FISICA TECNICA E IMPIANTI

Knowledge and understanding

By the end of the course, students know and understand:

•      the principles of applied thermodynamics and their formulation for closed and open systems, direct and reverse cycles and the energy conversion systems derived from them (boilers, refrigerating machines, heat pumps);

•      heat transfer mechanisms — conduction, convection and radiation — and their combined action in the components of the building envelope;

•      the hygrothermal behaviour of the opaque and transparent envelope under both steady-state and dynamic conditions, together with the regulatory framework governing the related verifications;

•      the properties of moist air and the psychrometric processes underlying air-conditioning systems;

•      fluid flow regimes and the criteria for the layout and sizing of hydronic systems;

•      the fundamentals of lighting engineering: photometric quantities, light sources, daylighting and artificial lighting of indoor spaces;

•      the operating principles and the sizing criteria of solar thermal and photovoltaic systems;

•      thermal comfort assessment models — Fanger's approach for conditioned environments and the adaptive approach for free-running buildings — and the criteria for the assessment of visual comfort.

Applying knowledge and understanding

By the end of the course, students are able to:

•      set up and solve mass and energy balances for thermodynamic systems and for indoor environments;

•      calculate the summer and winter thermal load of a room and carry out the preliminary sizing of the main components of a heating, air-conditioning or hydronic system, including the pressure losses in the distribution networks;

•      assess the thermophysical performance of the opaque and transparent envelope and carry out the code-compliance checks concerning thermal transmittance, surface and interstitial condensation, thermal bridges and the performance of windows;

•      use psychrometric charts to represent moist-air processes and to quantify the sensible, latent and total loads involved;

•      carry out the preliminary sizing of a solar thermal system and of a photovoltaic system, from the estimation of the demand to the verification of the collector area and of the storage volume;

•      assess the thermal and visual comfort conditions of a space and relate them to architectural design choices in terms of orientation, envelope, shading devices and distribution of the openings.

Making judgements

Students acquire the ability to critically assess the results of the calculations they perform, recognising their order of magnitude and physical plausibility; to compare alternative envelope and system solutions, selecting the most appropriate one for the given climatic, functional and regulatory context; and to recognise the limits of validity of the simplified models adopted and the implications of the assumptions made. These abilities are developed through the applied numerical exercises, the guided discussion of the design cases presented during the lectures and the systematic comparison of the results with the limit values prescribed by the regulations in force.

From this perspective, the course contributes to the United Nations 2030 Agenda for Sustainable Development, addressing issues related to energy, to the energy efficiency of buildings and to the environmental impact of building technologies, in accordance with the following Sustainable Development Goals (SDGs):

•      SDG 4 — Quality education: students acquire knowledge that makes them aware of energy and environmental challenges, preparing them to devise innovative solutions in the building and technological field;

•      SDG 7 — Affordable and clean energy: through the study of heat pumps and of solar thermal and photovoltaic systems, the course trains students in the use of renewable energy technologies and in the energy efficiency of buildings;

•    SDG 11 — Sustainable cities and communities: the focus on air quality, hygrothermal well-being and the management of the energy demand of buildings prepares students to design sustainable and comfortable buildings, thus promoting more inclusive and resilient cities;

•    SDG 12 — Responsible consumption and production: students learn how to reduce energy consumption, limiting the environmental impact and promoting a sustainable use of resources;

•      SDG 13 — Climate action: the study of renewable energy systems provides the tools to promote solutions that are essential to the mitigation of climate change.

Communication skills

Students develop the ability to present, both in written and in oral form and with an appropriate command of technical language, the procedure followed and the results obtained, justifying the choices made; to use correctly the symbols, the units of the International System and the conventional graphical representations of the discipline (state diagrams, psychrometric charts, functional system layouts); and to interact with the other technical professionals involved in the building process on energy and building services matters. These skills are developed by requiring students to make explicit and to comment on the calculation steps in the exercises and in the written tests, through the classroom discussion of the assignments and through the supplementary oral examination.

Learning skills

Students acquire the ability to independently consult technical handbooks, sector standards and national energy legislation, updating their knowledge in line with regulatory and technological developments; to retrieve and interpret the thermophysical and climatic data required to solve a design problem; and to independently undertake the study of subsequent courses and professional activities in the fields of environmental design, building energy diagnosis and energy certification of buildings. These abilities are developed through individual study guided by the numbered bibliographic references recalled in the “Course planning” section and through the direct use of technical standards and calculation software during the exercise sessions.

