Refrigeration Systems
Refrigeration Systems
Student Resource Package No: NR 18/19/20/45/46
(excluding 6)
Nominal Student Hours:
72 Hours.
Delivery:
Competence in this training program can be achieved
through either a formal education setting or in the
workplace environment.
Recognition of Prior
Learning:
The student/candidate may be granted recognition of
prior learning if the evidence presented is authentic and
valid which covers the content as laid out in this
package.
Package Purpose:
This package provides the student with the
underpinning knowledge to identify various types, of
domestic refrigeration and commercial refrigeration
systems together with their operational characteristics.
Suggested Resources:
Australian Refrigeration and Air Conditioning Vol
1&2.
Various Manufacturers Service and Installation
Manuals.
Assessment Strategy:
The assessment of this package is holistic in nature and
requires the demonstration of the knowledge and skills
identified in the student package content summary. To
be successful in this package the student must show
evidence of achievement in accordance with the
package
Competence:
This package should be supported by workplace
exposure to the various applications under the guidance
of a licensed mentor.
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Assessment:
Grade Code: 72
GRADE
CLASS MARK (%)
DISTINCTION
CREDIT
PASS
>=83
>=70
>=50
Assessment Events:
1.
Theory Test
Domestic Refrigeration
30%
2.
Theory Test
Coolrooms / Freezer Rooms
Merchandising Cabinets
40%
Beverage Dispensing Equipment
Total Marks:
30%
100%
3.
Theory Test
Theory Tests:
Short answer Questions / electrical drawings
This assessment covers the contents of this student resource package.
Content Summary:
Domestic Refrigeration (Refer to Stage 2 Student Resource Package)
Coolrooms & Freezer Room:
3
Merchandising Cabinets:
22
Beverage Dispensing Equipment:
36

Beverage Cooler (Temprite) systems and associated equipment:
36

Glycol Systems:
43

Ice Making Machines:
45

Postmix Refrigeration systems:
53
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Coolroom & Freezer Rooms
Section No: 2
Purpose: The purpose of this section is to provided you with the relevant knowledge and
skills in regards to food preservation
Food Preservation: (ARAC, page 1.5)
Refrigeration is the most widely used means of preserving food in its original fresh state.
Refrigeration involves the use of low temperature as a means of preservation of perishables
by eliminating or retarding the activity of spoilage agents.
The degree of temperature required to adequately preserve various fruits, vegetables and
meats varies with the length of time the product is to be stored.
Note: Product storage data table 1.2 ARAC page 1.9
HACCP
HACCP stands for Hazard Analysis Critical Control Point (and its pronounced hass-up).
HACCP emerged as a result of collaborative work between the Pillsbury Company, US
Army Natick Laboratories and the National Aeronautic and Space Administration (NASA).
A system for preventing food safety hazards was required for application to foods intended
for the space program. (Think about vomiting in a space suit.) The only alternative was end
product testing and, if certainty was to be assured, a 100% sampling rate would be required
leaving little or no products for the astronauts to eat. Process control emerged as a solution.
Since then, HACCP has been taken up by food companies around the world, to help control
the food production process. It is usually part of a wider quality assurance program.
Basically, a HACCP program means finding out where the really serious problems occur,
monitoring these steps so you know if there are problems, and fixing any problems that arise.
As for us, our responsibility is to ensure that our part of the process i.e. correct temperatures
and humidity’s are maintained at all times and that adequate monitoring and logging
procedures are in place.
Note: Product storage data table 1.2 ARAC page 1.9
Coolroom / Freezer Room Construction:
Modern refrigerated coolrooms / freezer rooms are constructed of rigid self supporting
Insulated panels. Both inner and outer skins are made form white powder coated steel
sheeting (colorbond). The insulation sandwiched between the inner and outer skins can be
either polystyrene foam (PSF) or polyurethane foam (PUF).
The panels are designed so that each panel slips into each other without the need of extruded
strips and are joined using a suitable sealant (mastic) and rivets. Kit type rooms are also
available and the panels are locked together by a cam lock system, using a large Allen key.
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Self supporting coolroom / freezer rooms
insulated panels
Insulation
Power coated steel sheet
on both sides approx
0.7mm thick
Thermal Conductivity:
Thermal conductivity is known as the k Factor of a material and is a measurement of the
rate at which heat will travel through a material that is 1 metre x 1 metre x 1 metre at a
temperature difference of 1 Kelvin (1k).
15°C
1m
1m
1m
16ºC
The K factor of a material = W/m.K (watts per metre Kelvin)
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Table 1
Insulating Material “k” Factor
Material
k Factor
Polyurethane
0.025 W/m.K
Polystyrene (0ºC)
0.032 W/m.K
Polystyrene (-18°C)
0.030 W/m.K
Fibreglass batt
0.035 W/m.K
brick
0.81 W/m.K
Concrete
1.44 W/m.K
U Factor:
The U factor is the overall coefficient of heat transmission in watts per square metre per
Kelvin.
To find the U factor of a material use:
U=
k
x
k factor of material
Thickness of material (in metres)
The U factor of a material is measured in W/m 2. K
(Watts per square metre Kelvin).
Example: 1
Determine the U factor of the following
 Construction of room 75mm polystyrene foam
 k factor 0.032 w/m.K
0.032
0.075
=
0.4267 W/m2. K.
Example: 2
Determine the U factor of the following
 Construction of room 100mm brick
 k factor 0.81 W/m.K
0.81
0.10
=
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8.1 W/m2.K.
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Room Temperature Wall Thickness
Room Temperature
Recommended Wall
U Factor
Thickness
75 mm (PSF)
0.426 W/m2.K
50mm (PUF)
0.50 W/m2.K
150mm (PSF)
0.20 W/m2.K
100mm (PUF)
0.25 W/m2.K
+ 2°C
- 20ºC
Determining the U Factor of a Composite Material
Often the floor and walls of a coolroom / freezer room are made of more then one material.
This is known as a composite wall or floor.
When installing a coolroom on a raised concrete floor it is common practice for a panel of
PSF to be placed in a recessed hole in the floor and a layer of concrete to be poured over it.
Note: drawing below.
PSF Insulation
Concrete Floor
Vapour Barrier
(Plastic sheet)
Recessed floor known as
“set down”. Heated floor
required if slab suspended.
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Concrete Structure
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Calculating the U factor of a Composite Material:
The following details relate to the calculation required to determine the U Factor of a
composite material:


