Design of building's exterior walls has important influence on energy consumption, building cost and thermal comfort. It influences also heating and cooling devices size. Optimization of energy consumption of the building requires consideration of the building materials, their thickness and mass, type and thickness of insulation, and location of the insulation layer. The correct way to optimize all the above parameters is calculation of temperatures and energy consumption in dynamic process, which means considering changes every few seconds. This may be done only with computer program. It is not easy to gain expertise on such programs. In addition, submission of input values to the program is time consuming and frustrating process, which in many times ends with errors. This work analyses if the Thermal Time Constant method may be applied to determine energy quality of the building as an alternative to the dynamic simulation program. The Thermal Time Constant method is much easier, simpler and faster than computer dynamic simulation program. Few examples of exterior wall design were selected to calculate the energy consumption and room temperatures. Two locations were selected for the calculations, one with moderate summer and the second with moderate winter. The dedicated dynamic simulation computer program was applied to gain data regarding the energy consumption, maximum and average room temperatures for south facing room and for north facing room at each location. Thermal Time Constant reflects the thermal inertia and thermal mass of the building. Higher Thermal Time Constant (TTC) moderates the difference between day and night in the room, flattening the room temperatures extremes caused by ambient temperature and solar energy. Higher TTC is not necessary more expensive. To take advantage of high TTC is not so the question of additional investment, but the question of understanding the TTC concept. In some cases consideration of TTC caused changes to the building's design and construction technique, bringing benefits to the contractor, to the tenants and to the national economy. Disregarding TTC leads to wrong decisions, wrong design, waste of money for building's construction and increased energy consumption.

The design of a building's exterior walls has an important influence on energy consumption, building cost and thermal comfort. It influences also heating and cooling devices’ size. Optimization of energy consumption of the building requires consideration of the building materials, their thickness and mass, type and thickness of insulation, and location of the insulation layer. The correct way to optimize all the above parameters is a calculation of temperatures and energy consumption in a dynamic process, which means considering changes every few seconds. This may be done only with a computer program. It is not easy to gain expertise in such programs. In addition, submission of input values to the program is time consuming and frustrating process, which many times ends with errors. This work introduces the term “Thermal Time Constant” which may be applied to determine the thermal quality of the building as an alternative to the dynamic simulation program. The Thermal Time Constant method is much easier, simpler and faster than a computer dynamic simulation program. Higher Thermal Time Constant (TTC) moderates the difference between day and night in the room, flattening the room temperature extremes caused by ambient temperature and solar energy. Higher TTC is not necessary necessarily more expensive. To take advantage of high TTC is not so the question of additional investment, but the question of understanding the TTC concept. In some cases consideration of TTC caused changes to the building's design and construction technique, bringing benefits to the contractor, the tenants and the national economy. Disregarding TTC leads to wrong decisions, wrong design, waste of money on building construction and increased energy consumption.

A third or more of the energy consumption of industrialized countries is expended on creating acceptable thermal and lighting conditions in buildings. As a result, building heat transfer is keenly important to the design of buildings, and the resulting analytical theory forms the basis of most design procedures. Analytical Theory of Building Heat Transfer is the first comprehensive reference of its kind, a one-volume compilation of current findings on heat transfer relating to the thermal behavior of buildings, forming a logical basis for current design procedures.

The second volume targets practitioners and focuses on the process of green architecture by combining concepts and technologies with best practices for each integral design component

Thermal Time Constant (TTC) indicates the time required for change of 63.2% of temperature difference. This work develops useful application of TTC for determination of temperature change in buildings. Higher TTC results in slower change of room temperature, contributing to thermal comfort, to quality of the building and to energy conservation. The procedure developed in the work is for both purposes: to find the temperature change in the period of time and to find the period of time of specific temperature change.

Heating and Cooling of Buildings: Principles and Practice of Energy Efficient Design, Third Edition is structured to provide a rigorous and comprehensive technical foundation and coverage to all the various elements inherent in the design of energy efficient and green buildings. Along with numerous new and revised examples, design case studies, and homework problems, the third edition includes the HCB software along with its extensive website material, which contains a wealth of data to support design analysis and planning. Based around current codes and standards, the Third Edition explores the latest technologies that are central to design and operation of today’s buildings. It serves as an up-to-date technical resource for future designers, practitioners, and researchers wishing to acquire a firm scientific foundation for improving the design and performance of buildings and the comfort of their occupants. For engineering and architecture students in undergraduate/graduate classes, this comprehensive textbook: