General overview of HVAC Technology General overview of VRF Technology Benefits of VRF General overview of Refrigerant General overview of Ton General overview of Compressor

1. CIS Electricals Pvt. Ltd.
MD KHURSHID ALAM
M.TECH ENGINEER
Email- sm.arzoo111@gmail.com
Ph- +91 8750848018
HVAC- Presentation: HVAC Overview

2. General overview of HVAC
Technology
General overview of VRF
Technology
Benefits of VRF
General overview of Refrigerant
General overview of Ton
General overview of Compressor

3. INTRODUCTION:
Heating, ventilation, and air
conditioning (HVAC) is the
technology of indoor environmental
comfort. Its goal is to provide thermal
comfort and acceptable indoor air
quality.

4. What Is Air-Conditioning?
Air-Conditioning
Means
control of five parameter
First modern electrical air conditioning unit was invented by Willis Carrier in
1902 at Buffalo, New York

5. Total
Air-
conditioning
Solution
Air Movement
& circulation
Temperature
Control
Humidity
Control
Noise
Level
Indoor Air
Quality

6. Refrigeration Cycle:

7. Working of Refrigeration Cycle:
1. COMPRESSOR: There are two function of
compressor:
 Refrigerant flow create.
 Pressure difference create.
2. CONDENSOR: There are two function of
condenser:
 Release the heat of refrigerant.
 Convert vapor to liquid refrigerant.

8. Drier ( Receiver/Accumulator): Filtration of
refrigerant.
Silica Gel: Absorption of moisture.
3. EXPANSION DEVICE: Controls the amount
of refrigerant flow.
4. EVAPORATOR: There are two function of
evaporator:
 Absorption of heat energy.
 Convert liquid to vapor refrigerant.

9. Types of Air-Conditioning:
 Window Air-Conditioning System
 Split Air-Conditioning System
 Packaged Air-Conditioning System
 Central Air-Conditioning System

10. Window Air-Conditioning System:
 In this air conditioner all the components namely the
compressor, condenser ,expansion valve, evaporator and
cooling coil are enclosed in a single box
 Window air-conditioning system are one of the most
commonly used and cheapest type of air conditioners.
 Window air conditioner units are reliable and simple-to-
install solution to keep a room cool while avoiding the
costly construction of a central air system.
 Capacity up to 5 tons

12. Split Air-Conditioning system:
 The split air conditioner comprises of
two parts the outdoor unit and the
indoor unit.
 Outdoor unit consists of compressor,
condenser and expansion valve.
 Indoor unit consists of evaporator or
cooling coil and cooling fan.

14. Package Air-Conditioning System:
 They are used where the cooling loads extend
beyond 20 tons.
 All the components are housed in a same box.
 Cooled air is thrown by the high capacity
blower, and it flows through the duct laid
through various rooms.
 They are of two types PACS
i) air cooled ii) water cooled

16. Variable Refrigerant Flow (VRF) System:
 Variable refrigerant flow (VRF),
also known as variable refrigerant
volume (VRV), VRFs use
refrigerant as the cooling and
heating medium.

18. Heat Pump
versus
Heat pump with Heat Recovery

19. Heat Pump:

20. Outdoor
Unit
Indoor
Units
Controls
System
Heat Pump:

21. Heat Pump with Heat Recovery:
Simultaneous Cooling & Heating

22. Heat Pump with Heat Recovery:
Simultaneous Cooling & Heating
Branch
Circuit
Controller
Indoor
Units
Controls
System
Outdoor
Unit

23. Outdoor Unit:
 Controls compressor speed
 Controls condenser fan speed
 Controls pressure of refrigerant to maximize capacity
and efficiency

24. Branch Circuit (BC) Controller:
Separates refrigerant into gas and liquid
Ensures units in heating receive superheated gas
Ensures units in cooling receive sub-cooled liquid

