Energy efficiency and building thermophysics
Learning outcomes of the course unit
The objectives of the course provide that each student acquires knowledge and skills related to the thermophysics of buildings. The course aims at providing the knowledge and skills (ie the ability to apply the knowledge) necessary for the thermal analysis of buildings and each of its sub-systems. To develop the necessary threshold skills required in the study of any building or plant component, the student is asked to demonstrate the achievement of knowledge and skills on the following aspects of particular importance.
1) To know the theories underlying the mathematical models of simulation of building and plant components.
2) To identify the critical points that can be improved, evaluate the uncertainties and tolerances inherent in each calculation method.
3) To analyze a building component (opaque or transparent structure, door or window) to check if it meets the transmittance requirements required by current legislation.
4) To identify the dominant parameters in the choice of a system or a component, define its shape, dimensions and peculiarities.
5) To know how to propose the appropriate design changes to increase the performance and energy efficiency of each system or component of the building-plant.
6) To identify the constraints imposed by the functional requirements and the characteristics of the materials.
7) To know the nomenclature and terminology, both scientific and normative, also in English.
At the end of the training activity, in agreement with the Dublin descriptors, the student must have acquired knowledge and understanding, independence of judgment, communication and display skills, ability to learn and communicate.
Basic knowledge of mathematics and physics.
Course contents summary
The contents cover all the physical and engineering aspects that allow us to face any problem in the building-plant system. First, the basic contents of heat transmission and fluid flow are introduced (conduction, convection, radiative transfer, mass and energy conservation equations, psychrometry). Then the concepts acquired for the thermal analysis of buildings are applied.
Fluid dynamics. Mass and energy conservation. Heat transfer. Conduction, laws and applications. Conevtive heat transfer, laws and applications. Radiative heat transfer, laws and applications. Solar radiation. Transmittance and global coefficient. The mean radiant temperature. H
Theory of heat exchangers. Radiators, fan coils, radiant panels. Windows (glass and frame) and doors. Blackout blinds and bins. Internal energy gains to the building. Solar gains through opaque and transparent components. Thermal bridges and linear trasmittance. Renewal of air, natural and forced ventilation. Heat loss from the building. Losses to the external air, to non-air-conditioned rooms, towards air-conditioned areas but at different temperatures, towards the ground. Radiative heat loss towards the sky. Transients in buildings. Attenuation and phase shift of the temperature wave. Energy requirements in buildings. Duration of the winter and summer air conditioning period. Ideal energy. The plants: emission, regulation, distribution, accumulation, generation. Heating power of the fuel. Primary energy. The air in the buildings. Dew temperature. Psychrometric diagram. Sensitble and latent load in buildings. Winter and summer air conditioning. Condensation in buildings. Surface condensation on cold interior walls. Interstitial condense; Glaser analysis.
Efficienza Energetica e Termofisica dell'Edificio, Esculapio Editore, Bologna, 2018, ISBN 978-88-9385-07-9.
Technical material provided by the teacher.
CFU 9, 72 hours in class (36 hours of lessons, 36 hours of practice). Teaching is the cognitive framework aimed at setting up, consolidating and evaluating to promote acquisitive processes. The teaching method includes lectures, Socratic heuristic lessons, case studies, exercises, cooperative learning, project work. All teaching material is readily available or uploaded to the Elly platform. The total study load for this teaching module is between 225 and 270 hours, ie between 25 and 30 hours per CFU. This includes the hours in class, the completion of the exercises, the study. Each student has the faculty, in full autonomy, to increase the hours of study. At the teaching time in class corresponds an equal number of hours of classroom exercises closely related to the lessons, during which the student is confronted with solutions to problems, or small projects to develop the ability to apply knowledge to real problems as they arise practically. The teacher explains the traces of development and solution on the blackboard. Continuous assistance is provided; the teacher is always available by appointment and provides assistance or advice by e-mail, at any time. The use of Excel or Matlab is recommended for the numerical solution of the exercises.
Assessment methods and criteria
There is only the final written exam, which ascertains the acquisition of knowledge and skills by conducting a test lasting 120 minutes, without the aid of notes, books or computer tools.
The written test consists of at least three problems, which span the entire course program, involving all the main topics. The answers require knowledge and application of skills. The questions correspond to the various parts of the chapters illustrated through the lessons and exercises. Each question allows to obtain an adequate score; the correct answer to each question allows to get the maximum grade (30 cum laude). Students receive detailed information on the correction criteria and receive extensive information to avoid interpretative misunderstandings regarding the comprehension of the text of the exercises.
The aim of the analytical graduation of the student's performance is the reliable and objective evaluation of the level of achievement of the expected learning outcomes.