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Continual two-year measurements of daylight illuminance were performed in order to evaluate the daylighting of a model room. The key research idea was to study room orientation and its effect on daylight availability by using real measurements from a physical scale model. Firstly, differences between the illuminance in the north- and south-oriented rooms were compared. Secondly, a characteristic annual profile of the external horizontal illuminance data was determined. Finally, the median external diffuse illuminance data from measurements were compared with values based on the values recommended in the standard. The goal of the research was focused on the evaluation of a regional daylight climate model applicable for daylight evaluations. The results of the daylight illuminance measurements showed the importance of climatic daylight data for indoor daylighting in building design performance. [ABSTRACT FROM AUTHOR]

The sunlight exposure represents one of key parameters of indoor climate comfort. The evaluation of sunlight access into buildings is based on a methodology of European standard EN 17037. The methodology is focused on specification of an insolation time which would comply with requirements for the sunlight expo sure of permanently occupied spaces like houses and residential buildings as well as schools or hospitals. The sunlight exposure evaluation is recommended to be between 1st February and 21st March. The specific date from the interval can be selected for individual evaluations. This is a relatively long period of days in which the insolation could vary meaningfully. The aim of this study is to evaluate how the sunlight exposure might be changed in the recommended standard period in dependence on the geographic locality and climatic conditions in the Central Europe region. It depends on the sunlight time and specific design situations as well as shading obstructions. The review of the sunlight exposure is determined. The review results can perform information about design possibilities for the sunlight exposure in real buildings in the given climatic locality. [ABSTRACT FROM AUTHOR]

Light pipes transmit daylight into building interiors. Their installation into thermally insulated roofs of low energy buildings can be a problem because of thermal bridges and condensation problems. This article is focused on a CFD simulation thermal analysis that includes four variations of light pipes with a segment of a flat roof. Common light pipes with a hollow light guiding tube were compared to special light pipes containing an additional glass unit located inside the tube. The additional glass units increase thermal resistance and reduce condensation risks of the light guiding systems. The light pipes were compared in two different simulation models run in ANSYS Fluent software and the CalA program. Temperature profiles and air flow patterns of the cross sectional profiles of the light pipes served to determine the total heat transmittance and heat losses of the studied light pipes installed in a segment of a thermally insulated flat roof. The paper compares simplified 2D rotational–symmetrical numerical model based on the thermal diffusion equation with the complex 3D CFD numerical simulation. The results confirm that the simplified 2D numerical model is suitable for the thermal evaluation of the light pipes containing an additional glass unit, too. The additional glass unit with the triple glass improves thermal resistance up to 88% in case of light pipe with diameter 600 mm and reduces optical transmittance to 28%. [ABSTRACT FROM AUTHOR]

Tubular light guides are applicable for daylighting of windowless areas in buildings. Despite their many positive indoor climate aspects they can also present some problems with heat losses and condensation. A computer CFD model focused on the evaluation of temperature distribution and air flow inside tubular light guides of different dimensions was studied. The physical model of the tested light guides of lengths more than 0.60 m proves shows that Rayleigh numbers are adequate for a turbulent air flow. The turbulent model was applied despite the small heat flux differences between the turbulent and laminar model. The CFD simulations resulted into conclusions that the growing ratio of length/diameter increases the heat transmission loss/linear transmittance as much as by 50 percent. Tubular light guides of smaller diameters have lower heat transmission losses compared to the wider ones of the same lengths with the same outdoor temperature being taken into account. The simulation results confirmed the thermal bridge effect of the tubular light guide tube inside the insulated flat roof details. The thermal transmittance of the studied light guides in the whole roof area was substituted with the point thermal bridges. This substitution gives possibility for simple thermal evaluation of the tubular light pipes in roof constructions. [ABSTRACT FROM AUTHOR]

Indoor climate comfort is important for school buildings. Nowadays, this is a topical problem, especially in renovated buildings. Poorly ventilated school classrooms create improper conditions for classrooms. A post-occupancy study was performed in a school building in temperate climatic conditions. The evaluation was based on the results of long-term monitoring of the natural ventilation strategy and measurements of the carbon dioxide concentration in the school classroom's indoor environment. The monitoring was carried out in an old school building that was constructed in the 1970s and compared to testing carried out in the same school classroom after the building was renovated in 2016. Surprisingly, the renovated classroom had a significantly higher concentration of CO2. It was found that this was due to the regulation of the heating system and the new airtight windows. The occupants of the renovated classroom have a maintained thermal comfort, but natural ventilation is rather neglected. A controlled ventilation strategy and installation of heat recovery units are recommended to solve these problems with the classroom's indoor environment. Microbiological testing of the surfaces in school classrooms also shows the importance of fresh air and solar radiation access for indoor comfort. [ABSTRACT FROM AUTHOR]