The course comprises 82 teaching hours, of which 56 hours of lectures (Didattica Erogativa) and 26 hours of interactive teaching (Didattica Interattiva).

Lectures deal with the theoretical fundamentals of applied thermodynamics, heat transfer, environmental building physics and building services, and are mainly aimed at the achievement of the learning outcomes related to knowledge and understanding.

Interactive teaching takes the form of applied numerical exercises on the topics covered during the lectures — energy balances, system sizing, thermophysical verification of the envelope, psychrometric calculations — also with the aid of dedicated calculation software, and of the guided discussion of design cases. These activities are aimed at developing the ability to apply knowledge and understanding, as well as the transversal descriptors: the comparative analysis of alternative system and envelope solutions and the comparison of the results with the regulatory limit values contribute to making judgements; requiring students to present and justify the procedures they have followed contributes to communication skills; the independent use of technical standards, handbooks and climatic data contributes to learning skills.

If the course is delivered in blended or remote mode, appropriate adjustments may be made to the above, in order to ensure consistency with the syllabus.

Basic knowledge of general physics (in particular thermodynamics and fluid mechanics) and of mathematical analysis (differential and integral calculus) is fundamental; such knowledge is typically acquired in the first-year courses of the degree programme. It does not constitute a formal prerequisite, but it considerably facilitates the understanding of the topics covered.

Attendance of lessons is not compulsory; it is, however, strongly recommended. Active participation in the lessons fosters the acquisition of the specific disciplinary competences and the ability to integrate knowledge concerning new or unfamiliar topics, thanks also to the opportunity for a critical discussion of the topics covered, and promotes awareness in the learning process.

1. Thermodynamics

Units of measurement and the Zeroth Law of Thermodynamics. Thermodynamic systems. Extensive and intensive properties. Thermodynamic processes. State quantities and transfer quantities. Heat and work. Thermodynamic work for closed and open systems. First Law of Thermodynamics. State diagrams. Ideal and real gases. Incompressible fluids. Specific heat. Second Law of Thermodynamics. Direct Carnot cycle and entropy. Reverse Carnot cycle and irreversibility. Refrigerants. Heat pumps. Combustion and calorific value. Boilers.

2. Psychrometrics and air systems

Moist air. Characteristic psychrometric charts. Moist-air processes and air treatments in all-air conditioning systems. Sensible, latent and total heat. Calculation of the thermal load of a room. Layout of an air handling unit.

3. Fluid dynamics and water-based systems

Viscosity. Fluid flow regimes. Flow with friction and pressure losses. Layouts of hydronic systems and their components. Sizing of the system components. Calculation of distributed and localised pressure losses in distribution networks and ducts.

4. Heat transfer

Steady-state heat conduction in plane and cylindrical geometries. Steady-state convection for various geometrical configurations. Steady-state thermal radiation for various geometrical configurations. The black body and the radiative properties of real bodies.

5. Lighting engineering

Daylight and the physiology of vision. Photometric quantities and visual performance. Fundamentals of colorimetry. Light perception and visual comfort. Artificial light sources and artificial lighting systems. Indoor lighting design criteria. The average daylight factor and its verification criteria.

6. Solar thermal and photovoltaic systems

Calculation of the collected solar energy. Estimation of the domestic hot water demand. Estimation of the electricity demand. Calculation of the collector area and of the number of collectors/modules. Verification of the spacing between collectors/modules. Estimation of the storage volume. Components of a photovoltaic system. Design, installation and maintenance of a photovoltaic system.

7. Building thermophysics

Thermophysical properties of building materials. Steady-state thermal transmittance and thermal insulation. Summer thermal behaviour and dynamic thermal parameters. Code-compliance checks for the opaque envelope. Hygrothermal behaviour. Condensation and mould growth checks. Thermal bridges. The transparent envelope. Shading and solar control systems. Code-compliance checks for windows.

8. Thermal comfort

Environmental and subjective comfort variables. Fanger's theory for conditioned environments. The adaptive theory for free-running buildings.

