HVAC Lecture by Sir kaleem

1. Air Conditioning and
Refrigeration
Course Code: Me 307
Credit hours: 03
Contact hours: 03

2. Introduction, history and
Applications of Refrigeration and Air
Conditioning
Lecture : 01

3. Refrigeration
The process of achieving and maintaining a
temperature lower than the surroundings at the
required level
 Refrigeration is a cooling process but a cooling
process is not necessarily a refrigeration process
Examples:

4. Air Conditioning
Air Conditioning is the treatment of air so as to
simultaneously control.
Temperature of air
Moisture content of air
Air quality
• Why we need to control these attributes of air?
Thermal comfort
Process control
Product requirements

5. Relation Between Refrigeration and Air
conditioning
REFRIGERATION AIR CONDITIONING
1. Only cooling is done in it
2. Only summer comfort is done in it in
addition to other applications
3. Refrigerator can be used for heating if
we operate it as a heat pump
1. In addition to cooling , heating
humidification, dehumidification etc is
done in it.
2. Human comfort for any season can be
done in it addition to other applications.
3. Air conditioner can also be used for
heating purposes in heat pump mode

6. Development in REFRIGERATION AND
AIR CONDITIONING
Development in Refrigeration can be divided
into groups
a) Natural Refrigeration
b) Artificial Refrigeration

7. Natural Refrigeration Methods
Refrigeration through Natural resources is known
as Natural Refrigeration.
A. Use of Natural Ice
1. Transported from colder regions
2. Stored the ice formed in winter season in ice
houses for summer use

8. Natural Refrigeration Methods
B. Refrigeration by Evaporative Cooling
C. Refrigeration by making salt solution

9. Limitation of Natural Refrigeration
1. Not user friendly
2. Do not provide reliable and continuous
refrigeration
3. Depend on local Condition
4. Uncertain due to dependence on
environment
5. Not available every where

10. Artificial Refrigeration
Refrigeration obtained through artificial ways is
known as artificial refrigeration.
William Cullen in 1775 demonstrated
experimentally that ice can be formed
artificially
To overcome the shortcoming of william
demonstration several studies were done to find
the way of recycling the refrigerant and different
cycles were developed

11. Vapor Compression Refrigeration Cycle
Oliver Evan in 1805 described the cycling of
vapor compression
In 1835 Jackob Perkins made the first vapor
compression Based Refrigeration setup
Limitations

12. Domestic Refrigerator
Domestic Refrigerator has its own history
 First natural ice base domestic Ice box was
used in 1803 for refrigeration purposes
Mechanical compressor based refrigerators
were developed in 1911 and nowadays we
used advanced version of it

13. Vapour Absorption Refrigeration
Systems
• In 1810 John Leslie demonstrated vapour
absorption experimentally
• Ferdinand card in 1860 develop first aqua
ammonia base vapour absorption system
• In 1878 Windhausan develop water H2SO4
vapour absorption system later on it was
replaced by LiBr

14. Vapour Absorption Refrigeration
Systems

15. Steam Jet Refrigeration System

16. Thermoelectric Refrigeration Systems
• In 1821 the German physicist T.J. Seebeck
invented a phenomenon and named it Seebeck
• In 1834, J. Peltier invented the reverse
phenomenon of Seebeck and named it Peltier
and freeze the water drop with it. He used
Antimony and Bismith for this purpose

17. Thermoelectric Refrigeration Systems

18. Applications of Refrigeration and Air
Conditioning
APPLICATIONS OF REFRIGERATION:
a) Food processing, preservation and
distribution
b) Chemical and process industries
c) Special Applications such as medical,
construction, ice skating etc
d) Comfort air-conditioning

19. Food processing, preservation and distribution
• Food preservation is one the most important application of
refrigeration
• Food can be preserved at low temperature for longer period
of time
Reason:

20. Storage condition for fruits and
vegetables

21. 2. Applications Refrigeration in
chemical and process industries
• Separation of gases
• Condensation of Gases
• Dehumidification of Air
• Storage as liquid at low pressure
• Removal of Heat of Reaction
• Cooling for preservation

22. Special Applications of Refrigeration
• Construction
• Desalination of Water
• Ice Manufacture
• Medical

23. Application of air conditioning
Air conditioning application can be divided
(a)Industrial air- conditioning and (b)comfort air-conditioning
Comfort air conditioning is already explained
(a)INDUSTRIAL AIR- CONDITIONING Applications:
Objective
 Provide favorable conditions for the process to be done in
efficient way
 Provide favorable conditions for the employees working in the
industry
1. Textile industry
2. Printing Presses

24. Industrial air conditioning applications
3. Pharmaceutical industries
4. Photographic Material
5. Farm Animals
6. Computer rooms
7. Power plants
8. Vehicular Air-conditioning