X-Thickness of each material in metres
K- Factor of each material. W/mK
The following formula applies;
U=
X1
K1
1
+
X2 ……….etc
k2
U = total U Factor of the composite materials in W/m2.K
X = thickness of each of the individual components in metres
k = k factor of each individual component in W/m.K.
Where:
Example:
Calculate the overall U factor for a coolroom floor consisting of 75mm polyurethane foam
and 100mm of concrete.
1
0.075
0.025
+
0.10
1.44
1
3 + 0.069444
= 0.325 w/m2.K
Transmission Load:
Before obtaining plant and equipment for the installation of a coolroom or freezer room a
thorough transmission load and product load should be determined to ensure correct
refrigeration capacity and equipment selection.
To determine the transmission load (heat leakage) of a coolroom the following applies:
Formula:
Q = U x A x td
Where:
Q = heat leakage in watts or kW
U = overall U factor
A = complete outside area in metres square
Td = the temperature difference between the ambient
and the room operating temperatures.
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Determining the transmission load for the attached coolroom
3.2m2
Ambient 28ºC
3°C
4.2m2
2.5m2
Coolroom details:
The coolroom is constructed from 75mm polyurethane foam rigid panels.
Design operating temperatures of 3ºC with an ambient of 28°C.
Note: When determining the total transmission load you may have to do the floor
separately due to the temperature difference.
Step.1 Determine the outside surface area of the walls ane ceiling:
 2 x 2.5 x 3.2 = 16m2
 2 x 2.5 x 4.2 = 21m2
 2 x 3.2 x 4.2 = 26.88m2
Total area = 63.88 m2
Step.2
Determine the U factor of polyurethane foam:
 Table 1 k factor = 0.25w/mK
 U factor =
k factor of material
0.025 =
0.3333 w/m2.K
Thickness of material
0.075
Step.3
Determine the temperature difference:
 28°C - 3ºC = 25K
 td = 25K
Step.4
Determine the total transmission load from the gathered information above:



Q = U x A x td
Q = 0.3333 x 63.88 x 25
Q = 532.33 watts.
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Total Capacity for a Medium Temperature Coolroom (3°C)
Aim: To determine the refrigeration capacity for coolroom in accordance with the




