73710 - Building Physics and Indoor Environment

• Docente: Massimo Garai
• Credits: 9
• SSD: ING-IND/11
• Language: Italian
• Campus: Bologna
• Corso: Single cycle degree programme (LMCU) in Architecture and Building Engineering (cod. 0940)

Learning outcomes

The students will learn the principles of classical Thermodynamics and their extension to open systems. They will learn how to deal with simple thermodynamic systems. The students will be able to calculate the properties of atmospheric air, to work with its transformations and to apply them to HVAC systems.
The students will learn the basic mechanisms of Heat Transfer: conduction, convection and radiation. They will be able todeal with water vapour condensation in building structuresat a basic level. Focusing on engineering applications, they will be able to handle in the correct way practical problems of heat transfer and energy conversion.

Course contents

1. THERMODYNAMICS

1.1 Introduction.
Introduction to Thermodynamics. System of units.
Principle zero of Thermodynamics. Thermometry.

1.2 First and second principle.
First principle of Thermodynamics for closed systems.
Second principle of Thermodynamics for closed systems:
statement by Kelvin-Planck, Clausius and their equiv ale nce.
The Carnot machine.
Irreversibility of natural phenomena.
Entropy and lost work. Thermodynamic temperature.

1.3 Open systems.
Mass balance for open systems.
Energy balance for open systems.
Practical examples.
Pressure drop. The chimney formula.

1.4 Pure substances, diagrams and cycles.
p-v-T surface for pure substances. The Gibbs rule.
Saturated vapours. Thermodynamic diagrams.
Rankine cycle. Basic refrigeration cycle. Heat pumps.

1.5 Air and vapour mixtures.
Description of air and vapour mixtures. Psychrometric transformations.
Basics of environmental control.
Measurement of relative humidity.

2. HEAT TRANSFER

2.1 Conduction.
Fourier law. Fourier equation.
Steady state solutions: plane layer, cylindric layer.
Electric analogy and its limits.
Measurement of thermal conductivity.
Materials for the thermal insulation.

2.2 Convection.
Coefficient of convection.
Dimensional analysis and similarity.
Forced, natural and mixed convection.
Cooling by natural convection.
Dynamic and thermal boundary layer.

Basic definitions. Black and grey bodies.
Laws of Stefan-Boltzmann, Planck, Wien, Lambert, Kirchhoff.
Energy exchange between surfaces.

2.4 Combined heat transfer.
Global coefficient of heat transfer.
Heat exchangers.

2.5 Hygrometry
Water vapour balance in building stuctures.
Risk of condensation in building structures.
Glaser diagram.

Y.A. Çengel, Termodinamica e Trasmissione del calore, McGraw-Hill, Milano, 4a ed. (2016). (mandatory reading)

S. Lazzari, B. Pulvirenti, E. Rossi di Schio, Esercizi risolti di termodinamica, moto dei fluidi e termocinetica, Esculapio, Bologna (2004). (suggested for additional exercises)

V. Corrado, E. Fabrizio, Applicazioni di termofisica dell'edificio e climatizzazione, Ed. CLUT, Torino (2005). (suggested for additional exercises)

A. Magrini, L. Magnani, La progettazione degli impianti di climatizzazione negli edifici, Ed. EPC Libri, Roma, 2a ed. (2010). (suggested as a further reading on HVAC services)

Teaching methods

During the lessons all the contents of the course will be treated. The lessons will be complemented by numerical exercises, solved step by step, which are an essential part of the course.

Assessment methods

The exam is composed of preliminary written test and a subsequent oral part.

The written test always include the solution of a numerical problem like those shown during the lessons. This is useful to verify the student's ability to apply the learned methods and tools to modelize a given situation, calculate the results ad interpret their meaning.

Only the students who passed the written test are admitted to the subsequent oral part.

Students who did not pass the written test must try again the full exam (written and oral) in another date.

The questions aim to ascertain two main didactic objectives:

• the full knowledge of the theoretical concepts and methods presented to the classroom;
• the ability to use these tools to solve problems in the engineering field.

Students must prepare in advance their workplace for the on line exam, following the instructions available on the teacher's web site.

PC projector.