Energy is one of the most fundamental event of the universe and it is impossible to imagine an area where energy is not used. The energy demand is also increasing with the ever‐increasing population of the world. We also use energy to meet our heating and cooling needs. Heat loss from the exterior walls of buildings is important, so thermal insulation on the wall is very critical. In this study, optimum insulation thickness is determined for four provinces and two different insulation materials selected from four different climatic regions of Turkey. In order to calculate insulation thicknesses, the number of the degree‐day and exergetic environmental impact factor have been used. Natural gas is used as fuel. By using exergetic life cycle cost assessment method for rock wool and glass wool as insulation materials, the changes of CO2 emission values, the environmental impact factor, and energy saving values are determined for optimum insulation thickness. The optimum insulation thickness, which are calculated by using the number of the degree‐day and exergetic environmental impact factor for glass wool and rock wool is 0.1103 m and 0.04375 m for Antalya, 0.1667 m and 0.07292 m for Isparta, 0.1667 m and 0.0625 m for Bursa, and 0.2188 m and 0.1021 m for Erzurum, respectively. The reduction of carbon dioxide emission values for glass wool and rock wool 86% and 64% for Antalya, 90% and 76% for Isparta, 92% and 82% for Erzurum, and 90% and 73% for Bursa, respectively. Net exergetic environmental impact saving values for glass wool and rock wool: 589 mPts/m2‐yr and 342 mPts/m2‐yr for Antalya, 1,318 mPts/m2‐yr and 642 mPts/m2‐yr for Bursa, 1,315 mPts/m2‐yr and 878 mPts/m2‐yr for Erzurum, and 2,248 mPts/m2‐yr and 1,687 mPts/m2‐yr for Isparta, respectively.

The aim of this study is to determine the optimum heat insulation thickness for the glasswool and rockwool insulation material. Since natural gas is mostly used for heating in Turkey, it has been selected as fuel for the calculation. In order to calculate the optimum thickness of the insulation, the number of the degree-day and total environmental factor have been used. For the optimum insulation thickness, the decrease in exergy loss, CO2 emission and the fuel consumption were 75%, 73%, and 71% for the glasswool, respectively. On the other hand, for the rockwool, they were 35%, 18%, and 43%, respectively. Optimum thickness was calculated as 0.40 m for glasswool, and 0.18 for the rockwool.

Recent developments in technology increase the application area of electronic systems used in cars and commercial vehicles day by day. Along with the increase in the features expected from the vehicles, the battery capacities required to meet the desired features also increase. Especially in commercial vehicles, high-capacity battery systems are used depending on the function of the vehicle. Circuit breaker systems providing high voltage and current are used to intervene in the event of a possible problem from the batteries. During the operation of the vehicle, heat is generated due to the high current passing through the circuit breakers. In this study, different materials and surface contact forms were examined to solve the heating problem of circuit breakers operating at high voltage and current values. AgSnO2 and AgCdO coating materials were used for surface coatings of rivets used in circuit breakers. Moreover, rivet groups with various surface contact geometries such as flat–flat and curved–flat were used for each material. After applying 24 V–250 A values to the different materials and rivets of different surface shape geometries, thermal and metallographic analyses were performed. The experimental study showed that the best thermal results under resistive load are formed by the curved–flat contact geometry of the AgSnO2 coating material.