In issue 7-8/2025

Słowa kluczowe: accreditation, laboratory, heating, strength testing

Streszczenie:
The scope of accreditation No. AB 414 of the Testing Laboratory (LB) of Veolia Energia Warszawa S.A., issued by the Polish Center for Accreditation, includes strength tests to evaluate: - quality and durability of materials used primarily in district heating and, less frequently, in refrigeration, construction or... sports, - finished products in terms of their compliance with requirements, standards and user expectations. At LB, strength testing includes a wide range of tests that allow us to evaluate the mechanical properties of materials and products. Strength tests include the following tests: static compression test - compressive strength at 10% strain, stress characteristics - compression strain and post-compression strain, bending test - bending strength, static tensile test - tensile strength, elongation at break and yield strength, and shear tests - shear strength, creep tests1 - deformation over time under constant load.

Słowa kluczowe: climate change, construction, phase change materials, heat flux, energy performance

Streszczenie:
Climate change is one of the most important challenges of modern construction, forcing buildings to adapt to increasing weather variability and extreme weather events. This article analyzes the impact of climate change on the energy demand of buildings and emphasizes the need to take into account current climate data when designing and retrofitting buildings. The article simulates the design heat load of a single-family building, demonstrating significant oversizing of heating systems when using current outdoor temperature design values. The results of the study indicate significant changes and fluctuations in the analyzed climatic parameters, which has a significant impact on the energy efficiency of the building, highlighting the need for adaptive mitigation strategies. The present research has long-term relevance in the context of developing strategies for changing the design norms of HVAC systems that take into account the indicated trends, and therefore changes in the formation of climatic zones. The key role of energy efficiency as the foundation of building energy resilience is also pointed out, emphasizing the integration of insulation, renewable energy sources and heat storage technologies, including passive systems such as Trombe walls and phase change materials (PCM). In light of projected climate trends, a comprehensive approach to building design is essential to ensure occupant comfort and sustainable energy consumption.

Słowa kluczowe: domestic hot water, nursing homes, water consumption, energy efficiency, heat transformers, CO2 reduction

Streszczenie:
In assisted living facilities, the consumption of domestic hot water (DHW) is much higher than in typical residential buildings, which translates into high heat demand. The paper presents an analysis of the potential for reducing primary energy consumption for hot water preparation and CO2 emissions associated with hot water preparation, conducted for a real facility. The case study includes a comparison of a legacy system based solely on an oil-fired boiler plant with a hybrid system currently in operation, combining an oil-fired boiler plant with an air-to-water heat transformer. The analysis showed significant energy savings and a reduction in CO2 emissions after implementing the new solution.

Słowa kluczowe: radiation heat transfer, equivalent heat transfer coefficient, heat loss, heat gain, linearization of the Stefan-Boltzmann equation

Streszczenie:
In the construction industry, in issues related to the thermal protection of buildings, great importance is attached to the value of the heat transfer coefficient, considering it sufficient to include in its value the effects of heat conduction and convection. Radiative heat transfer is often overlooked. In most cases, it is justified here, since the purpose of the calculation is to evaluate the thermal protection effects of buildings in winter conditions, where radiative heat transfer is actually of marginal importance. The situation changes during the summer, when the outer parts of the partitions can be heavily insolated and can heat up to high temperatures. Elevated surface temperatures of exterior walls can also be observed in winter, on surfaces exposed to the sun. This paper analyzes the effect of radiant heat transfer on the determination of the equivalent heat transfer coefficient and heat loss and gain through the building envelope. The results of the modeling carried out indicate that radiation heat transfer from the interior of the building and solar radiation affect the calculation results. Using the author's mathematical model, the temperature of the exterior wall was calculated. This temperature is often significantly higher than the ambient temperature, and the equivalent heat transfer coefficient is also higher. The greatest effect is seen with heat gains in the summer season. This leads us to believe that taking into account radiative heat transfer can be important in the heating season, but it is particularly important in summer and affects the determination of the cooling capacity of buildings.

