Determination of Temperature Distributions for the Sky Based on the Results of Measurement with an Infrared Camera

The surroundings of objects in an open atmospheric space usually consist of a hypothetical surface of the sky and the surface of the ground. The aim of thermovision examination of objects located in open atmospheric space, especially buildings, is to determine the amount of heat loss or to assess the insulation quality parameters of walls, roofs and other building partitions. The tested surfaces, including elements of the outer shell of buildings, are often located at different angles to the ground surface and the sky. For the needs of thermovision testing of the considered objects and calculations concerning the radiation heat transfer, it is necessary to know the radiation parameters of the sky. These parameters include the equivalent radiative ambient temperature needed for thermovision measurements (including the temperature of the sky and the ground) and the overall radiative ambient temperature, which determines the heat loss by radiation from the tested surface. The article describes the method of determining the values of these temperatures on the basis of measuring the temperature of the sky with the use of a long-wave infrared camera and calculations. In order to verify the developed method, the results obtained with the use of the above-mentioned method were compared with the results obtained with the use of a pyrgeometer. The verification comprised the comparison of the heat flux of radiation from the sky, calculated on the basis of infrared camera measurements, with the energy flux emitted by the sky and measured with a pyrgeometer. The result of the verification is satisfactory.

Fuel savings by using better-quality insulation in refrigerated vans

An additional attention must be payed to the energy efficiency of refrigerated vans transporting perishable foodstuffs, because inefficient operation of refrigeration units installed on these vehicles increases fuel consumption and exhaust gases emissions. The amount of fuel consumed by mechanical refrigeration unit drive can be reduced in many ways. This paper is analysing the impact of thermal insulation quality on the fuel consumed by mechanical refrigeration unit installed on a typical van. The results of the research show that by choosing better-quality thermal insulation around € 420 can be saved annually on fuel consumed by mechanical refrigeration unit driven by vehicle's engine while transporting deeply frozen fish at -20 °C (or other foodstuffs at given temperature). If the van is transporting raw meat (for example) at 0 °C annual savings can be around € 110. When the van is used for transport of deeply frozen fish the investment will pay off after 3.5 years of vehicle exploitation, while if the raw meat is transported the investment will pay off after approximately 14 years. The analysis includes the price of insulating the van, current fuel price in Serbia, as well as the average monthly temperatures in the territory of Belgrade, Serbia.

Breakdown Voltage Characteristic Of Mineral Oil In Power Transformer 16 Mva Updl Semarang

The transformer is one of the most important equipment in the electric power system, which is to distribute power from power plants to the load centers by step-up or step down the voltage. Transformer is expect to have a high level of reliability. One of the causes of damage to the power transformer is its insulation system. Mineral oil is an insulator that is widely used in power transformers. One of the important parameters in oil type insulation is the breakdown voltage value, the greater breakdown voltage value, as better the insulation quality. In this research, a breakdown voltage test is carried out on a Shell Diala B transformer oil type regarding the IEC 60156-95 standard. The results showed a breakdown voltage in the power transformer oil at UPDL Semarang of 49.2 kV. These results have met the feasibility standard of transformer oil, based on the IEC standard the value of breakdown voltage of liquid type insulation is 30 kV.

Moisture Behavior of Thermal Insulation Coating Consisted of Vacuum-Hollow Nano-Ceramic Microspheres

Nanotechnology-based thermal insulation materials have appeared in building industry in the last two decades. Among them thermal insulating coatings consisted of vacuum-hollow nano-ceramic microspheres are the subjects of most professional discussion. Most studies about these coatings focus only on examination of thermodynamic properties, because there is still no consensus in academic circles about thermodynamic processes inside nano-ceramic coatings. These professional discussions distract attention from other unknown but also important material properties, like behavior by contact with moisture. This paper summarizes the results of moisture behavior tests with nano-ceramic thermal insulation coatings which were conducted to determine the time trend of water absorption, as well as volume, mass and thermal insulation quality changes caused by increasing moisture content. Analyzing the results mathematical connections were found to describe the relation between water content, dimensional and thermal conductivity changes.

Energy demand of occupant’s spatial modification in residential buildings. Case study of Médéa, Algeria

Housing is rated as one of the most commonly consuming energy field in terms of energy end-use with 41%. Regarding the transformations dealt by dwellers for functional and social uses. The aim of this paper is: Firstly, to highlight the non-controlled transformation process made by the occupant in Algeria; Secondly, to explore the impact of the energy load of such spatial transformations. The question is approached in two tracks, (i) Through Ecotect software’s simulations (ii) and measurements through a collection of energy end-use data. Basically, the energy demand is bound to dwelling’s spatial and socioeconomic criteria. Three cases studied showed consequently 2 positive and 1 negative energy load, in which two explanations may be given: Insulation quality that occupant is lacking facilities to improve may be stated as a physical explanation, as well as for the socio economic one, the density per dwelling plays a major role, but it is the income which explains within the two approaches more than 87% of the energy end use.

Impact of External Shading on Light Comfort and Energy Efficiency in Apartment Buildings

The paper is focused on an example of volume solution of a superstructure designed within allowable legislative limits and its impact on light comfort in shaded flats. It deals with issues such as : optimizing allowable amount of external shade in relation to sustainable hygienic quality of residential environment, an impact of superstructure ́s shade on insolation time in affected flats and consequently on passive solar gain intensity of apartment buildings, as well as evaluation of energy efficiency of infill walls in compensating of their heat loss in heating period, depending on the amount of external shading, their orientation, and thermo-insulation quality in all model scenarios - current, legislatively allowable, and optimized. It solves compatibility of optimized shading in terms of hygienic quality in relation to the increased efficiency of solar gains utilization to cover heat loss by heat-exchange shell in contemporary and prospective low-energy buildings.