25. Indoor Units:
Sense the space temperature
Contain a Linear Expansion Valve (LEV) that
automatically modulates
Allow the precise amount of refrigerant through the
heat exchanger
Filter and distributes air

26. Controls System:
Integrated sequence of operation
Takes input from the user and provides feedback to the
system

27. What are the benefits of VRF?
Two-pipe System
INVERTER Technology
Multiple Indoor Units
Variable Capacity System
Zoning System
Complete Control Offering

28. What Is Refrigerant:
Refrigerant is a fluid. Chemically use in cooling
machine.
Refrigerant Color Codes:
Number Type Picture Color Refrig. Name
R-22 HCFCs
hydrochlor
ofluorocarb
on
Light Green Monochlorodifluoro
methane
CHClF2

29. Number Type Picture Color Refrig. Name
R-134a HFCs
hydrofluor
ocarbons
Light Sky
Blue
Tetrafluoroethane
CH2FCF3
R-410A HFCs
hydrofluor
ocarbons
Rose R-32 + R-125
Difluoromethane
CH2F2 +CHF2CF3
R-407C HFCs
hydrofluor
ocarbons
Chocolate
Brown
R-32 + R-125 + R-134a
CH2F2 +CHF2CF3+CH2FCF3

30. Suction And Discharge Pressure Of
Refrigerant: PSI – Pounds per square inch
Refrigerant Suction
(PSIG)
Discharge
(PSIG)
Stand By
(PSIG)
R-22 60 265 150
R-134a 40 – 45 180 - 190 75 - 80
R-407 c 70 - 80 270 – 280 150
R-410A 100 - 110 380 – 400 220

31. Ton Of Refrigeration:
R
AC
1 TR
ICE
1 TR
AC
Ton of Refrigeration foot-pound-
second (fps) System:
1 Ton = 2000 (lb)
Latent heat of ice = 144 btu/lb
2000 x 144 = 2,88,000 btu/day
2,88,000/24 = 12000 btu/ hr
12000/60 = 200 btu/min
200/60 = 3.333 btu/sec
Note- 1 Tr = 12000 btu/sec

32. Ton of Refrigeration Meter,
Kilogram, Second, (MKS) System:
1 Ton = 907 kg
Latent heat of ice = 80 kcl/kg
907 x 80 = 72000 kcl
72000/ 24 = 3000 kcl/hr
3000/60 = 50 kcl/min
50/60 = 0.833 kcl/sec
Note- 1 kw = 0.24 kcl/sec

33. COMPRESSOR:
It is a heart of refrigeration system:
A Compressor is a device used to increase the
low pressure of air to High pressure.
Types of compressor:
 Reciprocating Compressor.
 Scroll Compressor.
 Screw Compressor.
 Centrifugal Compressor.

34. Reciprocating Compressor:
 The reciprocating compressor are slowly being
phased out because power consumption of 0.94 kw
per ton.
 There maintenance cost is high due to a large
number of moving parts.
Scroll Compressor:
 The scroll compressor are slowly replacing the
reciprocating compressor in capacity up to 40 tons.
 These compressor are more efficient requiring
approx. 0.75 kw per ton.
 They are maintenance free since they are rotary type
with minimum moving parts.

35. Screw compressor:
 These compressor are replacement for large size
reciprocating compressor and are available in much
large capacity then reciprocating unit.
 They have a high efficiency between 0.68 to 0.75 kw
per ton.
 The require minimum maintenance since there are less
moving parts.
Centrifugal compressor:
 These compressor are meant for large capacity between
200 tons to 2500 tons.
 They have the highest efficiency which can be as high as
0.62 kw per tons.

36. They require more maintenance then screw compressor
but are preferred for their large capacity range.
Motor Winding: (TERMINAL COVER)
 COMMON.
 STARTING.
 RUNNING.
Common
Starting Running

37. Continuity, Resistance(Ω) or winding
Testing:
Continuity is OK between common and starting terminal.
Continuity is OK between common and running terminal.
Continuity is OK between starting and running terminal.
Continuity is OK between starting and common terminal.
Continuity is OK between running and starting terminal.
Continuity is OK between running and common terminal.