Słowa kluczowe: Thermal modernization, CO2 emissions, heating power, historic buildings

Streszczenie:
This article is related to the European Union's policy on thermal modernization of buildings. The heating power requirement of a two-family semi-detached house before and after thermal insulation was analyzed. The demand for the required heating power of the building at the temperature of -20°C required for the III climatic zone in Poland, where the building is located, was determined. For this purpose, a simulation model was built in SolidWorks 2020 using the Flow Simulation module that allows analysis of heat transfer through building elements. Zones of increased heat transfer were indicated, which is related to the location of heat sources that require additional insulation. The presented method is also a solution for historic buildings that have conservation restrictions.

Słowa kluczowe: thermomodernization, energy saving, heating installation, radiators, heat loss

Streszczenie:
The article analyzes the possibility of using the existing heating system in a building or apartment after insulating the building envelope to the currently required insulation conditions of the building envelope, while replacing the heat source with a new more efficient and environmentally friendly source in the form of a heat pump. Changes in the thermal loads of sample rooms were carried out. The degree of adjustment of the changed thermal capacities of the existing radiators to the new heat losses from the rooms after insulating the cooling partitions while lowering the design temperature in the central heating system was checked. The results show that in most heated rooms it is possible to use existing central heating systems with reduced heat losses. Simultaneous lowering of the temperature parameters of the medium allows the use of heat pumps under these conditions.

Słowa kluczowe: drying, heat pump, heat storage, photovoltaic-thermal system, energy efficiency

Streszczenie:
This article presents an overview of solar-assisted heat pump (SAHP) technologies that are used in drying processes. The current state of development of SAHP systems is discussed, taking into account four main directions for improving their efficiency: integration with photovoltaic-thermal (PVT) systems, optimization of collector design, heat storage and the use of an improved ejector. Analysis of the effectiveness of different types of SAHP systems in the drying process shows their significant potential in this area. In addition, the use of PVT technology and optimization of collector design increase the efficiency of solar energy utilization. Heat storage allows for even heat utilization, and the improved ejector improves system efficiency by recovering refrigerant expansion work.

Słowa kluczowe: visual comfort, visual performance, integrative lighting, lighting requirements, lighting design criteria, visual environments

Streszczenie:
Indoor environmental quality (IEQ) includes, among other things, visual comfort and well-being, which is influenced by, among other things, adequate lighting. Indoor lighting, resulting from daylight, electric light or a combination of both, affects not only the visual performance and comfort of occupants, but also their mood, alertness and health. The latter are defined as the "non-visual effects" or "non-visual effects" of lighting. A few years ago, the term "human-centered lighting" (HCL) was popularized, even commercially, to include these effects in general, and more recently, the CIE (International Commission on Illumination) introduced the term "integrative lighting" to define "lighting that integrates both visual and non-visual effects and provides physiological and/or psychological benefits to people." Although HCL is still used (and sometimes abused), integrative lighting is preferred. Nowadays, for non-visual effects related to the impact of light on circadian rhythms, the CIE has proposed a metric [1], and some requirements have already been proposed in standards [2], as agreed upon by the scientific community [3].

Słowa kluczowe: indoor air quality (IAQ), ventilation, standards

Streszczenie:
Indoor air quality standardization mainly focuses on health requirements and ventilation requirements. Health requirements are set by the WHO and often referenced in IAQ standards. Currently, the most important European standard for indoor air quality is EN 16798-1/2. This standard was developed under CEN TC156 Ventilation and is currently under revision. A similar standard, ISO 17772-1/2, was developed in parallel by ISO. This standard also covers requirements for thermal comfort, acoustics and lighting. In this article, we will focus on the parts relating to indoor air quality. There are hundreds of substances in indoor air that can affect occupant health and perceptions of air quality, so standards often specify a certain ventilation factor as a criterion for indoor air quality. The article explains the use of the standard and gives examples of criteria using both recommended ventilation rates and criteria for specific substances.