Air Conditioning, Refrigeration and Heat Pumps

The planned module aims on closing a gap in the education of future engineers working in the building sector. It will help to obtain a better understanding of the challenges in supplying buildings with Heating, Ventilation and Air Conditioning (HVAC) services.
The graduates will be able to draft an AC plant for a specific application and to perform a coarse design calculation.

Especially against the background of the new federal legislation on building energy technology and the constantly growing market for AC technology, the new module will give important insights into the thermodynamic principles and the operation of air conditioning and refrigeration plants. Heat pumps are of actual interest and will also be highlighted in the lecture. The outcome of the module will be a basic knowledge on the design and application of different AC systems and heat pumps.

The contents will be as follows:

0 Preview and Introduction
1 Gas-Vapour Mixtures
1.1 Thermodynamic Principles
1.1.1 Terms and Definitions
1.1.2 The Concept of Vapour Pressure
1.1.3 Humidity Parameters
1.2 State Variables of Humid Air
1.2.1 p-v-T Behaviour
1.2.2 Enthalpy
1.3 The Mollier h-x-Chart
1.4 Air Conditioning in the h-x-Chart
1.4.1 Saturation, Dew Point and Wet Bulb Temperature
1.4.2 AC Operations
1.4.3 Surface Interactions and Wet Bulb Depression
1.4.4 AC Regenerators
2 Set-Up and Operation of AC Systems
2.1 Central AC Units
2.2 Split and Portable Units
3 Introduction to Refrigeration and Heat Pumps
3.1 Terms and Definitions
3.2 Overview on Refrigeration and Heat Pump Processes
4 Mechanical Vapour Compression (MVC) Cycles
4.1 Fundamentals
4.1.1 Thermodynamic Principles
4.1.2 Refrigerants and their Environmental Impact
4.1.3 Refrigeration Charts: T-s- and log p-h-Diagram
4.2 Peculiarities of MVC Cycles
4.2.1 Standard Cycles: R134a, R290 and related
4.2.2 Alternative Cycles: NH3, CO2 and Water
4.3 Components
4.3.1 Compressor Types, Operation and Lubrication
4.3.2 Other Components: Heat Exchangers, Expansion Valves etc.
5 Sorption Chillers and Heat Pumps
5.1 Fundamentals 
5.2 Absorption Cycles
5.2.1 Set-Up and Operation
5.2.2 The h-xi-Chart
5.2.3 Common Refrigerants and Solvents
5.3 Adsorption Processes
5.3.1 Set-Up and Operation
5.3.2 Common Refrigerants and Sorbents
6 Alternative Techniques
6.1 Solar Heating and Cooling
6.1.1 Introduction
6.1.2 Solar Driven Compression Cycles
6.1.3 Solar Driven Sorption Cycles
6.2 Evaporative Cooling

Thermodynamics, Heat Transfer (alternatively: Heat- and Mass Transfer)
For newcomers from Architecture and Civil Engineering, the basics of Thermodynamics and Heat Transfer will be covered in a special Tutorial.

5 ECTS Credits:
Total Hours: 90
Contact Hours: 36
Self-study Hours: 54

Written Exam 90 minutes.
1st Part: Short Questions 45 Minutes – Closed Book
2nd Part: Calculation 45 Minutes – Given Formulary, Pocket Calculator

(1) Veith, H.; Schmidt, D.: Grundkurs Kältetechnik, VDE 2021, ISBN 978-3-8007-5240-9
(2) Casties, M.; Boiting, B.: Handbuch der Klimatechnik, VDE 2022, ISBN 978-3-8007-5526-4
(3) Baumgarth, S.; Hörner, B.: Handbuch der Klimatechnik, C.F. Müller Verlag, 2000, ISBN 978-3-7880-7577-4