The document serves as an introductory lecture on Heating, Ventilation, Air Conditioning, and Refrigeration (HVAC) engineering, covering essential topics such as the basics of HVAC, the vapor compression cycle, and performance metrics like the energy efficiency ratio. It explains the processes involved in heating, cooling, ventilation, and refrigeration systems, along with relevant diagrams for understanding the vapor compression refrigeration system. The document outlines the key performance indicators and different cases for the vapor compression cycle, emphasizing the importance of efficiency in HVAC systems.

1. Prof.R.S.KOLHE
Prof. R.S. KOLHE
ME (HEAT POWER)
BE (MECHANICAL)
WELCOME TO
Heating, Ventilation, Air
Conditioning and Refrigeration
Engineering

2. Lecture No 01
Topics to be covered
• Basics of HVAC
• Vapour compression cycle (VCR)
• Performance of VCR
• Representation of VCR on P-H and T-S plane

3. BASICS OF HVAC
• H- Heating
• V- Ventilation
• AC- Air-conditioning

4. • HEATING : Designing the system for low
temperature climate ( cold climate)
• VENTILATION: It is the fresh air penetrated form
outside. It is a process of replacing air in
conditioning space by fresh air having high indoor
quality .
• REFRIGERATION : It is process of removing heat
from body or space so that its temperature first
reduce and then maintained at a temperature less
than surrounding.
• AIR CONDITIONING : Air-conditioning is the process
of treating air so as to control its temperature,
humidity, cleanliness( air quality) and distribution to
meet the requirements of the condition space.

5. Expectation From HVAC
• Cooling or Heating to control Temperature.
• Humidify or Dehumidify to control moisture
content.
• Filter to remove contaminants
• Ventilate to supply fresh high quality air .
• Circulate to regulate air motion .

6. Vapour Compression Cycle
• Compressor
• Condenser
• Expansion device
• Evaporator

7. Standard Vapour Compression
Refrigeration System (VCRS)
• Process 1-2: Isentropic
compression of saturated
vapour in compressor
• Process 2-3: Isobaric heat
rejection in condenser
• Process 3-4: Isenthalpic
expansion of saturated
liquid in expansion device
• Process 4-1: Isobaric heat
extraction in the
evaporator

8. Standard Vapour Compression
Refrigeration System (VCRS)

10. Pressure – Enthalpy (P-H) Diagram

11. T-v diagram for the heating process of water at a)
constant pressure and b) different pressure.

12. Pressure - Enthalpy Chart

13. Pressure – Enthalpy (P-H) Diagram

14. TEMP- ENTROPY (T-S) Diagram

15. PERFORMANCE OF VCC
• Refrigeration Effect= h1-h4
• Refrigeration capacity = m(h1-h4)
• Compressor work= (h2-h1)
• COP = (RE/WC)
COP =(h1-h4)/ (h2-h1))
• Heat Rejected in condenser: h2-h3

16. The equipment efficiency is given as EER or kW/TR
ENERGY EFFICIENCY RATIO (EER)
The Energy Efficiency Ratio (EER) of an HVAC cooling
device is the ratio of output cooling energy (BTU/h) to input
electrical energy (in watts) at a given operating point.
(EER)R =
kW/TR Use for large capacity equipment such as Chillers
H eat ro m o val ra te in W att
E n erg y In p u t in W att
R
kW /T R  =
P ow er in p u t (kW )
C ap acity (T R )

17. Different cases of vcc
case 1: Dry saturated vapour at Entry of the compressor

18. CASE 2: Refrigerant is Wet at Compressor Entry
• P-H Diagram • T-S Diagram

19. Case 3: Sub cooling or undercooling

20. Case 4: superheated vapour before compression

21. Have a good day
Thank you