Effect of fuel type on the optimum thickness of selected insulation materials for the four different climatic regions of Turkey

The optimum insulation thickness of the external wall for four various cities from four climate zones of Turkey, energy savings over a lifetime of 10 years and payback periods are calculated for the five different energy types and four different insulation materials. Foamboard 3500, Foamboard 1500, extruded polystyrene and fiberglass as insulation material are selected. In this study, it is calculated the value of the amount of the net energy savings using the P₁–P₂ method. The results show that optimum insulation thicknesses vary between 1.06 and 7.64 cm, energy savings vary between 19 $/m² and 47 $/m², and payback periods vary between 1.8 and 3.7 years depending on the city and the type of fuel. The highest value of energy savings is reached in A?r? for LPG fuel type, while the lowest value is obtained in Ayd?n for natural gas.     

A study on optimum insulation thickness in walls and energy savings in Tunisian buildings based on analytical calculation of cooling and heating transmission loads

In Tunisian climate, both heating in winter and cooling in summer are required to reach comfort levels. Due to the significant increase in building energy consumption, insulation of external walls is recently applied with a thickness typically ranging between 4 cm and 5 cm regardless of structure and orientation of walls and of economic parameters. In the present study, optimum insulation thickness, energy saving and payback period are calculated for a typical wall structure based on both cooling and heating loads. Yearly transmission loads are rigorously estimated using an analytical method based on Complex Finite Fourier Transform (CFFT). Considering different wall orientations, the west and east facing walls are the least favourite in the cooling season, whereas the north-facing wall is the least favourite in the heating season. A life-cycle cost analysis over a building lifetime of 30 years shows that the south orientation is the most economical with an optimum insulation thickness of 10.1 cm, 71.33% of energy savings and a payback period of 3.29 years. It is noted that wall orientation has a small effect on optimum insulation thickness, but a more significant effect on energy savings which reach a maximum value of 23.78 TND/m² in the case of east facing wall. A sensitivity analysis shows that economic parameters, such as insulation cost, energy cost, inflation and discount rates and building lifetime, have a noticeable effect on optimum insulation and energy savings. Comparison of the present study with the degree-days model is also performed.     

Optimization of insulation thickness for external walls using different energy-sources

In countries that import most of their energy, like Turkey, energy saving and the effective usage of energy become much more important. Energy consumption for heating is too high in Turkey because buildings have almost no insulation. Also the high prices of heating energy in Turkey, emphasize the need for energy saving. Therefore, the optimum insulation-thickness of the external wall for the five different energy-sources (coal, natural gas, LPG, fuel oil and electricity) and two different insulation materials (expanded polystyrene, rock wool) are calculated for Denizli. The optimization is based on a life-cycle cost analysis. According to the results, the optimum has been obtained by using coal as the energy source and expanded polystyrene as the insulating material. When the optimum insulation-thickness is used the life cycle saving and payback period are 14.09 $/m² and 1.43 years, respectively.     

Effect of wall orientation on the optimum insulation thickness by using a dynamic method

A comprehensive economic analysis has been performed to inter-relate the optimum thickness of insulation materials for various wall orientations. The yearly cooling and heating transmission loads of building walls were determined by use of implicit finite-difference method with regarding steady periodic conditions under the climatic conditions of Elaz??, Turkey. The economic model including the cost of insulation material and the present value of energy consumption cost over lifetime of 10 years of the building was used to find out the optimum insulation thickness, energy savings and payback periods for all wall orientations. Considered insulation materials in the analysis were extruded polystyrene and polyurethane. As a result, the optimum insulation thickness of extruded polystyrene was found to be 5.5 cm for south oriented wall and 6 cm for north, east and west oriented walls. Additionally, the lowest value of the optimum insulation thickness and energy savings were obtained for the south oriented wall while payback period was almost same for all orientations.     

