In the interest of environmental protection, attention should be paid to improving energy efficiency, through the use of appropriate insulations. They can be used in the construction industry, for plastic window frames, and the thermal insulation of buildings. It is also possible to use these materials in the electronics industry, for hermetic casings of devices, in the aviation industry, as well as in the food industry, as collective packaging for frozen food. The technology of using additive 3D printing to create prototype insulating materials made of plastic is proposed in this article. Multi-layer materials, with quadrangle, hexagonal, and triangle closures were designed and printed. A mathematical model was developed, and then experimentally verified. Quadrangle and hexagonal structures were shown to be useful, and triangle structures to be of little use. The optimal size of closure was determined to be 10 mm, with no convection, and 6 mm, with possible convection. The lowest thermal conductivity of the insulation was 0.0591 W/(m·K) for 10 mm single-layer quadrangle and hexagonal closures with an insulation density of 180 kg/m³.

Theoretical investigations of the ejector refrigeration system using hydrofluoroolefins (HFOs) and hydrochlorofluoroolefin (HCFO) refrigerants are presented and discussed. A comparative study for eight olefins and R134a as the reference fluid was made on the basis of a one-dimensional model. To facilitate and extend the possibility of comparing our results, three different levels of evaporation and condensation temperature were adopted. The generator temperature for each refrigerant was changed in the range from 60 °C to the critical temperature for a given substance. The performed analysis shown that hydrofluoroolefins obtain a high efficiency of the ejector system at low primary vapor temperatures. For the three analyzed sets of evaporation and condensation temperatures (t_e and t_c equal to 0 °C/25 °C, 6 °C/30 °C, and 9 °C/40 °C) the maximum Coefficient of Performance (COP) was 0.35, 0.365, and 0.22, respectively. The best performance was received for HFO-1243zf and HFO-1234ze(E). However, they do not allow operation in a wide range of generator temperatures, and, therefore, it is necessary to correctly select and control the operating parameters of the ejector.

A building’s facade is its main interface with the external environment, as it controls almost all energy flows in the building—losses and gains. In this context, the most recent invention of adaptive façades allows for the introduction of an optimized system for both daylight management and electrical energy production. The authors of the presented paper propose a novel adaptive façade system that is equipped with vertical shading fins of 1 × 4 m that are covered with PV panels. The fins are kinetic and rotate around a vertical axis in order to optimize solar irradiation for producing electricity. The presented adaptive façade is analyzed in two stages. Firstly, the number of vertical shading fins is optimized in the context of useful daylight illuminance (UDI) and daylight glare probability (DGP) using Radiance-cored software. Next, two scenarios of PV installation are verified for fixed and the Sun-tracking solution. The results show that the Sun-tracking system is more efficient than the fixed one, but electricity production is only increased by 3.21%. The reason for this is the fact that—while following the Sun’s azimuth position—fins shade each other and reduce the effective area of the adjacent PV panels. Based on this, the authors conclude that the Sun-tracking system might be justified due to its protective or decorative function and not because of its improved effectiveness in generating electrical energy.

This article presents the results of a study into a packed bed filled with ceramic bricks. The designed storage installation is supposed to become part of a heating system installed in a single-family house and eventually to be integrated with a concentrated solar collector adapted to climate conditions in Poland. The system’s working medium is air. The investigated temperature ranges and air volume flow rates in the ceramic bed were dictated by the planned integration with a solar air heater. Designing a packed bed of sufficient parameters first required a mathematical model to be constructed and heat exchange to be analyzed, since heat accumulation is a complex process influenced by a number of material properties. The cases discussed in the literature are based on differing assumptions and different formulas are used in calculations. This article offers a comparison of various mathematical models and of system operating parameters obtained from these models. The primary focus is on the Nusselt number. Furthermore, in the article, the thermo-hydraulic efficiency of the investigated packed bed is presented. This part is based on a relationship used in solar air collectors with internal storage.

When designing a year-round home heating system that uses only solar radiation energy, the cooperation of an architect and an HVAC (heating, ventilation, and air conditioning) designer is necessary. These systems occupy a large area in relation to a building’s floor surface, especially when they are located in a climate like Central Europe or colder. The aim of the article was to create a balanced integration process by implementing the subsequent steps that are necessary to integrate a solar heating system within a building. In the first stage, a solar collector and a heat accumulator were selected. The innovation of the system involves the use of a solar concentrating collector as an air heater. Assessment criteria were then proposed in order to show the influence of the location of the solar heating system on the building’s architecture, functionality, and energy balance, while at the same time assuming its passive standard. System integrations concerning both an existing and new building were analyzed. The system’s basic components were selected for the three chosen solutions, taking into account the possibility of using heat losses resulting from the location of the installation.