Achieving Energy Savings and Addressing Detail Issues in Exterior Wall Thermal Insulation

Summary

If thermal insulation in buildings does not receive the necessary attention and effective energy conservation policies are not applied, our dependence on foreign energy sources will increase further in the coming years and we will face environmental problems. This study aimed to provide energy savings through thermal insulation of building external walls and to investigate detail problems. Examples were selected from practice and their details and problems were examined. In particular, due to high heat losses, more energy is consumed in buildings and fuel costs also increase. Examinations conducted revealed that thermal insulation standards were not followed during the application of building external facades, and thermal insulation materials required by standards were not used. The study provided general information on energy savings through thermal insulation, and regarding applications related to building thermal insulation and encountered problems, only cross-sections related to external walls were detailed in drawings to examine whether condensation problems existed. In the conclusion section, it was noted that energy resources are consumed more in buildings without thermal insulation, and results obtained from the examined cross-sections were presented. For solving the problems, recommendations were made regarding compliance with standards, development of energy-efficient thermal insulation details without condensation problems, and drawing the interest of academic and sectoral fields.

1. Introduction

As a result of unconscious use of energy resources, the ecological balance of the world is changing, and problems of not leaving a livable environment for future generations are emerging. Today, due to the decreasing energy resources day by day, rising heating costs, greenhouse gases affecting the atmosphere, and fossil fuel waste, it is necessary to comply with thermal insulation rules specified in standards for buildings and to use energy efficiently. Through thermal insulation applications in buildings, the amounts of energy used for heating buildings can be limited, thus energy-efficient buildings can be produced. Through thermal insulation in buildings, heating and cooling costs are reduced and since a comfortable environment suitable for building physics conditions is provided to occupants, energy savings are also achieved. Particularly in winter months, due to the abundance of fossil fuels used to heat buildings, air pollution problems are experienced, and residents in uninsulated buildings complain about excessive and expensive heating costs. The main problem in this regard has been found to stem from the fact that the issue of energy savings through thermal insulation has not yet been understood, environmental awareness has not been established, necessary care has not been given to thermal insulation details in buildings, thermal insulation standards for buildings are not complied with, and adequate inspections have not been conducted in practice. In this study, the issue of energy savings through thermal insulation of building external walls was explained with examples from practice, and analysis of external walls and their details was conducted.

2. Effect of Building Thermal Insulation on Energy Savings and the Environment

Thermal insulation is important in many respects, generally speaking: energy savings, prevention of environmental pollution, provision of comfort conditions, protection of building materials from physical environmental conditions, and reduction of operating costs. However, there are matters that must be considered during the application of insulation. Designs and projects should be made according to standards, system cross-sections and point details should be drawn, the technical properties of materials to be used for thermal insulation should be known in advance, correct products should be selected, and applications must be carried out error-free by expert personnel. This section explains how to achieve energy savings through thermal insulation, the effect of uninsulated buildings on environmental pollution, thermal insulation rules, and what information is required in projects.

2.1. Achieving Energy Savings Through Thermal Insulation

The conscious use of energy in all areas is an important responsibility for the economy and human health as much as for the future, because energy is obtained from limited natural resources at very high costs. Standards and regulations regarding thermal insulation in buildings and its application have become a legal obligation[1]. Heat losses in buildings, although varying according to the building's architectural design and condition, generally consist of: 40% from external walls, 30% from windows, 7% from roofs, 6% from basement floors, and 17% from air leakage for a multi-storey dwelling. In a single-storey dwelling, heat losses are determined as 25% from external walls, 22% from the roof, 20% from windows, 20% from the basement, and 13% from air leakage[2]. As can be understood from these figures, the highest heat losses in buildings come in order from external walls, windows, ceiling-roof, and floor sections[2]. For this reason, the research conducted focused on external walls and details where the most heat loss occurs. The foundation of energy savings in buildings lies in correct detailing, quality material use, and error-free application with proper workmanship. Thermal insulation work should actually be a specialized field. For this reason, insulation applications must be carried out by expert personnel qualified in the field, energy savings must be achieved through thermal insulation, and comfortable environments must be provided to occupants.

