scholarly journals Dew point temperature analyses in ground floor residential room with existing thermal bridge

2019 ◽  
Vol 112 ◽  
pp. 01017 ◽  
Author(s):  
Martin Ivanov
Keyword(s):  
Field Measurements ◽  
Building Design ◽  
Energy Performance ◽  
Building Envelope ◽  
Dew Point ◽  
Point Temperature ◽  
Ground Floor ◽  
Dew Point Temperature ◽  
Thermal Bridge ◽  
Infrared Thermal Images

The presented study reveals a dew point temperature analyses in ground floor residential room with existing thermal bridge. The dew point temperature is analysed, based on field measurements of indoor air temperature and relative humidity in the residential room, without organized occupants’ behaviour. Furthermore, the dew point temperature is cross-analysed with existing thermal bridge propagation in one of the outer walls of the room, via infrared thermal images. The results represent a valuable indicator for moisture accumulation over the thermal bridge zone, as well as an indicator for future mold growth and other humidity related problems. In the building design practice, the “thermal bridge” is defined as a distant zone, where construction elements have higher thermal conductivity, compared with the rest of the building envelope. These thermal bridges mostly affect the energy performance of the buildings, because of the higher heat losses from inside towards outside. But even more important, moisture build-up and considerable humidity related problems in the occupied areas are probable, due to the decreased surface temperature over the affected thermal zones.

scholarly journals Instantaneous field measurements of thermal bridge parameters in ground floor residential room

2019 ◽  
Vol 112 ◽  
pp. 01016 ◽  
Author(s):  
Martin Ivanov
Keyword(s):  
Energy Demand ◽  
Field Measurements ◽  
Building Design ◽  
Building Envelope ◽  
Ground Floor ◽  
Thermal Bridge ◽  
Significant Temperature ◽  
Thermal Bridges ◽  
Infrared Thermal Images ◽  
Heating Energy Demand

The “thermal bridges” are defined as an isolated building’s areas, where the construction elements have higher thermal conductivity, compared with the rest of the building envelope. Thus, at cold winter conditions, a significant temperature difference may occur between neighbouring solid and air volumes within the construction. Moreover, it has been documented, that the heating energy demand of a building may be increased with more than 30%, due to the existence of thermal bridges and the increased heat losses from the indoors. Consequently, in the recent years, norms and standards have been developed, for avoiding thermal bridges during the building design process. But still, thermal bridges exist in the indoor environment, especially in older buildings, where no energy efficient measures have been applied. That is why, the presented study focuses on instantaneous field measurements of thermal bridge parameters in real existing ground floor residential room. The thermal bridge propagation is analysed relative to the indoor and outdoor air temperature and relative humidity, as well as with infrared thermal images of the affected external walls. The achieved results give valuable information about the generic conditions for thermal bridge existence, without considering the building envelope properties.

scholarly journals Moisture accumulation analyses over windowpane, based on onsite measurements in sleeping room

2020 ◽  
Vol 207 ◽  
pp. 01003
Author(s):  
Martin Ivanov
Keyword(s):  
Building Envelope ◽  
Heat Losses ◽  
Building Construction ◽  
Dew Point ◽  
Point Temperature ◽  
Dew Point Temperature ◽  
Measurement Results ◽  
Lower Left Corner ◽  
Left Corner ◽  
Time Periods

The current paper presents moisture accumulation analyses over windowpane, based on onsite measurements in genuine sleeping room. During the measurements, the room was occupied with two adults and a baby, and the occupant’s behaviour was not additionally modified. The examination of the results represented the generic conditions for the windowpane condensation appearance, without taking into account the window assembly properties or the building construction. The studied windowpane has visually confirmed condensation in the lower left corner. This moisture accumulation is confirmed by the obtained measurement results near the windowpane, which clearly showed lower air temperature and higher relative humidity, compared with the rest of the occupied space. Thermal images also confirm this effect, and give better interpretation of the time periods, at which the surface temperature of the windowpane is lower than the dew point temperature in the affected zone. The analysed results offer important understanding of the interference of the different indoor parameters, related to the generic conditions for windowpane condensation appearance. These results may contribute the development of numerical model, capable to predict the heat losses and the moisture accumulation processes, in such affected areas from the building envelope.

scholarly journals Improving efficiency and lowering operating costs of evaporative cooling

2021 ◽  
Vol 338 ◽  
pp. 01027
Author(s):  
Jan Taler ◽  
Bartosz Jagieła ◽  
Magdalena Jaremkiewicz
Keyword(s):  
Electricity Consumption ◽  
Open Circuit ◽  
Dew Point ◽  
Operating Costs ◽  
Water Evaporation ◽  
Total Water ◽  
Point Temperature ◽  
Dew Point Temperature ◽  
Adiabatic Cooling ◽  
Positive Effect

Cooling towers, or so-called evaporation towers, use the natural effect of water evaporation to dissipate heat in industrial and comfort installations. Water, until it changes its state of aggregation, from liquid to gas, consumes energy (2.257 kJ/kg). By consuming this energy, it lowers the air temperature to the wet-bulb temperature, thanks to which the medium can be cooled below the ambient temperature. Evaporative solutions are characterized by continuous water evaporation (approx. 1.5% of the total water flow) and low electricity consumption (high EER). Evaporative (adiabatic) cooling also has a positive effect on the reduction of electricity consumption of cooled machines. Lowering the relative humidity (RH) by approx. 2% lowers the wet-bulb temperature by approx. 0.5°C, which increases the efficiency of the tower, operating in an open circuit, expressed in kW, by approx. 5%, while reducing water consumption and treatment costs. The use of the M-Cycle (Maisotsenko cycle) to lower the temperature of the wet thermometer to the dew point temperature will reduce operating costs and increase the efficiency of cooled machines.

scholarly journals Estimating Daily Dew Point Temperature Using Machine Learning Algorithms

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 582 ◽  
Author(s):  
Sultan Noman Qasem ◽  
Saeed Samadianfard ◽  
Hamed Sadri Nahand ◽  
Amir Mosavi ◽  
Shahaboddin Shamshirband ◽  
...  
Keyword(s):  
Meteorological Parameters ◽  
Gene Expression Programming ◽  
Machine Learning Algorithms ◽  
Dew Point ◽  
Coefficient Of Determination ◽  
Support Vector ◽  
M5 Model Tree ◽  
Point Temperature ◽  
Dew Point Temperature ◽  
Input Parameters

In the current study, the ability of three data-driven methods of Gene Expression Programming (GEP), M5 model tree (M5), and Support Vector Regression (SVR) were investigated in order to model and estimate the dew point temperature (DPT) at Tabriz station, Iran. For this purpose, meteorological parameters of daily average temperature (T), relative humidity (RH), actual vapor pressure (Vp), wind speed (W), and sunshine hours (S) were obtained from the meteorological organization of East Azerbaijan province, Iran for the period 1998 to 2016. Following this, the methods mentioned above were examined by defining 15 different input combinations of meteorological parameters. Additionally, root mean square error (RMSE) and the coefficient of determination (R2) were implemented to analyze the accuracy of the proposed methods. The results showed that the GEP-10 method, using three input parameters of T, RH, and S, with RMSE of 0.96°, the SVR-5, using two input parameters of T and RH, with RMSE of 0.44, and M5-15, using five input parameters of T, RH, Vp, W, and S with RMSE of 0.37 present better performance in the estimation of the DPT. As a conclusion, the M5-15 is recommended as the most precise model in the estimation of DPT in comparison with other considered models. As a conclusion, the obtained results proved the high capability of proposed M5 models in DPT estimation.

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