38. Ground Testing:
Continuity is NOT OK between Common and Earth
terminal.
Continuity is NOT OK between Starting and Earth
terminal.
Continuity is NOT OK between Running and Earth
terminal.

39. Compressor testing:
Common
Starting Running
19.1 Ω63.2 Ω
82.7 Ω
Lowest valueMedium value
Highest value

40. Find out compressor motor terminal:
 Resistance is lowest between common and running.
 Resistance is Medium between common and starting.
 Resistance is Highest between starting and running.
Find out common:
Common
Starting Running
19.1 Ω63.2 Ω
82.7 Ω
CRCS
SR

41. To start compressor without relay:
Common
Starting
Running
Starting winding
Running winding
N
P

42. Check the quality of the broken comp.’s oil. the oil
has turn bad.
 Push out the bad oil inside the other compressors.
 Change the accumulator and oil separator
 Use high pressure nitrogen to purge the system and
 Then add necessary refrigerant oil.
 Vacuuming and add refrigerant.
Carbonized oil

44. Effect of poor maintenance on compressor power
consumption
Condition
Te
(0C)
Tc
(0C)
Refrigeration
Capacity* (TR)
Specific
Power
Consumption
(kW/TR)
Increase
kW/TR
(%)
Normal 7.2 40.5 17.0 0.69 -
Dirty condenser 7.2 46.1 15.6 0.84 20.4
Dirty evaporator 1.7 40.5 13.8 0.82 18.3
Dirty condenser
and evaporator
1.7 46.1 12.7 0.96 38.7

45. MAIN CAUSE OF COMPRESSOR FAILURE:
 Bad Vacuum.
 Moisture in compressor.
 Insufficient oil.
 Carbonized oil.
 Weak Capacitor.
 Terminal rusty.
 Loose connection.
 Low voltage.
 Low Refrigerant.
 High Refrigerant.
 Chocked Condenser.
 Low speed of Outdoor fan due to weak capacitor.

46. COPPER PIPE LEAKE PROBLEM:
 Due to not proper Brazing.
 Due to not proper tight of flaring point.
 Due to not proper insulation.
 Due to near carbon mono- oxide formation.
 Due to pinch.
 Due to not proper bend.
 Due to corrosion.
 Vibration at suction valve and discharge valve for this install rubber
pad at four side of the outdoor unit.

47. COPPER PIPE SIZING DETAILS:
TUBE OD WALL THICKNESS Temper
DesignPre
ssure
Weight
Working
Pressure
Inch mm mm swg (N/mm2) kg/mt (kg/cm2 or bar)
1/4" 6.35 0.80 21 soft 46.00 0.125 132.6
3/8" 9.53 0.80 21 soft 46.00 0.196 84.3
1/2" 12.7 0.80 21 soft 46.00 0.268 61.8
5/8" 15.88 0.99 19 soft 46.00 0.414 61.2
3/4", 6/8" 19.05 0.99 19 soft 46.00 0.507 51.0
3/4", 6/8" 19.05 0.80 21 Hard 72.50 0.410 63.6
7/8" 22.22 0.80 21 Hard 72.50 0.482 54.2
1" 25.4 0.88 20.5 Hard 72.50 0.607 52.0
1 1/8" 28.58 0.99 19 Hard 72.50 0.768 52.0
1 1/4" 31.75 1.10 18.5 Hard 72.50 0.948 52.0
1 3/8" 34.93 1.21 18 Hard 72.50 1.147 52.0
1 1/2" 38.1 1.32 17.5 Hard 72.50 1.365 52.0
1 5/8" 41.28 1.43 17 Hard 72.50 1.602 52.0

48. THANK YOU