2.2. Effect of Uninsulated Buildings on Environmental Pollution

Due to the lack of necessary attention to thermal insulation in buildings and non-compliance with rules specified in standards, the amount of energy consumed for heating is more than it should be. Because quality fuels for heating are expensive, our population with weak economic power is turning to cheaper but more polluting fossil fuels and particularly lignite. In our country, natural gas, domestic and imported lignite coal, liquid fuels, heating oil, petroleum-based waste oils, wood, etc. are generally used to heat buildings in winter. In industrial areas, scrap car tires are cut up and burned[3]. It has been observed through on-site inspections that "TS. 825. Thermal Insulation Rules Standard for Buildings" is not complied with. For this reason, in winter months, more energy than necessary is consumed to heat uninsulated buildings and fossil fuel consumption also increases. Thus, environmental pollution occurs. Due to harmful gases and particles, in terms of atmospheric pollution, air pollution and environmental problems have been experienced in major cities in winter months in recent years. In a well-insulated environment, with proper combustion technique, a large portion of the energy obtained can be used as useful heating energy and the environmental pollution-causing effect of the fuel used can be reduced to minimum levels.

2.3. Thermal Insulation Rules and Required Information

The purpose of standards related to thermal insulation rules is to limit the amount of energy used for heating buildings, thus increase energy savings, and determine the calculation values to be used during energy requirement calculations. These calculations determine the design option that will provide ideal energy performance. Net heating energy consumption of buildings is determined. If insulation is considered in existing structures, the amounts of savings that energy conservation measures to be applied will provide are determined before the project is implemented. All reinforced concrete elements located on external surfaces must be insulated so as not to create thermal bridges[4]. With thermal insulation, the interior environment with volume is protected from excessive energy loss in winter and excessive energy gain in summer. The thermal insulation project must specify the materials used on the heat-losing surfaces of the building, the arrangement of these materials within the element, their thicknesses, the areas of elements, and "U (thermal transmittance coefficient)" values. Heat losses, heat gains, gain/loss ratio, gain utilization factor, magnitudes of monthly and annual heating energy requirements, "building's specific heat loss" and "annual heating energy requirement" specified in TS.825 standard should be given in tabular form, annual heating energy requirement should be calculated and stated as appropriate. The type of glass and frames used in window systems on external facades, window areas for all directions separately, and "U" values must be specified. Details of wall-window, wall-ceiling, wall-floor connection points must be shown with drawings. Condensation that may occur on the heat-losing surfaces of the building should be investigated and necessary drawings and calculations should be made[4]. Recommended maximum "U" values by region and degree day zones by city are divided into 5 groups (Table 1). Accordingly, the "U" values recommended in standards should be taken into account. The values provided in standards in calculations are maximum values. Values resulting from calculation should be less than or equal to values provided in standards. In calculating external facade column thicknesses (d), the reinforced concrete beam thickness at the point where the column connected to the beam is joined will be taken as the column thickness, and it is not considered that the column thickness is greater than the beam thickness. All reinforced concrete elements on external surfaces (column, beam, bond beam, and shear wall, etc.) must be insulated. Since the application of energy performance certificates for new buildings commenced from 2011 onwards, architects preparing architectural designs and details and drawing system cross-sections will need to work together with relevant engineers.

