Usage of the Wind Energy for Heating of the Energy- Efficient Buildings: Analysis of Possibilities

The paper analyzes and compares the energy demand for heating purpose of new buildings with different energy perfomance rates. Article studies global renewable energy sources innovations, statistics and scientific and engineering experience to ensure the building's thermal energy needs, produced by transforming wind energy.Distribution of the potential of one renewable source – wind energy – during the year is similar to the energy necessary for the building heating, thus production of the heating energy from mechanic energy of the wind is chosen for further scientific investigations. Wind power plant, generating 2 kW of heat power, installed as a heating source for the analysed individual house, can cover from 40 to 76% annual heat needs of the building, subject to its energy-efficiency class, respectively 1.5 kW – from 31 to 68%, 1 kW – from 22 to 53%

Analysis of the impact of high-space building heating system solutions on nuilding energy efficiency

The existence of stratification in high-ceiling buildings is real, but not visible or easy noticeable by humans. For field measurements, the Prayer House – The Kaunas Basilica of the Resurrection of Christ, located in Kaunas, Lithuania, was chosen, in which the temperature distribution at different heights (6 m, 8 m, 10 m, 12 m, 14 m, 16 m and 18 m) during the heating season was observed. The Basilica had radiant heaters installed at 5 m height. According to the plan of the Prayer House, CFD model was created, and the temperature distribution of the different heating (radiant heating and floor heating) systems were compared. The IDA-ICE modelling of energy consumption was conducted using the CFD results as a basis, and the economic analysis was performed based on the obtained results. The study confirmed the existence of stratification in high-ceiling buildings. Keywords: stratification, high ceiling buildings, radiant heaters, energy efficiency, FloVent, IDA-ICE, CFD

Field Measurements and Numerical Simulation for the Definition of the Thermal Stratification and Ventilation Performance in a Mechanically Ventilated Sports Hall

Sports halls must meet strict requirements for energy and indoor air quality (IAQ); therefore, there is a great challenge in the design of the heating, ventilation, and air conditioning (HVAC) systems of such buildings. IAQ in sports halls may be affected by thermal stratification, pollutants from different sources, the maintenance of building, and the HVAC system of the building, as well as by the activities performed inside the building. The aim of this study is to investigate thermal stratification conditions in accordance with the performance of the HVAC systems in the basketball training hall of Žalgirio Arena, Kaunas in Lithuania. Field measurements including temperature, relative humidity, and CO2 concentration were implemented between January and February in 2017. The temperature and relative humidity were measured at different heights (0.1, 1.7, 2.5, 3.9, 5.4, and 6.9 m) and at five different locations in the arena. Experimental results show that mixing the ventilation application together with air heating results in higher temperatures in the occupied zone than in the case of air heating without ventilation. Computational fluid dynamics (CFD) simulations revealed that using the same heating output as for warm air heating and underfloor heating, combined with mechanical mixing or displacement ventilation, ensures higher temperatures in the occupied zone, creating a potential for energy saving. An increase of air temperature was noticed from 3.9 m upwards. Since CO2 concentration near the ceiling was permissible, the study concluded that it is possible to recycle the air from the mentioned zone and use it again by mixing with the air of lower layers, thus saving energy for air heating