Thermoeconomic analysis method for optimization of insulation thickness for the four different climatic regions of Turkey

Thermal insulation is one of the most effective energy-conservation measures in buildings. For this reason, the energy savings can be obtained by using proper thickness of insulation in buildings. In this study, the optimum thickness of insulation considering condensed vapor in external walls are found by using exergoeconomic analysis. The four various cities from four climate zones of Turkey, namely, Antalya, ?stanbul, Elaz?? and Erzurum are selected for the analysis. The optimum insulation thickness for Antalya, ?stanbul, Elaz?? and Erzurum are obtained as 0.038, 0.046, 0.057 and 0.0739 m at indoor temperature of 20 °C, respectively. The results show that the optimum insulation thickness at the indoor temperature of 18 and 22 °C are determined as 0.0663 and 0.0816 m for the city of Erzurum, respectively. The energy saving for the city of Erzurum is found as 77.2% for the indoor temperature of 18 °C, 79.0% for the indoor temperature of 20 °C and 80.6% for the indoor temperature of 22 °C, when the optimum insulation is applied.     

Optimum insulation thickness of walls for energy-saving in hot regions of India

In India, the energy consumption in the building sector is rapidly increasing due to improvement in living standards. Effective thermal insulation of building walls is one of the most effective energy conservation measures for heating, ventilation, and air conditioning applications in buildings. In this study, the thermoeconomic optimisation of insulation thickness on walls of buildings is analysed based on degree days. Thermoeconomic parameters such as optimum insulation thickness, annual electrical energy consumption, annual energy cost and payback period is determined for three different insulation materials for the cities located in India. Database on insulation materials for five cities of India are provided.     

A review of the economical and optimum thermal insulation thickness for building applications

Energy conservation is an increasingly important issue for the residential sector. Therefore, attention towards the thermal performance of building materials, particularly thermal insulation systems for buildings, has grown in recent years. In this study, a literature review on determining the optimum thickness of the thermal insulation material in a building envelope and its effect on energy consumption was carried out. The results, the optimization procedures and the economic analysis methods used in the studies were presented comparatively. Additionally, a practical application on optimizing the insulation thickness was performed, and the effective parameters on the optimum value were investigated.     

Determination of optimum insulation thickness of external walls with two different methods in cooling applications

Thermal insulation is one of the most effective energy conservation for the cooling applications. For this reason, determination of the optimum thickness of insulation and its selection is the main subject of many engineering investigations. In this study, the optimum insulation thickness on the external walls in the cooling applications is analyzed based on two different methods used to determine annual energy consumption. One of the methods is the degree-hours method (Method 1) that is the simplest and most intuitive way of estimating the annual energy consumption of a building. The other is the method (Method 2) which using the annual equivalent full load cooling hours operation of system. In this paper, a Life Cycle Cost (LCC) analysis is used to evaluate accuracy of these methods, and the results are compared. The results show that the life cycle savings are overestimated by up to 44% in Method 2, while the optimum insulation thickness and payback period are respectively overestimated by up to 74% and 69% in Method 1.     

A study on residential heating energy requirement and optimum insulation thickness

Heat loss from buildings has a considerable share in waste of energy especially in Turkey since no or little insulation is used in existing and new buildings. Therefore, energy savings can be obtained by determining of heat loss characteristics with using proper thickness of insulation. For this purpose, in this study, calculations of optimum insulation thickness are carried out on a prototype building in Bursa as a sample city. Considering long term and current outdoor air temperature records (from 1992 to 2005), degree-hour (DH) values are calculated, and the variation of annual energy requirement of the building is investigated for various architectural design properties (such as air infiltration rate, glazing type, and area). Then, the effects of the insulation thickness on the energy requirement and total cost are presented. Based on life cycle cost (LCC) analysis, the optimum insulation thicknesses are determined for different fuel types. As a conclusion, the length of the heating period is average 221 days, and the mean heating DH value is found as 45 113.2 besides changing between 38 000 and 55 000. The optimum insulation thicknesses for Bursa vary between 5.3 and 12.4 cm depending on fuel types. In addition to this, the variation in Turkey is more dramatically.     

Determination of optimum insulation thicknesses of the external walls and roof (ceiling) for Turkey's different degree-day regions

The external walls and roof of a building are the interface between its interior and the outdoor environment. Insulation of the external walls and roof is the most cost-effective way of controlling the outside elements to make homes more comfortable. Although insulation is generally accepted as a factor increasing the building costs, with the calculations we have shown that this is not the case. Fuel consumption and operational costs are reduced by increasing the thickness of the external walls and roof (ceiling), despite an increase in the investment costs. According to Turkish Standard Number 825 (TS 825), there are four different degree-day (DD) regions, and the required heat loads for the buildings in these regions exhibit large differences. Therefore, a method based on costs is needed for the determination of optimum insulation thicknesses of different DD regions. In this study, optimum insulation thicknesses for different DD regions of Turkey, namely, Izmir (DD: 1450), Bursa (DD: 2203), Eski?ehir (DD: 3215) and Erzurum (DD: 4856), have been determined for a lifetime of N years, maximizing the present worth value of annual energy savings for insulated external walls.     

