The paper presents the possibility of management the fan performance in dependence on CO₂ concentration. A mathematical calculation is made from the prediction of the electric energy consumption for a variant control algorithm. The most advantageous algorithm is programmed into the actual fan control system, and its power consumption is shown in graph. Finally, the saving of the adaptive control is compared to the classical control over time. To program the control algorithm, the CO₂ mass balance equation is used. The equation depends on the input values, namely the number of CO₂ sources, the room volume and the supply air. Due to the infinitely variable of fan control, it is possible to adjust the power setting depending on the expected development of the logarithmic rise of CO₂ concentration in the room. This prediction is programmed with the Visual Basic code and program code can be used to the Arduino control unit, which controls the EC fan power with a 0-10 V signal. Although significant savings over a short period of time can not be expected, the ventilation system where the fan runs for a significant part of the year will be substantial. Therefore, the result will be presented by graphical diagrams of different ways of controlling the fan per year of operation.

This case study presents a comparative analysis of real-world operation of two residential domestic hot water (DHW) preparation methods both connected to their own air-to-water heat pump (HP) located in Central Europe. One system employs a conventional configuration with separate tanks and an internal heating coil (HP-B), while the other features a compact tank-in-tank setup where DHW is heated via an integrated buffer tank (HP-A). Both systems were monitored under real operational conditions, with seasonal and annual coefficients of performance (COP, SCOP) calculated to evaluate efficiency. In the absence of complete thermal output data for one system, a reconstruction method based on the other’s performance and known heat losses was applied. The findings confirm that DHW system design significantly affects seasonal efficiency, particularly during summer operation when heating DHW dominates the energy load. The energy cost savings on heating during summer months could reach 44%. The tank-in-tank system showed higher electrical consumption and lower SCOP due to internal heat transfer dynamics and dual-function operation. The study further shows associated energy and cost differences and demonstrates a practical approach to comparing real-world systems offering insights for design optimisation and operational strategy. The authors of the article used the results of their research and experience from implementations as very effective feedback for further research and development. The novelty and uniqueness of the article lie in the energy comparison of two different connections of the hot water and heating water storage tanks with heat source systems using an “air-to-water” heat pump. The benefit of the solution in question is evident from the technical and economic evaluation.

In this study, we evaluate the qualitative thermal performance of a groundwater borehole by monitoring the temperature at the primary (borehole) and secondary (heat pump) sides of a domestic heat pump over three heating seasons between 2010 and 2013. Based on early results, the borehole was extended during the monitoring period in order to increase performance. Our results suggest that the temperature parameters of a borehole do not remain constant and that a borehole’s properties can change significantly over time if the borehole substrate temperature is not given time to regenerate.

The paper analyzes the microbial constituents residing in buildings with more people, such as basic school or office spaces. The aim is to determine whether these areas with similar equipment and similar cleaning regime have similar parameters of microbial environment. Within the quantitative analysis we have carried out the collection of microbial particles dispersed in the air and deposited on floors, furniture and walls inequalities. It was found that the internal environment of buildings with natural ventilation is significantly on the condition of ambient air. In the environment of greater occupancy there are more bacteria than fungi. Rooms in the same building, but not directly neighbouring, have an independent environment.

The paper describes the importance of monitoring the dust in the atmosphere of human life. It deals with the issue of dust in air ducts, approaching the methods that can be used to detect the amount of dust. For conditions for buildings in the Czech Republic there is created the methodology of quantitative and qualitative evaluation of dust sediment for the needs of HVAC and other building surfaces. The scale for visual evaluation was created and it has been elaborated the assessment of kind of particles contained in dust.

Ventilated façade systems are being increasingly used in energy-efficient building envelopes due to their configurational flexibility and potential to reduce thermal bridging. This study focuses on the experimental evaluation of anchoring components used in such systems, specifically examining the effect of various thermal insulation pads and internal inserts on the system’s mechanical, thermal, and fire performance. A series of laboratory tests was carried out to assess the static behavior of aluminum brackets under both tensile (suction wind load) and compressive (pressure wind load) forces. The results demonstrate that the use of thermal pads and inserts does not lead to any significant degradation of the mechanical capacity of the anchoring brackets, confirming their structural reliability. Additional thermal testing revealed that the use of insulating materials significantly reduces heat transfer through the brackets. Fire resistance tests were conducted to compare the performance of different types of insulation pads under elevated temperatures. The findings indicate that the choice of pad material substantially influences both fire integrity and thermal performance. This study confirms the potential of incorporating optimized insulating pads and inserts into façade brackets to enhance the thermal and fire performance of ventilated façades without compromising their structural behavior.