Existing building stock represents potential for energy saving renovations. Energy savings and indoor climate comfort are key demands for sustainable building refurbishment. Especially in schools, indoor comfort is an extremely important issue. A case study of energy consumption in selected school buildings in temperate climatic conditions of Central Europe region was performed. The studied buildings are representatives of various school premises constructed throughout the last century. The evaluation was based on data analysis of energy audits. The goal was aimed at assessment of the school building envelopes and their influence on energy consumption. One of the studied schools was selected for detailed evaluation. The school classroom was monitored for indoor thermal and visual environments. The monitoring was performed to compare the current state and renovation scenarios. Results of the evaluation show that the school buildings are highly inefficient even if renovated. Indoor climate in classrooms is largely influenced by windows. Solar gains affect interior thermal stability and daylighting. Thermal insulation quality of building envelopes and efficient solar shading systems appear to be fundamental tasks of school renovation strategies. [ABSTRACT FROM AUTHOR]

Currently, there is an increasing need for reliable mechanisms for automatically detecting and localizing people—from performing a people-flow analysis in museums and controlling smart homes to guarding hazardous areas like railway platforms. A method for detecting people using FLIR Lepton 3.5 thermal cameras and Raspberry Pi 3B+ computers was developed. The method creates a control and capture library for the Lepton 3.5 and a new person-detection technique that uses the state-of-the-art YOLO (You Only Look Once) real-time object detector based on deep neural networks. A thermal unit with an automated configuration using Ansible encapsulated in a custom 3D-printed enclosure was used. The unit has applications in simple thermal detection based on the modeling of complex scenes with polygonal boundaries and multiple thermal camera monitoring. An easily deployable person-detection and -localization system based on thermal imaging that supports multiple cameras and can serve as an input for other systems that take actions by knowing the positions of people in monitored environments was created. The thermal detection system was tested on a people-flow analysis performed in the Czech National Museum in Prague. The contribution of the presented method is the development of a small and simple detection system that is easily mountable with wide indoor as well as outdoor applications. The novelty of the system is in the utilization of the YOLO model for thermal data. [ABSTRACT FROM AUTHOR]

Abstract: Tubular light guides represent a convenient concept for illumination of windowless parts of buildings by natural light. The transmittance of this optical device generally varies with geometrical characteristics as diameter and length and also with its properties. A high light transmittance of the roof dome and diffuser as well as high quality of the inner reflective surface facing of the light guiding central duct are required. External daylight conditions such as sky cloudiness or sky luminance distribution have undoubtedly a vital influence on the tubular light guide efficiency. A daylight computer simulation study focused on an evaluation of the tube light efficiency is presented in the article. The efficiencies of straight tubular light guides are computed for the standard overcast and clear sky luminance distributions. The results obtained can be useful for predetermination of a luminous flux emanating a light guide, for evaluation of indoor daylighting, and for elaboration of various daylight strategies. [Copyright &y& Elsevier]

A comprehensive study of straight light pipe efficiency and illuminance distribution below ceiling level is performed using HOLIGILM tool. The recommendations for light guide systems can be made for different latitudes and sky luminance patterns using the data computed here. The computational results show that the light pipe transmittance is a monotonic function of solar altitude, except for low-sun angles. Redistribution of photons at the light pipe base can be characterized by a scalar value called “asymmetry parameter”, g . A use of g is an efficient attempt to the classification of a large number of luminous intensity distributions. The minimum value of g is at low solar elevations (between 10° and 30°) because of balanced contribution of diffuse light of a sky and the direct sunbeams. The low values of g indicate the redistribution of light is more uniform. Luminous intensity solid determined by means of HOLIGILM tool is used to compute illuminance distribution at a working plane. The peak intensity and intensity gradient of a bright ring projected onto a working plane can be used to characterize the optical properties of different light pipes in different climatic zones. [ABSTRACT FROM AUTHOR]

The SMART City concept is primarily associated with the European Union’s goals and strategies in the upcoming period and it is introduced in detail in the strategic EU document Europe 2020. The article describes the SMART Region concept being implemented in the Czech Republic environment. It introduces a pilot project in the city of Brno district – Nový Lískovec in the Czech Republic and its transformation from a prefabricated housing estate from the 1980s through energy efficient renovation of the entire city district towards a SMART City concept vision. The energy refurbishment concepts and strategies applied to the city district together with real post occupancy operation data of a reference prefabricated block of flats are summarized. The current research activities related to the indoor climate in the prefabricated block of flats and energy efficiency of the whole city district region are further specified. The future research tasks, municipality visions, and targets to become a SMART Region city district are discussed. [ABSTRACT FROM AUTHOR]