Evaluation of methods used to determine realized energy savings

Most methods to determine realized total energy savings at national or sectoral level make choices, or neglect problems, which hamper the calculation of sound and useful energy-saving figures. Issues are the choice of the right aggregation level, the appropriate variables to construct a reference energy consumption trend, the energy quantities to be applied and interaction between various effects. Uncertainty margins for results lack in most presentations as well. This paper presents six methods, illustrates the adverse effects of certain choices and problems, and investigates how these methods deal with them. The methods are scored with respect to the issues mentioned above. Finally, a number of improvements are suggested, among which the use of final energy demand expressed in primary energy units, and bottom-up analyses at the level of real saving options. The last option is the more important, as it could provide top-down evaluation results (total savings from decomposition) as well as bottom-up policy monitoring results, both being crucial to new European energy-saving policy.     

Energy consumption,energy savings,and emission analysis in Malaysian office buildings

This paper is concerned with the estimation of energy use in office buildings in Malaysia and with the energy use of major equipment. Energy intensity (EI) – a measure of a building's energy performance – is estimated for Malaysia and compared with a number of selected countries. Air conditioners are shown to be the major energy users (57%) in office buildings, followed by lighting (19%), lifts and pumps (18%) and other equipment (6%). It is estimated that 77,569 MWh of energy can be saved and a huge reduction of emissions achieved through the application of advance glazing, compact fluorescent lamps (CFL), insulation, housekeeping, and by raising thermostat set point temperature of air conditioners, and reducing EI.     

Energy use,energy savings and emission analysis in the Malaysian rubber producing industries

In this paper an analysis of energy use and energy conservation in the Malaysian rubber producing industries is presented. It has been found that rubber industries consume a substantial amount of energy. Excessive use of energy is usually associated with many industrial plants worldwide, and rubber plants are no exception. This study is based on the realization that enormous potential exists for cost-effective improvements in the existing energy-using equipment. Through the method of a walkthrough energy audit, power rating, operation time of energy-consuming equipment/machineries and power factor were collected. The data were then analyzed to investigate the breakdown of end-use equipment/machineries energy use. The results of the energy audit in the Malaysian rubber and rubber producing industries showed that the electric motor accounts for a major fraction of total energy consumption followed by pumps, heaters, cooling systems and lighting. Since the electric motor takes up a substantial amount of the total energy used in rubber industries, energy-savings strategies such as the use of high efficient motors, and variable speed drive (VSD) have been used to reduce energy consumption of motors used in rubber industries. Energy-savings strategies for compressed-air systems, boilers, and chillers have also been applied to estimate energy and cost savings. It has been found that significant amount of energy and; utility bills can be saved along with the reduction of emission by applying the foretold strategies for energy using machineries in the rubber industries.     

The unrecognized contribution of renewable energy to Europe's energy savings target

We show that renewable energy contributes to Europe's 2020 primary energy savings target. This contribution, which is to a large extent still unknown and not recognized by policy makers, results from the way renewable energy is dealt with in Europe's energy statistics. We discuss the policy consequences and argue that the ‘energy savings’ occurring from the accounting of renewable energy should not distract attention from demand-side energy savings in sectors such as transport, industry and the built environment. The consequence of such a distraction could be that many of the benefits from demand-side energy savings, for example lower energy bills, increase of the renewable energy share in energy consumption without investing in new renewable capacity, and long-term climate targets to reduce greenhouse gas emissions by more than 80%, will be missed. Such distraction is not hypothetical since Europe's 2020 renewable energy target is binding whereas the 2020 primary energy savings target is only indicative.     

Determination and selecting the optimum thickness of insulation for buildings in hot countries by accounting for solar radiation

Determination and selecting the optimum thickness of insulation is the prime interest of many engineering applications. One of those applications is insulating buildings with an appropriate insulation. Calculations have been done for the determination of the optimum thickness of insulation for some insulating materials used in order to reduce the rate of heat flow to the buildings in hot countries. Reducing heat flow rate would reduce the electricity cost for the house lifetime. The solar energy radiation is calculated and used to calculate the solar-air temperature which is employed for the determination of the heat flow rate. Some results were obtained for a typical house in Qatar which is an example of hot area. The wallmate insulation is found to have the best performance for houses in Qatar.     