following details:
Transmission load as above in step 4.
Product load
Product pull down temperature time
Air change load.
Determine the total refrigeration capacity for the above coolroom in accordance with the
following details:
 Transmission load 532.33 watts
 500 kg fresh beef entering at 34ºC and cooled down to 3°C.
 16 hours pull down time
 Specific heat capacity of fresh beef equals 3.22 kJ/kg/K above freezing.
 Temperature difference = 31K
Method:
Q = mass x specific heat x temperature difference
Q = 500 x 3.22 x 31
Q = 49910 kJ
The heat removed in kilojoules must be converted to kilowatts
kW (kJ/s) = kilojoules
3600(seconds/hr) x 16(hrs)
Product load = 49910
= 49910
= 0.866 kJ/s or 0.866 kW
3600 x 16
57600
Product load 0.866 kW + Transmission load 0.532 kW = 1.398 kW total load.
Note: It should also be noted that there are other factors that may have to be included in the
total heat load calculation for a particular coolroom or freezer room such as the air change,
evaporator fans, light loads, glass door inserts, people, forklifts and heat of transpiration.
If you require further details in the determination of transmission and product loads etc
this will be covered in more detail in the HVAC & Refrigeration Diploma Course No:290.
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Medium temperature coolroom
(3°C)
Forced draught cooler or
Induced draught cooler
FDC or IDC
Metering device
Liquid line
Medium temperature
coolroom with an average
room temperature = 3ºC
Liquid line
filter drier
Suction
line
Sight glass
Condensing
unit
Typical Coolroom/ freezer construction of a kit room, these rooms are purchased in kit
form and the polyurethane injected panels are locked together using a large Allen key.
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Electrical wiring diagram medium temperature coolroom
N
M
K1- 4
M
L1
L2
K1-1
K1-2
M
3~
K1-3
L3
K1
LP
O/
HP
L
L
L
S
V
tº
M
Evaporator Fan Motor
Medium temperature coolroom (3°C) incorporating a pump
down cycle.
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Note: The following two control circuit diagrams can also be used to control medium
temperature coolrooms.
A
N
K1
O/L
HP
LP
M
t°
A
N
K1
t°
LP
O/L
HP
M
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At this point you should be able to set all the controls on each of the above circuit to
maintain an average room temperature of 3ºC.
Example:
In the space provided below determine the thermostat, low and high control settings for a
medium temperature coolroom. The room is operating on R404A with an average room
temperature of 3°C, SST of -3°C and an outside ambient temperature of 36º.
SST = 457 kPa

Room thermostat:

Low pressure control:
Cut out = 2ºC
Average room temperature = 3ºC
Cut in = 4ºC
Cut out = 100 kPa
Cut in = 560 kPa = 3ºC
Please note that the above LP cut-in settings are designed to ensure that the evaporator
is defrosted prior to compressor re-starting. Lower cut-ins may be set if an alternative
form of defrosting i.e. timer is used.

High pressure control
Cut out = Ambient + 15 + 5 Safety factor
36 + 15 + 5 = 56ºC = 2525 kPa
Automatic or manual reset.
Freezer Rooms:
Low temperature freezer rooms operate at a much lower saturated suction temperature (SST)
than a medium temperature coolroom and for this reason they require regular defrosts.
Freezer rooms can normally operate with a SST of between -15ºC down to -35°C and
therefore require the following additional components:










Defrost timer
Defrost heater
Drain heater
High limit safety thermostat
Fan delay (low pressure control or thermostat)
Anti – sweat heater around door jamb and relief ports
Suction line accumulator
Oil Separator
Crankcase pressure regulating valve.
MOP TX valve
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Subject:
Electromechanical Defrost Timer:
The defrost timer activates the defrost cycle. This type of timer is driven by a synchronous
motor, geared down to 24 hour function and allows for a set number of defrosts and duration.
This can be adjusted by the technician to suit each individual application.
Most low temperature freezers have four defrost periods per day with a duration set at
approximately 25 minutes. The termination of the defrost cycle can either be from time,
temperature or pressure.
Types of Defrost Timers:
 Time initiated time termination
 Time initiated time or pressure termination
 Time initiated time or temperature termination
 Electronic Timers.(are replacing electromechanical defrost timers)
Defrost Heaters:
The defrost heaters are energised by the defrost timer and are required to remove the ice that
has accumulated on the evaporator. This is done by heating the evaporator coil and at the
same time raising refrigerant temperature.
Note: all the ice on the coil should be removed at approximately 8ºC.
Drain Heater
As the ice melts on the evaporator the drain heater keeps the water warm allowing it to flow
freely to the outside drain.
High Limit Safety Thermostat
The high limit safety thermostat is designed to de-energise the defrost and drain heaters if the
evaporator temperature rises above a predetermined thermostat setting
Usually set to close at approximately -10°C and open at around 14ºC.
Note this thermostat opens on rise (OOR) and closes on fall (COF).
Fan Delay Thermostat (Reverse Acting Low Pressure Control)
The reverse acting thermostat or low pressure control fan delay controls are designed to
delay the period before the evaporator fans start up and usually close at a SST of around
-10°C and open at 0ºC.
This type of control removes the possibility of hot air and water from being blown onto the
product on the completion of the defrost cycle.
Anti -Sweat Heaters
Small wattage heater fixed to the inside of the door jamb to prevent any moisture or ice
forming around the door. The floor at the door will have a threshold heater fitted if the
concrete floor is set down.
Suction Line Accumulator
Designed to collect excess liquid refrigerant and allows the compressor to draw vapour and
oil back.
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Crankcase Pressure Regulating Valve (CPRV)
At the completion of a defrost cycle the evaporator pressure can exceed 600 kPa and for this
reason a CPRV is installed in the suction just before the compressor and can be adjusted to
control the pressure of the vapour entering the compressor regardless of the evaporator and
suction line pressure. Installing the valve to close to the compressor may cause hunting.
CPRV adjustment is accomplished by fitting service gauges and a clamp on ampere meter
around one of the active wires at the compressor.
The valve is adjusted by increasing or decreasing the spring pressure until the full load
amperes of the compressor is between 90 & 100 % FLA. This must be done during
compressor start up following defrost.
Types of refrigerant:
The preferred refrigerants used for low temperature applications within the industry are
R404A / R507 A. However some systems may still have R502, R12 or R22.
Relief Ports
Some times referred to as explosion or implosion ports. These devices are inserted in the
freezer wall and used to balance the external and internal air pressures as to save the room
from being structurally damaged. They have hinged flaps internally and are heated. The
number and size increase proportionally with room volume.
Typical Cold room installation Showing IDC and weather proof lighting.
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Low Temperature Freezer Room
Forced draught cooler
FDC or Induced draught
cooler
Defrost timer
Low temperature freezer
room with an average room
temperature = -18ºC,
operating on R404A.
Metering device Reverse acting
LP fan delay
LP
DT
Suction line
accumulator
CPR valve
Heated drain must be
Trapped and Insulated.
Note: A relief port is installed in one of the walls of the freezer room to
balance any air pressure differences.
Cross-section of freezer room relief port
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Low Temperature Freezer Room Insulation Thicknesses (Australia)
Room Temperature
Polystyrene
Polyurethane
-10ºC to -20ºC
100-150 mm
75-100 mm
-20ºC to -35ºC
150-200 mm
100 mm to 150 mm
Note: If unsure about the type of panel thickness required for the application, consult the
manufactures.
Factors to consider when selecting panel thickness:
 Ambient temperature.
 Is room exposed to direct sunlight?
 Relative humidity.
 Span (distance between walls).
 Height of walls.
 Load bearing.
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Low Temperature Freezer Wiring Diagram
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Review Questions Section No: 2
Q.1
Name two types of insulation material used in the construction of coolrooms and
freezer rooms:
Q.2
What is meant by the terms transmission and product load:
Q.3
List four factors that determine the refrigeration capacity of a coolroom or freezer
room plant
Q.4
List four additional components that are required for a freezer room in comparison to
a medium temperature coolroom:
Q.5
List three types of defrost timers and their operation methods:
Q.6
What is the purpose of the drain heater on a freezer room?
Q.7
Describe the operation of a reverse acting low pressure control:
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Q.8
Why and where is an anti-sweat heater used?
Q.9
What is the purpose of a suction line accumulator?
Q.10 Describe how you would adjust a crankcase pressure regulator:
Q.11 A medium temperature coolroom operates on R134a at an average room temperature
of 3°C with an evaporator TD of 6K and an outside ambient of 36ºC. In the space
provided indicate the following control settings: (Note show all working).
Q.12

Room thermostat

Low pressure control

High Pressure control
A low temperature freezer room operates on R404A at a room temperature of -20°C
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With an outside ambient of 35ºC. In the space provided indicate the following
control
settings:

Room thermostat

Fan delay thermostat

High limit safety heater thermostat

Defrost timer (Time initiated time or pressure terminated)

Low pressure safety control

High pressure safety control.
Q.13 Describe the construction and operation of a relief port.
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
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Merchandising Cabinets
Section No: 3
Purpose: The purpose of this section is to provide you with the underpinning knowledge to
identify the various types of merchandising cabinets their application, construction and
operational characteristics.
Supermarket Merchandisers: (ARAC, page 7.10)
Supermarket merchandising cabinets have been constructed over the years to provide
customers with the opportunity of self service and the type of cabinets are as follows:



Multi-deck open display cases
Single deck, well type cases
Reach in cabinets
Multi – Deck Display Cases
The multi-deck display cases are used to refrigerate and display dairy produce, cheese and
cooked meats at a temperature of around 3ºC. The evaporator coil is usually installed in the
bottom of the cabinet with fans forcing air up and over the product. Note: evaporator fans
operate continuously.
A well directed air curtain is designed to keep cold air in the cabinet and reduce air spillage
to a minimum. These cases loose approx 60% of air circulated.
Most multi-deck display cases are designed with removable ends so as they can be connected
end to end to increase the length to meet the customer’s requirements.
Low front Type Multi-Deck dairy
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Single Deck Well Type Cases
The single deck case is designed as a meat, fruit or vegetable merchandiser and can also be
redesigned as a freezer in a single width or double. These cabinets have much less air
spillage than up right merchandisers because the cold air circulating is heavy and falls down
over the product.
Anti-sweat heaters are installed under the cabinet’s stainless steel rub rail to prevent water
from condensing on the rub rail and dropping onto the floor.
Denotes Air flow Evaporator
Light
Defrost heater
Drain
e
d lin
a
o
L
Evaporator fan
Single deck case
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K1-1
L1
K1-2
L2
M
K1-3
L3
N
M
K
1
HP
t°
LP
O/
LL
Defrost heater, if fitted
M
Most cabinets have a
number of evaporator
fan motors.
Cabinet ant-sweat
heater element
Note:

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Defrost timer time initiated time or pressure
termination.
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Multi-Deck Display Case
Piping Circuit Diagram
EPRV
LP/HP
Defrost
timer
DT
Suction line
accumulator
Denotes Air flow Evaporator
Light
dl
Loa
Defrost heater
Drain
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in e
Evaporator fan
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Low Temperature Merchandising Cabinet
Wide island freezer
Air delivery
Defrost heater
Drain
RACEWAY
Air return
Evaporator
Fan
It should be noted that the evaporator fans on these cabinets
operate continuously even through the defrost cycle. The
reason for this is to ensure that the supply and return air ducts
do not accumulate any ice which may restrict air flow and
reduce capacity.
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Electrical Wiring Circuit Low Temperature Case
K1-1
L1
K1-2
L2
M
K1-3
L3
N
M
K
1
HP
t°
O/
LP
L
Defrost heater
t°
Drain heater
High limit safety thermostat
close at approximately - 10°C
Open at 8°C
M
Isolator
Most cabinets have a
number of evaporator
fan motors.
Isolator
Cabinet ant-sweat
heater element
Note:


Defrost timer time initiated time and or pressure
termination.
Compressor has a belt driven drive motor.
Diagram
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Low Temperature Merchandising Cabinet
Piping Circuit Diagram
EPRV
CPRV
LP/HP
Defrost
timer
DT
Suction line
accumulator
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Oil separator
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Multi – Deck Display Case
Electrical wiring Diagram
K1-1
L1
K1-2
L2
M
K1-3
L3
N
M
K
1
HP
t°
LP
O/
LL
Defrost heater, if fitted
M
Most cabinets have a
number of evaporator
fan motors.
Cabinet ant-sweat
heater element
Note:

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Defrost timer time initiated time or pressure
termination.
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Piping Circuit Diagram
EPRV
LP/HP
Defrost
timer
DT
Suction line
accumulator
Cabinet Capacities: Freezers
The following details approximate cabinet ratings per length:
Length of
Cabinet
Type of Cabinet
Saturated
Evaporator
Temp
Store Conditions Store Conditions
A/C 24°C
Non / Air
60 % RH
32ºC 60% RH
Cabinet capacity Cabinet capacity
2448 mm (8 ft)
Single Island
- 35°C
1190 watts
1320 watts
3870 mm (12 ft)
Single Island
- 35°C
1780 watts
1980 watts
2448 mm (8 ft)
Rear wall
- 35°C
1190 watts
1320 watts
3870 mm (12 ft)
Rear wall
- 35°C
1780 watts
1980 watts
Thermostat
Cut in / cut out
-26°C / -22°C
-29°C / -25°C
-26°C / -22°C
-29°C / -25°C
Recommended Control Settings:
Type of cabinet
Refrigerant
LP cut / cut out
EPR valve
Frozen food
Ice cream
Frozen food
Ice cream
R22
R22
R404A
R404A
62kPa /158 kPa
36 kPa / 140 kPa
90 kPa / 185 kPa
70 kPa / 165 kPa
62 kPa
NA
110 kPa
NA
Note: Defrost timer has a maximum of 4 defrosts / 24 hours
Defrost duration of approximately 40 minutes.
Temperature over ride: 8°C.
Pressure over ride: 668 kPa for R404A and 540 kPa for R22.
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Reach in Merchandiser cabinets
Reach in merchandisers are available in self contained or remote units in a variety of
temperature ranges from medium temperature to low temperature applications. With the
majority using forced draught evaporators the location of the evaporator can either be at the
top or the bottom of the cabinet.
Low temperature freezer cabinets are automatic in operation and require a number of
defrosts per day to keep the evaporator clear of ice.
Reach in Merchandiser cabinet
3 degree Celsius to –25 degree Celsius
Adjustable shelves
Force draught evaporator
Glass
doors, may
be heated
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Problems associated with self –service reach-in cabinets are as follows:
 Placing stock above the load limit line
 Drain blockage due to poor house keeping (product spillage and unattached labels).
 Overloading cabinet with warm product.
 Cost of operation.
 Poor thermal hold over.
Cabinet temperatures, saturated evaporator temperatures and types of refrigerant for
various cabinets
Application
Cabinet
Temp
Refrigerant
Suction Temp
(SST)
Dairy multi-deck
3 to 5ºC
Freezer double width
-20ºC
R134a
R22
R404A
R407A
R507
R134a
R22
R404A
Reach in frozen food
-20ºC
R404A
R507
-25°C-32°C
Reach in ice cream
-25ºC
R404A
R507
-36°C
Meat merchandising
0ºC
-10°C
-4 to -10°C
-32°C to -36°C
Installation:
To ensure the correct installation procedures are implemented you should check with the
manufacturers requirements and site conditions in regards to the following factors,









