The document discusses refrigeration and air conditioning systems. It provides information on various types of cooling systems including vapor-compression cycles used in refrigerators and air conditioners. It also discusses different refrigerants commonly used and covers the design and components of domestic, commercial, and transport refrigeration and air conditioning systems.

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4. The most commonly used method of cooling is with vapor-compression cycles, because it is fairly
easy to construct a cooling device employing this method and the cost is low. In fact, conventional
refrigerators use this method of cooling to keep your leftovers and drinks chilled! Air conditioners
also employ a vapor-compression cycle to cool the ambient air temperature in a room.
A working fluid (often called the refrigerant) is pushed through the system and
undergoes state changes (from liquid to gas and back).

5. Refrigeration is a process in which work is done to move heat from one location
to another.
Various fluids have been identified as
practical refrigerants. The most common
include ammonia, Freon (and other
chlorofluorocarbon refrigerants, aka CFCs),
and HFC-134a (a non-toxic hydro
fluorocarbon).
Power Consumption :
Cold Storage : 2000-5000 KW
Domestic Refrigerator : 100 – 250 KW

6. Domestic
Use
Commercial
Use
Transport
Purpose

7. Flow of Refrigeration Load
Calculation
Site Survey
Divide the site plan
Heat Load Calculation
Selection of Refrigeration equipment
 Pipe Design
Job: Design Ambient Temperature,
Storage Temperature and Humidity
Requirements, Dimensions, Insulation,
Type of Construction , Product.
The most important load for refrigeration
calculation is the Internal Load calculation
We have to choose different types of
cooling for non vegetarian as well as
vegetarian items.
The calculations will be different for those
two as well.

8.  The use of refrigerators in kitchens for storing
fruits and storing fish and meats safely for long
periods.
 Liquefying gases like Oxygen, Nitrogen,
Propane Methane etc.
 In oil refineries, chemical plants, and
petrochemical plants, refrigeration is used to
maintain certain processes at their needed low
temperatures.
 Metal workers use refrigeration to temper
steel and cutlery.
 In preservation of organic material.

9. Air Conditioning is the removal
of heat from indoor air for
thermal comfort. Air
Conditioner is the machine
which does this job.
Characteristics
 It is the mechanical way of regulating the temperature,
 Humidity control,
 Cleanliness,
 Air flow inside a room or a building.

10. Domestic
Use
Window A.C
Split A.C
Commercial
Use
Transport
Purpose

11. In Split AC Evaporator is indoors and Condenser is outdoors, connected by two
pipes. A package system on the other hand has everything in one unit, usually on
the roof but sometimes on the ground and ductwork is run to the conditioned
space.
A drawback of split portable units is that a
surface exterior to the building, such as a
balcony must be provided for the external
compressor unit to be located.
Most split system air conditioners
do not introduce outside air for
ventilation, and only perform a
temperature control function.

12. Windows Air Conditioners are one of the most widely used types of air conditioners
because they are the simplest form of the air conditioning systems.
The whole assembly of the window air
conditioner can be divided into two
compartments:
 The room side, which is also the cooling side
 The outdoor side from where the heat absorbed
by the room air is liberated to the atmosphere.
The base of Window Air
Conditioner is assembled inside
the casing which is fitted into the
wall or the window of the room in
which the air conditioner is fitted.

13. Central Air Conditioners incorporate two different coils in order to cool complexes. This
type of cooling system is used to cool the entire home, versus a window air conditioner
that is used to cool a specific area or room of your home.
 Chiller
 Air Handling Unit
 Ducts
 Grills
 Diffusers
 Insulation
 Centrifugal Pump

14. A Chiller is a machine that removes heat from a liquid via a vapour-compression
or absorption refrigeration cycle. This liquid can then be circulated through a heat
exchanger to cool air or equipment as required.
A typical chiller for air conditioning applications
is rated between 15 to 1500 tons (180,000 to
18,000,000 BTU/h or 53 to 5,300 kW) in cooling
capacity, and at least one company has a 2,700
ton chiller for special uses.
Chilled water temperatures can range
from 35 to 45 degrees Fahrenheit (1.5
to 7 degrees Celsius), depending upon
application requirements.

15. An Air Handling Unit (often abbreviated to AHU), is a device used to condition and
circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system.
An air handler is usually a large metal box
containing a blower, heating or cooling
elements, filter racks or chambers, sound
attenuators, and dampers. Air handlers
usually connect to a ductwork ventilation
system that distributes the conditioned air
through the building and returns it to the
AHU.
Small Air Handlers, for local use, are
called Terminal Units, and may only
include an air filter, coil, and blower; these
simple terminal units are called blower coils
or fan coil units.

16. A Diffuser is the mechanical device that is designed to control the
characteristics of a fluid at the entrance to a thermodynamic open system.
Diffusers are used to slow the fluid's
velocity and to enhance its mixing into the
surrounding fluid. In contrast, a nozzle is
often intended to increase the discharge
velocity and to direct the flow in one
particular direction.
The Diffusers which are
constructed in side-walls are
called Grill Diffusers.