3. Analysis of Thermal Insulation Applications and Details in External Walls

Thermal insulation materials are generally a mixture of heterogeneous materials. They generally consist of a skeleton frame formed by an outer wall surrounding air-filled cells. As a natural consequence of this structure, thermal insulation materials are light. Thermal insulation materials should have sufficient compression-tension strength, desired vapor diffusion resistance, low unit volume weight, and high heat retention value. They should have dimensional stability and not change in volume and shape with various external factors. When applied to the location of use, operations such as cutting, drilling, and gluing should be easily performable. They must be resistant to chemical agents and not lose their quality. Thermal insulation materials must be non-flammable and flame-resistant. They must not harbor parasites. They should not be affected by water and moisture. They must work compatibly with other materials. If necessary, plaster can be applied over them. In order to provide service for many years, they must not rot or deteriorate. They must be odorless. They must be readily available, inexpensive, and economical[5]. Heat losses in buildings come from solid surfaces forming the wall, from openings in the surface, and from the building external envelope. Heat losses can occur directly from these areas or can be thermal bridges through frames, glass, window, door cases and leaves, and at the junction points of different materials. At these points, especially at details that have not been properly resolved or where an optimal solution has not been provided for that point, heat losses can become more concentrated. Heat losses are observed through the wall material located above the window and door opening surrounding the structure and through gaps between the door and threshold. Additionally, another problem is the heat difference between the building's load-bearing system; column-beam, and wall elements using thermally insulated fill materials, and condensation occurring in reinforced concrete elements especially on north facades causing problems. To prevent this and for heat gains, examples related to insulating the building (from inside, middle, and outside) are widely used today[6]. Sustainability in buildings simply means using energy efficiently. Traditional buildings have savings. In today's buildings, savings have been forgotten. Very large mistakes and errors are being made in material use. There are many problems from material production to application. Materials to be used in the building should be well thought out in the design phase and good decisions should be made for selections during the design phase. Correct application of materials, their selection according to their function within the whole, is extremely important. Correct, proper use, correct detailing, and the technique of expressing this is extremely important. Applying the selected material is even more important. One of the problems encountered in practice is that due to faulty workmanship by non-expert applicators in retrofitted insulation applications, the expected function of the material is not fulfilled. Architects should consider insulation-related problems from the initial stages of design itself. They should treat insulation as a design criterion that must be done, select materials accordingly, detail it, and provide the applicator with detailed design in system cross-sections and, if necessary, point details as drawings. In the design phase and detailing, the thicknesses, order, shapes, and dimensions of materials to be used must be specified[7]. In most architecture schools in our country, thermal insulation, standards, and building application project courses are covered superficially. However, according to TS.825, building physics problems regarding thermal insulation should be specially taught to architects, and designer architects competent in calculations, problems, and details work in coordination with building owners, material manufacturers, engineers, applicators, workers, and laborers and can realize their designs 100%. Otherwise, as it is today, necessary attention is not given to building physics and application project courses in university architecture education. In application projects submitted to municipalities, point details are multiplied through photo montage, and connection between architectural projects and insulation details cannot be established. In most municipalities' project control departments, it is observed that experts and architects knowledgeable about TS.825 standards and calculations are either absent or extremely limited. In projects approved by professional associations, projects, system cross-sections, thermal insulation, and point details are not examined. Everyone is looking at the money they received for their receipt. Thermal insulation and energy savings are treated as if they are the responsibility of other engineering fields, and the actual responsibility for the issue cannot be clearly determined. Because universities, municipalities, building owners, and architects do not attach importance to the issue and delegate it to different engineering fields, the bill for thermal insulation and energy savings in buildings is paid by the people of our country, which is 70% dependent on foreign energy sources. As long as the same system continues, it is foreseen that they will continue to pay. The surface heat transmission (convection) values (R) used in buildings and values to be taken in details are given in TS. 825 (December 2013). For External Walls, Ri (0.13 m2K/W), Re (0.04 m2K/W) should be taken. In wall components made from various layers, incorrect arrangement of layers reduces the thermal insulation capability of the component and causes condensation. Condensation occurring within the building component will reduce the thermal transmittance resistance of the component as well as cause structural damage. Sweating and condensation events reduce the value of heat-retaining materials in building elements, cause surface efflorescence on facades, and cause swelling and peeling of cladding materials. Therefore, in detailing, especially condensation calculations must be made and materials must be placed side by side according to results from these calculations. To prevent condensation in building elements, good ventilation in the space must be provided, and materials with higher vapor transmission resistance on the warm side than those on the cold side must be used[8]. In various cities of our country, it has been determined that there are still buildings where thermal insulation is not applied. In mass housing applications where only external plaster, 19 cm thick vertical hole brick wall, and internal plaster are applied, insulation is not applied on the external facades (Figure 1, Figure 2). Later, when residents in uninsulated buildings encounter excessive fuel costs and condensation problems in buildings, they come to believe in the necessity of their buildings being thermally insulated.

Heat loss from external walls of buildings increases according to the building's height. External walls of buildings are directly exposed to atmospheric conditions.

In order to obtain spaces more secure against the adverse effects of environmental conditions and suitable for building physics conditions, external walls of buildings should be covered with thermal insulation materials in accordance with standards and regulations. As the existing uninsulated building has increased fuel costs and condensation problems, the site management made a joint decision and decided to carry out thermal insulation on their buildings (Figure 3, Figure 4). In the applications carried out, it is observed that no calculations or scientific studies according to standards have been made. Applications are being carried out according to the price and system agreed upon by the cladding system application company. Condensation problems and thermal insulation calculations according to standards are not being made. Various problems occur in retrofitted thermal insulation applications. It was noted that due to the thicknesses of thermal insulation materials, difficulties are experienced in application on sills, coatings to be applied over thermal insulation materials, and window edges (Figure 5, Figure 6). External walls can be preferred as insulated from inside, middle (insulation between two walls, sandwich), and outside (Figure 7, Figure 8). In insulation, thermal bridges must not be created at columns, beams, bond beams, shear walls, and lintels attached to the external wall. Building elements creating thermal bridges must be insulated.

