# 73710 - Building Physics and Indoor Environment

### Course Unit Page

• Teacher Massimo Garai

• Credits 9

• SSD ING-IND/11

• Teaching Mode Traditional lectures

• Language Italian

## 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 to deal with water vapour condensation in building structures at 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, J.M. Cimbala, R.H. Turner, Elementi di Fisica Tecnica, McGraw-Hill, Milano, 1a ed. (2017). (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. A tutor will be available, outside lesson hours, for explanations and exercises.

## Assessment methods

Two written tests (recommended) and a final oral examination.

Written tests "in itinere"

Each written test covers one of the two parts of the course: Thermodynamics; Heat Transfer.

Each written test permits to reach a maximum possible score of 30 points.

Each written test is passed with a minimum score of 18 points.

The written test scores are valid forever (no limit date).

Passing a written test means passing the corresponding part of the program. This part will not be asked again during the oral examination.

The partial scores from the three written tests are arithmetically averaged.

If the average score is in the range [18, 24], inclusive, then the average score, rounded to the nearest integer, can be recorded as the final score on the day of an oral examination, at student's request.

If the average score is greater than 24, the student may ask to have an oral examination to try to improve the final score.

The student who has skipped one or more written tests shall pass an equal number of written tests in a fixed amount of time on the day of the oral examination before the beginning of the oral examination.

For the written tests each student shall have a pen and a pocket calculator. Everything else is forbidden.

The written tests are held once per academic year, immediately after the end of the lesson cycle. The exact dates are agreed with the students of the same academic year.

Oral examination

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 shall answer to questions on principles and methods ("questions on theory") and questions oriented to solve a numerical problem like those discussed in classroom ("exercises"). This aims to verify the student's ability to apply the given tools to model a situation, calculate the results and interpret them.

## Teaching tools

PC projector, overhead projector.

## Links to further information

http://acustica.ing.unibo.it/indexfta.html

## Office hours

See the website of Massimo Garai