Refrigeration capacity for each cabinet
Installation and location of each cabinet
Refrigeration components required
Supply and electrical control circuits
Correct adjustment of all controls.
Type of refrigerant.
Drainage requirements.
Site Access.
Weight of stocked cabinets.
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Control Circuits (Systems)
The majority of supermarket merchandising and display cabinets utilise computer-operated
systems where all the parameters are programmed in to provide automatic control and
feedback through an alarm system. Typical systems in use are: CPC, Phasefale and Danfoss.
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Review Questions Section No: 3
Q.1
List three different types of supermarket merchandising cabinets:
Q.2
Where is the evaporator normally located in a multi-deck display cabinet?
Q.3
Why do most multi-deck display cases have removable ends?
Q.4
Why do single well deck cases have less air spillage than upright merchandising
cases?
Q.5
Anti sweat heaters are installed under the cabinets rub rail for what reason?
Q.6
List three problems associated with self service cabinets:
Q.7
Explain why the evaporator fans in a low temperature island freezer cabinet operate
continuously:
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Q.8
What is the purpose of the air curtain on a Multi deck open Cabinet?
Q.9
List three common refrigerants that are used in dairy multi deck cabinets:
Q.10 Give five factors that should be taken into account prior to installing supermarket
equipment:
`
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Beverage Dispensing Equipment
Section No: 4
Purpose: the purpose of this section is to provide with the relevant knowledge and skills in
the application and operation of various beverage cooling systems and ice making systems
that are used in the presentation of beverages in the hotel, club and restaurant industries.
Beverage Coolers (Temprite) Reference (ARAC, pages 5.4 & 7.20)
Instantaneous beverage coolers (IBC) were one of the most familiar evaporators encountered
in hotels and clubs. Although single IBC are encountered large hotels or clubs may connect
as many as six IBC to the one condensing unit. In this situation two, three or more
condensing units may share the load of ten, fifteen or more IBC distributed throughout the
hotel or club so that the failure of one unit would not adversely effect the total number of
IBC’s and thus trading would continue virtually uninterrupted. IBC’s are fully flooded
evaporators. The liquid level is controlled by a low side float and needle and seat (cartridge).
Installation requirements of IBC’s:

Surge Tank: This tank or vessel should be installed above the suction line so that
the excess suction pressure but not oil can be contained in this component. The vessel
is sized in such a way that for every one kilowatt motor power it should
accommodate at least 50 litres (0.05m3). Its purpose is that by increasing the volume
of the suction line it absorbs suction line pressure line fluctuations and prevents the
condensing unit from short cycling.
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
Constant Pressure Valve (750 valve): This valve is fitted to each IBC to maintain a
constant SET above the freezing point of the beverage. The constant pressure valve is
similar to an EPR valve but far more accurate.
Example:
Standard strength beer freezes at approximately -2ºC.
Refrigerant 134a
SET = 202 kPa = 1°C
Refrigerant R22
SET = 413 kPa = 1°C
The adjustment is done by fitting a set of gauges to the inlet side of the EPRV
and adjusted to the selected minimum pressure / temperature required. The valve
bellows can be lubricated by the removal of an 1/8th BSP plug and the insertion of
refrigerant oil.
 Oil Separator: An oil separator must be fitted to any refrigeration system that has an
IBC so that the possibility of oil entering the evaporator of an IBC is reduced.
Accumulated oil in the evaporator of an IBC reduces the amount of refrigerant and
thus capacity.
The oil separator is installed between discharge line and condenser as close to the
compressor as possible and should be charged with the recommended oil before
installation. The oil return line from the separator and compressor should be as short as
possible.
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LP / HP Control Settings:
Low Pressure Control Setting:
Cut out:
Should be a reasonable low pressure to ensure a long off cycle
Example =
21 kPa (134a)
100kPa (R22)
High Pressure Control Setting:
Cut out:
Example = Ambient + TD + 5K safety factor
Ambient temperature = 35ºC
Saturated Condensing Temperature = 40°C
Temperature difference = 15K
Cut out =
Cut in =
35 + 15 + 5 = 50ºC = 1220 kPa for 134a
Can either be manual or automatic reset with a fixed
differential.
Electrical wiring diagram beverage cooling system
Condenser fans
N
M
K1- 4
M
L1
L2
K1-1
K1-2
M
3~
K1-3
L3
Compressor
K1
LP
O/
HP
L
L
L
S
V
Coolroom or bottle
Cabinet circuit
tº
M
Evaporator Fan Motor
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Refrigeration circuit diagram beverage cooling system
EPRV
Coolroom
Evaporator
IBC
1
Pressure
relief
IBC
2
Note: addition hand line
valves can be installed in
the suction and liquid line
manifolds for additional
bottle cabinets if required.
Beverage flows from the coolroom to
the IBC at 4°C. The temperature is
further reduced in the IBC to 2°C
where it is transferred via the beer tap
into a glass for consumption.
IBC
Surge tank
CO2 gas
cylinder and
regulator
Coolroom used to store
package beer and beer
kegs at around 7ºC.
Heater
Note: CO2 is used as the pressure to
force the beer from the kegs to the
glass.
Beer
Kegs
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Refrigeration Systems
Bottle Cabinets (Hotels / Clubs)
The following details a range of bottle cabinets that are used in clubs, hotels and restaurants
Low pressure
control
Forced draught evaporator (FDC)
Usually two or three fan motor.
LP
Liquid line
Suction line
solenoid valve
Under bar bottle cabinet
Control circuit diagram
N
A
S
L
S
V
LP
M
Evaporator fan motors
M
Cabinet light circuit
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Refrigeration Systems
Operation of under bar cabinet:
The under bar bottle cabinet is usually part of the complete beverage cooling system. This is
obtained by the addition of further suction and liquid line hand line valve connections on
each of the manifolds.
The cabinet temperature is controlled by the low pressure control which cycles the suction
line solenoid valve on the evaporators saturated refrigerant pressure temperature. Note:
evaporator fans operate continuously.
Temperature control: (Refrigerant R134a)
 Place a compound pressure gauge on the evaporator side of the suction line
solenoid valve.