Insulation of columns, beams, and shear walls can be done both by placing insulation sheets into the formwork on concrete walls and by being fastened to the external surface after concrete is poured. These building elements can be insulated from outside and must be solved within the limit values in accordance with the principles given in the thermal insulation regulation.

In cross-sections where different materials are used, the formation of thermal bridges must be solved with appropriate details. Thermal insulation applied from outside must be fixed to walls with anchors. Connection elements must be selected from materials that will not create thermal bridges. A reinforcement mesh should be placed on the insulation, then plaster should be applied over it. When plaster is applied directly on the thermal insulation material without using reinforcement mesh, the plaster is seen to fall off later.

In the research conducted, reinforced concrete shear walls, columns, beams, etc., solid or vertical hole bricks, horizontal hole bricks, volcanic block bricks, and aerated concrete walls (normal mortar joints) were used in the external walls of buildings.

In terms of thermal insulation material, it was determined that 90% of uninsulated applications and 10% or lower levels of insulated applications. In thermally insulated applications retrofitted to buildings later, problems that are left unresolved in details on sills, windows, doors, balconies, projections, edges, and corners, and in drip edges are encountered (Figure 10). As thermal insulation materials; polyurethane (PUR), extruded polystyrene foam (XPS), expanded polystyrene foam (EPS) are used. Uninsulated (Figure 11) and thermally insulated section details (Figure 12) are provided.

Water vapor produced in the interior environment damages buildings and materials. Water vapor; due to pressure difference, moves in the same direction as the heat flow and passes through the pores of the building element trying to reach the external environment.

During this passage of water vapor through the building element, if it comes into contact with a saturated or lower temperature surface, part of the vapor condenses into water. Accumulating within building elements, it damages building comfort. Condensation can occur on the internal surface or within building elements. For this reason, when designing building elements, calculations specified in TS. 825 and condensation control must be performed[9]. Plasters are deteriorating due to condensation problems in the walls of a building without thermal insulation located in the 3rd climate zone (Figure 13). An uncomfortable environment is provided to building occupants and more fuel consumption causes environmental pollution, thus harming both the economy of those living in the building and the economy of our country, which is dependent on foreign energy sources. In applications where thermal insulation material was not considered in the design of building elements, energy loss and condensation problems were identified. Thermally insulated and uninsulated wall cross-sections, temperature, saturated vapor pressure and actual vapor pressure graphs are provided in Figure 14. In sections "A" and "B", what should be the minimum thickness of thermal insulation material (dyalitim=?) when using uninsulated building elements on external walls and internal plaster (lime+cement) (0.02 m), brick wall (0.19 m), thermal insulation material EPS (dyalitim=?), external plaster (lime+cement) (0.03 m)? When investigated, dyalitim should not be below 0.05 m. In sections "C" and "E", when using uninsulated building elements and what should be the minimum thickness of thermal insulation material when using internal plaster (lime+cement) (0.02 m), reinforced concrete shear wall (reinforced) (0.20 m), thermal insulation material EPS (dyalitim=?), adhesive mortar (lime+cement) (0.03 m), artificial stone cladding (ceramic mosaic) (0.006 m)? When investigated, dyalitim should be 0.06 m. In sections "D" and "F", when using uninsulated building elements and what should be the minimum thickness of thermal insulation material when using internal plaster (lime+cement) (0.02 m), reinforced concrete beam (reinforced) (0.25 m), thermal insulation material EPS (dyalitim=?), external plaster (lime+cement) (0.03 m)? The thermal insulation material thickness should be minimum dyalitim= 0.06 m.

To reduce or eliminate condensation risk; the temperature distribution across the entire section of the building component must be above saturation temperature. For condensation to not occur at all, all temperatures within the building component must be higher than the saturation temperature of water vapor.

