to improve the image of heating companies

In the light of the increasing exploitation of natural resources, a rigorous approach and an effective identification of practical solutions needed to ensure the conservation of the environment is required, given the crucial importance of this issue. This scientific work explores an innovative method of treatment and improvement of landfill gas produced from municipal and similar wastes, for a carefully selected and thoroughly studied landfill, in order to obtain a sustainable alternative fuel that can be used in natural gas installations.The method analyzed in this study is called high-pressure water scrubbing, which allow the production of biomethane. Additionally, using the mathematical model LandGEM, the energy potential and gas generation rate was determined, for a selected landfill located in Alba Iulia, Romania country. This article also provides a review of technology that uses the high-pressure water scrubber for the integration of improved landfill gas into the mobile cylinder. Through this investigation, the landfill in Alba Iulia, Alba administrative territorial unit, Romania, can be considered as an energetic resourse who can be used through a sustainable potential solution for protecting current natural resources.

In an existing office building, integrating air-to-water heat pumps into a district heating system can bring multiple benefits in terms of energy efficiency and thermal comfort. The article deals with the implementation solution for the efficiency of district heating systems, exemplified by a case study related to an existing office building. The study was carried out following the multiple breakdowns that occurred in the thermal energy distribution system from the district heating company, as well as the interruption of thermal energy for long periods of time

In the current context regarding energy sources’ problems, it is estimated that photovoltaic panels will produce a high percentage of waste that will put pressure on the environment. Thus, the study focuses on recycling them by incorporating them into mortars by four new mortar recipes (R1, R2, R3 and R4) that integrate photovoltaic panels’ dust (PVd) and pieces of photovoltaic panels (PVp), replacing the sand with PVd and PVp (1/3 to 100% of the total amount). All samples were subjected tensile bending and compression tests and were compared with the control sample (R0). As a result of the experimental research, a change in the apparent density of the proposed samples was found, and from the point of view of the tensile strength, R2 and R4 were found similar to sample R0 in both tests. The obtained results show that used photovoltaic panels can constitute raw material for the creation of new construction materials