Set the cabinet low pressure control to cut in at 3°C (225 kPa)

With the main condensing unit in operation place a thermometer in the return air
steam of the cabinet.

Adjust the low pressure control to cut out at approximately 2ºC.
With an evaporator temperature difference of around 6 K the cut out pressure
would equal 161 kPa (SET = -3°C.
Liquid line
solenoid valve
Forced draught evaporator (FDC)
Usually two of three fan motors.
Suction line
Under bar bottle cabinet
Temperature controlled by cycling a liquid line solenoid valve by a cabinet thermostat
which senses the return air or evaporator coil temperatures.
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Refrigeration Systems
Under Bar Bottle Cabinet
N
A
L
L
S
V
tº
Evaporator fan motors
M
M
Cabinet light circuit
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Refrigeration Systems
Glycol Systems
Glycol systems have become the most popular system and have been designed to replace
beverage cooling systems and are manufactured to fit into a standard glass rack.
The chiller plate is basically a plate heat exchanger has no moving parts and can chill two,
four or six beverages.
Each chiller plate is individually controlled by a digital thermostat which is adjustable to
suit the required application.
The DX evaporator is mounted within a glycol bath which includes a small agitator motor to
ensure an even glycol temperature. The temperature of the glycol bath is controlled by a
thermostat in series with a liquid line solenoid valve which feeds refrigerant to the TX valve
(this type of control relies on a pump down cycle).
Mix ratio of around 30% glycol and 70 % water and should be regularly checked with a
refractometer.
Note: To become competent with current glycol systems it may be necessary for
you to under take on the job workplace training under the guidance of a licensed
mentor, attend manufacturers and or suppliers training program on their
product range.
Water Duct Systems:
This system is used for large hotel installations. It uses a simple refrigeration system that
combines the chilling of beer in the keg room by IDC’s as well as continuously cooling the
beer as it flows through the dispensing tap, by using a chilled water heat exchanger.
The “water duct” is a simple heat exchanger that has the beer in a centre tube and chilled
water in the outer tube.
Beer
Water
Water Duct
One condensing unit is used for both the coolroom and chilled water. The chilled water tank
is simply a TX valve fed coil in an insulated tank filled with the circulating water.
The circulating pump must have the capacity to maintain water flow in all circuits during
peak loads. It runs continuously during trading hours.
The coolroom contains the kegs as well as the water tank and circulating pump.
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Refrigeration Systems
Typical Piping Diagram for Glycol Chiller Plate System
Beer font
The glycol and beer lines are
enclosed in 25mm of insulation
called a python.
Glycol lines
Chiller plate
heat exchanger
Circulating glycol
pump
Beer line
DX evaporator in
glycol bath
Beer kegs stored in
coolroom at 7ºC
Beer gas cylinder
and regulator
The above circuit represents a glycol system using one plate heat exchanger and beer line. In
the majority of hotels and clubs there are a number of different beers available and for that
reason the number of plate heat exchangers and fonts may have to be increased to meet the
consumers; needs.
Note: one chiller plate can have six different beer circuits
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Refrigeration Systems
Ice Making Machines
Reference (ARAC, page 4.18)
Self contained ice making machines can be split into two categories and they are as follows:
1. Ice FLAKE machines
2. Ice CUBE machines.
Each category has many sub-groups as many of these machines are grouped mainly by the
shape of the ice cube they dispense. It must also be noted that the machines are controlled
electronically, electro-mechanically or a combination of both
1.
Ice Flake Machines:
These machines continuously deliver an irregularly shaped ice flake and are
often referred as “crushers”or “flakers”.
This type of system relies on specially designed tubular evaporators into which a
slowly revolving auger with minimal wall clearance is fitted. The auger motor
power is around 300watts and the gearbox driving the auger may require heavy
duty gear box oil during routine service. The auger bearings should be replaced
approx every two years.
FLAKERS
OPERATING PRINCIPLES - REFRIGERANT
ACCUMULATOR
EVAPORATOR
CAPILLARY TUBE
COMPRESSOR
AIR COOLED
CONDENSER
DRIER
Figure .1.
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Refrigeration Systems
Flakers
OPERATING PRINCIPLES - WATER
PLASTIC
SPOUT
FLOAT VALVE
WATER SEAL
Figure .2.
FLAKERS
OPERATING PRINCIPLES - MECHANIC
TOP BEARING
PLASTIC
SPOUT
ICE BREAKER
AUGER
WATER SEAL
BOTTOM
BEARING
DRIVE MOTOR
COUPLING
GEAR
REDUCER
Figure .3.
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Refrigeration Systems
FLAKERS
Ice Being Forced Thru Breaker by Auger
After two-three
minutes the first
pieces of flakes ice
are discharged
through the spout
of the freezer
dropping down into
the storage bin.
Figure .4.
FLAKERS
COMPONENTS - MECHANICAL SYSTEM
•WATER SEAL
• AUGER
• ICE BREAKER
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Refrigeration Systems
Figure .5.
2.
Ice Cube Machines:
Ice cube machines are often given particular names based on the cube shape they
produce. This shape is determined by the design of the evaporator, water
circulation and harvesting methods. The most common types of ice makers
produce cubes by running or spraying water over an evaporator which is
manufactured to the shape of the cube required (see figure .9.). The evaporator
temperature, typically ranges from -6 degrees at the beginning of the freezing
cycle to -12 degree prior to harvest (defrost). Ice Cubers consist of two main
circuits the first being the refrigeration circuit and the second being the water
circuit.
Operation
Refrigeration Cycle (refer to figure 6)
During the refrigeration cycle and with the assistance of a compressor the warm
refrigerant vapour is remove from the evaporator and pumped to the condenser
under high pressure where it is transformed into a liquid. From the condenser the
refrigerant passes thru a filter drier and then onto the expansion device. The
expansion device will either be a thermostatic expansion valve or a capillary
tube. The liquid refrigerant the passes thru the expansion device and into the
evaporator. On entering the low pressure evaporator the high pressure liquid
vaporizes and absorbs the water travelling over the evaporator. This process
continues until sufficient ice has formed on the evaporator. For the machine to
know when the ice thickness is correct (and to initiate a defrost) several methods
are used.
Defrost initiation methods