This can be achieved through protection of the building component from external climate conditions and thermal insulation applications on all surfaces of the building in contact with external air. Thus, building elements remain on the warm side of thermal insulation and by maintaining them above condensation temperature, the problem is solved. Due to moisture on the material surface caused by condensation, deterioration can occur in building materials. Peeling, swelling, rusting, and rotting can develop on the surface. The Building Energy Performance (BEP) Regulation that came into effect on 5 December 2009 covers many areas from the architectural structure of buildings, selection of heating systems, the contribution to the country's economy, and most importantly, creating a healthy environment. Most recently, according to TS 825 Building Thermal Insulation Rules Standard published in December 2013, buildings must be insulated. Construction permits will not be issued for buildings without energy performance certificates. Implementation of energy performance certificates began from 1 January 2011, and existing buildings must have Energy Performance Certificates by 2 May 2017[11].

4. Conclusion and Recommendations

Through thermal insulation in buildings and energy savings, reduction of heating and cooling costs contribute to individuals' economy and thus the country's economy. The research conducted showed that there are many buildings in our country constructed without thermal insulation. It is estimated that the proportion of buildings with thermal insulation is approximately 10%, while buildings without thermal insulation are 90%. With the "Building Thermal Insulation Rules" standard issued in 2013, insulation became mandatory during the construction of new buildings. Existing buildings will also have to be insulated according to results in the energy performance certificate. It has been observed that local administrations issuing occupancy permits after architectural projects are implemented cannot conduct sufficient inspection regarding the buildings' compliance with projects or whether they are insulated. It has been observed that uninsulated buildings consume energy resources more, more fossil fuel than necessary is consumed to heat buildings, and particularly in winter months air pollution increases and causes environmental problems. As an example, minimum thermal insulation material thicknesses for external walls of buildings being constructed or having been completed in the selected 3rd climate zone were calculated, and it was demonstrated through this study that thermal insulation material should be used in details. When condensation graphs of thermally insulated and uninsulated external wall cross-sections were drawn, the following conclusions were drawn from the findings: • In uninsulated external wall detail "A", condensation problems occurred in the cross-section using external plaster, brick wall (0.19 m), and internal plaster, and the temperature difference on the brick wall between summer and winter months was calculated to be approximately 35°C.

Due to the high temperature difference, problems also occur on the surfaces of cladding materials. Since the temperature difference between the interior environment and the interior wall surface is 7.6°C, sweating (condensation) will be observed on the surface.

• In externally thermally insulated external wall detail "B", no condensation problems occurred in the cross-section using external plaster, thermal insulation, brick wall (0.19 m), and internal plaster, and the temperature difference on the brick wall between summer and winter months was calculated to be approximately 13°C. Due to the low temperature difference, no problems and deterioration occur on cladding materials. Since the temperature difference between the interior environment and the interior wall surface is 2°C, no sweating will be observed on the surface and comfortable environments will be provided to building occupants. • In uninsulated external wall detail "C", condensation problems occurred in the cross-section using artificial stone cladding, external plaster, reinforced concrete shear wall (0.20 m), and internal plaster, and the temperature difference on the reinforced concrete shear wall between summer and winter months was calculated to be approximately 40°C. Due to the high temperature difference, problems also occur on the surfaces of cladding materials. Since the temperature difference between the interior environment and the interior wall surface is 15.5°C, sweating will occur on the surface and building users will live in a discomforting environment. • In uninsulated external wall detail "D", condensation problems occurred in the cross-section using external plaster, reinforced concrete beam (0.25 m), and internal plaster, and the temperature difference on the reinforced concrete beam between summer and winter months was calculated to be approximately 40°C. Due to the high temperature difference, problems also occur on the surfaces of cladding materials. Since the temperature difference between the interior environment and the interior wall surface is 15.5°C, sweating has occurred on the surface.

• In externally thermally insulated external wall detail "E", no condensation problems occurred in the cross-section using external plaster, thermal insulation, reinforced concrete shear wall (0.20 m), and internal plaster, and the temperature difference on the reinforced concrete shear wall between summer and winter months was calculated to be approximately 10°C.