17. The AC produces comfort conditions in which the human beings tend to feel
highly comfortable. In these conditions the working efficiency of the human
beings becomes maximum, hence they are able to work with greater vigour.
Here are some of the advantages of working
in an air conditioned environment:
 Efficiency of the human beings increases
 Better health
 Less noise
 Fresh air

18.  Domestic application
 Office buildings
 Bank
 Shopping complex
 Hotels
 Hospitals
 Restaurants
 Clubs
 Resorts
 Academic institutions
 Transport systems
 Defense
 Airports
 Aircrafts
 Ships
Various industries including but not
limited to
 Steel plants
 Power plants
 Textile industries
 Pharmaceutical industries
 Food processing and preservation
 Petro-chemical plants
 IT industries
 Telecom industries
 Electronic and printing media
 Clean rooms

19. Variable refrigeration flow (VRF) is a multi and direct expansion type air conditioning
system whereby one outdoor unit can be connected with multiples indoor units.

20. The term variable refrigerant flow
refers to the ability of the system to
control the amount of refrigerant
flowing to the multiple evaporators
(indoor units), enabling the use of
many evaporators of differing
capacities and configurations
connected to a single condensing
unit. The arrangement provides an
individualized comfort control, and
simultaneous heating and cooling in
different zones.
Currently widely applied in large
buildings especially in Japan and
Europe, these systems are just
starting to be introduced in the U.S.
The VRF technology/system was
developed and designed by Daikin
Industries, Japan who named and
protected the term variable
refrigerant volume (VRV) system so
other manufacturers use the term
VRF "variable refrigerant flow".

21. Comfort
Design Flexibility
With a higher efficiency and increased controllability, the VRF system
can help achieve a sustainable design. Unfortunately, the design of VRF
systems is more complicated and requires additional work compared to
designing a conventional direct expansion (DX) system.
Reduced Noise Levels
Flexible Installation Energy Efficiency

22. For a thorough calculation of the zones and whole-building loads, one of the following three
methods should be employed
 Transfer Function Method (TFM)
 Cooling Load Temperature Differential/Cooling Load Factors (CLTD/CLF)
 Total Equivalent Temperature Differential/Time-Averaging (TETD/TA)
According to Carrier Handbook for
HVACR Engineers, for the Coordinates of
the City of Kolkata, the highest load of
the year is obtained on 21st of May at
16.00 hrs.
We have used Carrier E20 form, which is
based on Instantaneous Peak Load
Method

24. Heat Load measures the
capacity of the space
heating system required to
maintain comfortable
indoor temperatures at any
one time, specified in Watts
per square metre of treated
floor area.
The heat load is determined by the
sub sequent steps:
 Calculating the areas separately
 Determining the number of
peoples and appliances
 Putting values in the sheet.

25. Psychometrics or psychometric or hygrometry
are terms used to describe the field of
engineering concerned with the determination
of physical and thermodynamic properties of
gas-vapor mixtures
Psychometric properties
Dry-bulb temperature (DBT)
Wet-bulb temperature
Relative humidity
Dew point temperature
Specific enthalpy
Specific volume

26. We have selected duct able split AC as it is a commercial application.
We have selected scroll
compressor based model for
better energy efficiency than
reciprocating compressors
from popular branded AC
Companies like Blue Star
Ltd, Voltas Ltd, Carrier AC
& RF Ltd.
We have seen that the
commercially available models
range from 5.5TR, 8.5TR,
11TR, 17TR*.
AS OUR HEAT LOAD IS 41 TR, WE HAVE SELECTED 4X11TR UNITS. i.e.
(4X11) = 44TR (10% extra as future provision)

28. Ducts are used in heating, ventilation, and air conditioning (HVAC) to deliver and
remove air.
Ducts can be made out of the following materials: Galvanized mild steel,
Polyurethane and Phenolic insulation panels (pre-insulated air ducts)

29. In industrial applications, commercially, duct designs are done through duct sizing
table in Carrier Handbook, Mechanical Ductulator, McQuay Duct Sizer Software
etc. Here, in our project, we have used McQuay Duct Sizer.
The chief requirements of an air
conditioning duct system are:
It should convey specified rates of air flow to
prescribed locations.
It should be economical in combined initial
cost, fan operating cost and cost of building
space.
It should not transmit or generate objectionable
noise.

30. The Duct Design is done in the sub sequent steps
 From Cooling Load & Psychometric Calculations, the required supply air flow rate is determined.
 From building layout and location of supply fan (IDU), the length of each duct run is determined.
 Suitable dimensions of the duct are selected after each air discharge.
The duct design methods
 Velocity Reduction Method
 Equal Friction Method
 Static Regain Method
Were we to break down the process
into its core components, this is what
a contractor would do when sizing
your duct work:
Determine CFM for Each
Friction Loss Rate
Duct Sizing

33. Insulation is essential in central AC plants as there are really long pipes and ducts
carrying cold water and air respectively. Without proper insulation the cold water and
air will gain from the surrounding.
Duct insulation is available in 1 and 2-inch thicknesses.
Outdoor Duct Insulation is comprised of two aluminium
foil facings, separated by a dual layer of polyethylene
bubble pack, glass wool, cotton etc
The main advantages of using glass wool are :
 Excellent thermal insulation,
 Unique lightness,
 Thin solution,
 Optimal acoustic performance,
 Active environmental protection,
 Cost effective solution.