Determining the optimum economic insulation thickness of double pipes buried in the soil for district heating systems

The insulation thickness (IT) of double pipes buried in the soil (DPBIS) for district heating (DH) systems was optimized to minimize the annual total cost of DPBIS for DH systems. An optimization model to obtain the optimum insulation thickness (OIT) and minimum annual total cost (MATC) of DPBIS for DH systems was established. The zero point theorem and fsolve function were used to solve the optimization model. Three types of heat sources, four operating strategies, three kinds of insulation materials, seven nominal pipe size (NPS) values, and three buried depth (BD) values were considered in the calculation of the OIT and MATC of DPBIS for DH systems, respectively. The optimization results for the above factors were compared. The results show that the OIT and MATC of DPBIS for DH systems can be obtained by using the optimization model. Sensitivity analysis was conducted to investigate the impact of some economic parameters, i.e., unit heating cost, insulation material price, interest rate, and insulation material lifetime, on optimization results. It is found out that the impact of sensitivity factors on the OIT and MATC of DPBIS for DH systems is different.     

Verification of electrical energy savings for lighting retrofits using short- and long-term monitoring

This paper presents the verification of the annual electrical energy savings associated with lighting retrofits using short- and long-term monitoring. The effort was part of a US utility-sponsored energy efficiency program to reduce energy consumption in commercial and industrial facilities. Although this paper describes the verification procedures in three facilities, the recommended methods have broad application. In this study, we first conducted lighting energy audits to identify lighting efficiency measures at three facilities, namely an office building, an industrial manufacturing plant, and a city hospital. Then, we estimated the lighting energy savings for the facilities and sought to present the results in a meaningful form. Actual energy savings were measured using short- and long-term monitoring. In all cases, the energy savings measured were within 30% of the projected energy savings.     

Potential energy savings and environmental impacts of energy efficiency standards for vapor compression central air conditioning units in China

Owing to the rapid development of economy and the stable improvement of people's living standard, central air conditioning units are broadly used in China. This not only consumes large energy, but also results in adverse energy-related environmental issues. Energy efficiency standards are accepted effective policy tools to reduce energy consumption and pollutant emissions. Recently, China issued two national energy efficiency standards, GB19577-2004 and GB19576-2004, for vapor compression central air conditioning units for the first time. This paper first reviews the two standards, and then establishes a mathematic model to evaluate the potential energy savings and environmental impacts of the standards. The estimated results indicate implementing these standards will save massive energy, as well as benefit greatly to the environment. Obviously, it is significant to implement energy efficiency standards for central air conditioning units in China.     

Improving thermal performance of building walls by optimizing insulation layer distribution and thickness for same thermal mass

Dynamic thermal characteristics of insulated building walls with same thermal mass are studied numerically with optimized insulation thickness under steady periodic conditions using the climatic data of Riyadh. Insulation is effected through use of one, two and three layers of insulation, the locations of which are varied in order to achieve the best performance. Insulation layer(s) thicknesses are optimized by minimizing the total cost of insulation and energy consumption using the present worth method. The results show that the optimum thickness of a single insulation layer is independent of its location in the wall; and that, when more than one insulation layer is used, their total optimum thickness is the same as the optimum thickness of a single layer. As a consequence, walls thermal resistances (R-values) are equal under optimum conditions; however, peak load, time lag, and decrement factor are found to be substantially different. The best overall performance is achieved by a wall with three layers of insulation, each 26-mm-thick, placed at inside, middle and outside followed closely by a wall with two insulation layers, each 39-mm-thick, placed at middle and outside. Comparing performance of the best wall with that of a wall with one layer of insulation, 78-mm-thick, placed on the inside, the following improvements are achieved: 100% increase in time lag from 6 h to 12 h; 10-fold decrease in decrement factor; 20% decrease in both peak cooling and heating transmission loads, and 1.6% and 3.2% decrease in yearly cooling and heating transmission loads, respectively. It is emphasized that all walls have the same optimized R-value and same thermal mass and therefore all improvements achieved are solely due to the developed distribution of insulation layers.