Due to the low temperature difference, no problems and deterioration occur on cladding materials. Since the temperature difference between the interior environment and the interior wall surface is 1.3°C, no sweating will be observed on the surface and comfortable environments will be provided to building occupants. • In externally thermally insulated external wall detail "F", no condensation problems occurred in the cross-section using external plaster, thermal insulation, reinforced concrete beam (0.25 m), and internal plaster, and the temperature difference on the reinforced concrete beam between summer and winter months was calculated to be approximately 8°C. Due to the low temperature difference, no problems and deterioration occur on cladding materials. Since the temperature difference between the interior environment and the interior wall surface is 1.2°C, no sweating will be observed on the surface and comfortable environments will be provided to building occupants. Temperature graphs were drawn for uninsulated details, condensation problems in details were analyzed, and it was understood that energy savings can be achieved through thermal insulation and condensation problems encountered in details can be eliminated. It was concluded that these issues must definitely be conveyed to academics, sectoral fields, applicators, building owners, users, and local administrations. Measures to be taken for achieving energy savings through thermal insulation, reducing air pollution, and protecting ecological balance can be recommended as follows:

Building owners and users must be made aware of thermal insulation, and promotional information about the importance of thermal insulation must be provided through press, media, and communication tools. More effective information about the importance of thermal insulation and materials must be provided in universities.

Thermal insulation rules in buildings and related Turkish Standards should not be constantly changed, and figures should not be altered. These changes and alterations force building owners, architects, applicators, and users into continuous additional expenses. In addition to 1/50 scale projects in buildings, thermal insulation-related projects showing system cross-section, plans, and elevations must definitely be provided. In addition to this system cross-section, there must be point details. The system cross-section and point details should be original drawings suited to the building rather than compiled solutions gathered from the market. Original details showing the most appropriate solutions for each building should be drawn by architects. It has been observed that conscious applications by non-expert personnel result in energy waste instead of energy savings in buildings due to faulty workmanship. For this reason, applications must be made in accordance with architectural projects, carefully and error-free. Care must be taken to prevent the formation of thermal bridges in buildings. Building inspection regarding thermal insulation applications in buildings should be conducted more comprehensively. All buildings in our country, which purchases a large portion of energy and is dependent on foreign energy sources, must be constructed in accordance with architectural projects, thermal insulation standards, building energy performance regulations, with error-free point details, system cross-sections, and with perfect application at high quality.

Assoc. Prof. Dr. Nazım Koçu / Architecture Department Faculty of Fine Arts / Konya KTO. Karatay University Hatice Koçu / Student / Selçuklu Anadolu High School, Konya

References [1]. Aköz, F., Üstün, B., Çakır, Ö., (2001), "Effects of Thermal Insulation in Buildings on Energy Savings and Environmental Pollution", TMMOB, Mechanical Engineering Chamber, Insulation Congress, 23-25 March, Eskişehir. [2]. Altınışık, K., (2006), "Thermal Insulation" Nobel Publishing, 1st Edition, Publication No:954, Ankara. [3]. Çınar, K., Koçu, N., (1999), "Causes and Consequences of Air Pollution in Konya City", City Administration, Human and Environmental Problems Symposium 99, 17 February, p.624-632, Istanbul. [4]. Anonymous, TS. 825, (2013), "Thermal Insulation Rules for Buildings", Turkish Standards, Art. ICS 91.120.10, Ankara. [5]. Toydemir, N., Gürdal, E., Tanaçan, L., (2000), "Material in Building Element Design", Literatür Publications, First edition, July, p. 393, Istanbul. [6]. Akıncıtürk, N., (2001), "Investigation of the Positive Effects of Reducing Heat Loss in Buildings Through Insulation on Energy Consumption", TMMOB. Mechanical Engineers Chamber, Insulation Congress, 23-25 March, Eskişehir. [7]. Arıoğlu, N., (2009), "Material Selection Should Be Considered in the Design Phase", Insulation, Doğa Publishing, Year.14, Issue.80, September-October, p.42-43, Istanbul. [8]. Eriç, M., (1994), "Building Physics and Materials", Literatür Publications, 1st Edition, April, Istanbul. [9]. İşbilir, D., (2009), "Investigation of Thermal Insulation Applications and Problems in Buildings", S.Ü. Institute of Science. Master's Thesis (Unpublished), p.113, Konya. [10]. Koçu, N., Dereli, M., (2010). "Achieving Energy Savings and Problems Encountered in Details Through Thermal Insulation in External Walls", 5th National Roof Facade Symposium, Paper, Dokuz Eylül University Architecture Faculty, 15-16 April 2010, pp.247-256, Izmir. [11]. Ünlü, C., (2009), "Heating, Cooling, Ventilation, Air Conditioning, Fire and Sanitary Installation Journal", TTMD, Issue:64, November-December, pp.9-13. Ankara.