1. Barney L. Capehart, Ph.D., CEM, Wayne C. Turner, Ph.D. PE, CEM, William J. Kennedy, Ph.D., PE, Guide to Energy Management, CRC Press
2. Yunus Cengel, Heat and Mass Transfer: Fundamentals and Applications McGrawhill
3. Duco Schreuder, Outdoor Lighting: Physics, Vision and Perception, Springer

The examination consists of a written test lasting approximately two hours, made up of 2 numerical exercises and 4 multiple-choice questions on the contents of the course; a total score of 18/30 is assigned to the exercises and a score of 8/30 to the multiple-choice questions. The test is passed with a mark of no less than 18/30.

Attending students, i.e. those who have attended at least 75% of the lessons, may sit two mid-term tests, each covering one part of the programme and structured according to the same format as the written test. Each test is passed with a mark of no less than 18/30; passing both tests allows students to register the examination with a mark equal to the average of the two tests, and in any case not higher than 26/30. The outcome of the mid-term tests remains valid until the end of the academic semester of reference.

Students who wish to improve the mark obtained in the written test or in the mid-term tests may sit a supplementary oral examination. The oral examination assesses in particular: the relevance of the answers with respect to the questions asked, the quality and the organic structure of the contents presented, the ability to establish connections between the different topics of the programme, the ability to provide applied examples and the command of technical language.

The final mark is awarded on the basis of the following parameters:

•      Examination not passed: the student does not possess the minimum required knowledge of the main contents of the course; the ability to use the specific technical language is poor or absent and the student is not able to set up calculation procedures independently.

•      Mark 18–21: the student possesses a minimum knowledge of the principles of thermodynamics, heat transfer and building services; calculation procedures are set up only with guidance, with a modest ability to critically analyse the results, and the topics are presented in a sufficiently clear manner although the command of language is poorly developed.

•      Mark 22–25: the student possesses a fair knowledge of the contents, although limited to the main topics; the required calculations are carried out independently and the results are interpreted in a not always linear manner, and the topics are presented fairly clearly and with a fair command of technical language.

•      Mark 26–28: the student possesses a good knowledge of the contents, solves applied problems independently, including complex ones, critically assesses the plausibility of the results and compares them with the regulatory requirements, and presents the topics clearly and with an appropriate technical language.

•      Mark 29–30 cum laude: the student possesses a thorough knowledge of the contents, critically integrates and connects the topics of the programme, promptly and correctly solves highly complex problems while justifying the design choices adopted, and demonstrates excellent communication skills and a full command of technical language.

Learning assessment may also be carried out on line, should the conditions require it.

To ensure equal opportunities and in compliance with current laws, interested students may request a personal interview in order to plan any compensatory and/or dispensatory measures based on educational objectives and specific needs. Students can also contact the CInAP (Centro per l'integrazione Attiva e Partecipata — Servizi per le Disabilità e/o i DSA) referring teacher within their department (https://www.cinap.unict.it/content/referenti).

1.     State the Second Law of Thermodynamics and derive the expression for the efficiency of the direct Carnot cycle, discussing its physical meaning.

2.     Describe the operation of a heat pump, define its COP and calculate its value for given temperatures of the cold source and of the hot sink.

3.     Determine the sensible and latent thermal load of a room of given dimensions, intended use and occupancy, under summer design conditions.

4.     Represent on the psychrometric chart the summer air treatment in an all-air system and calculate the thermal powers exchanged in each process.

5.     Calculate the distributed and localised pressure losses in a section of a distribution network of given geometry and flow rate, and select the commercial diameter of the pipe.

6.     Calculate the thermal transmittance of a multi-layer wall of given composition and verify its compliance with the limit values prescribed by law for the given climatic zone.

7.     Describe the phenomenon of interstitial condensation and carry out the Glaser verification for a given wall composition, commenting on the results.

8.     Define the average daylight factor, describe its calculation method and verify its value for a room of given dimensions and window area.

9.     Compare the main types of artificial light sources in terms of luminous efficacy, colour rendering and colour temperature, and describe the design criteria for the artificial lighting of an indoor space.

10.   Carry out the preliminary sizing of a solar thermal system for the production of domestic hot water serving a given user, determining the collector area, the number of collectors, the minimum spacing between rows and the storage volume.

11.   Describe the environmental and subjective variables involved in Fanger's model and define the meaning of the PMV and PPD indices.

12.   Describe the differences between Fanger's approach and the adaptive approach to thermal comfort, indicating their respective fields of application.