Time and temperature. With this method a thermostat is attached to the
evaporator. Once the evaporator has reached a pre determine temperature
it supplies power to a defrost timer. The timer then times out for approx
15 minutes and then commences a defrost.
Water level. With this method an electronic control module look at the
level of the water in the water reservoir, it does this buy sensing earth
leakage thru probes positioned at different levels in the tank. Once the
level has dropped to the desired level the machine assumes that the water
has now been converted to ice and initiates a defrost.
Ice thickness sensors. There sensor are position on a bracket at a pre
determine distance, once the ice builds up on the evaporator and touches
the sensor the defrost is initiated. These sensors take the form of either a
mechanical thermostat type or an electronic type were to probes allow a
small current to pass between them once the ice hits them. An electronic
module senses the current and initiate a defrost.
Defrost Cycle (refer to figure 7)
Once the defrost cycle has been initiated a solenoid valve is energized. This
solenoid valve passes hot gas form the compressor directly into the evaporator.
This causes the evaporator to heat up, and any ice that has formed to fall away
from the evaporator and into a storage bin.
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Refrigeration Systems
Defrost termination
Defrost termination is either accomplished by the following methods,
 Thermostatically. This method employs a thermostat which is attached
the evaporator. Once the evaporator reached the desired temperature and
the ice has left the evaporator plate. The thermostat breaks the supply of
power to the hot gas solenoid and forces the system back into
refrigeration mode.
 Magnetic and Micro switches. (refer to figure 10) With the gravity
cascade type machines a hinged door covers the water cascade. During
the defrost cycle the ice falls of the plate and forces the hinged door
open as it falls into the bin. As the door opens it actives a micro switch
or magnetic switch which sends a signal to the electronic controller to
terminate the defrost and restart the refrigeration cycle.
Maintenance
All Machine require regular maintenance. Most manufacturers supply
recommended maintenance shedules. However water and air quality does
have a large bearing on the frequency of maintenance. Therefore each
installation should be evaluated seperately. With regardes to filtration, water
filter not more than 5 micron rating should be used.
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Refrigeration Systems
OPERATING PRINCIPLES - FREEZE
Evaporator
Hot
gas
valve
Air cooled
condenser
Compressor
Figure .6.
OPERATING PRINCIPLES - HARVEST
Evaporator
Hot
gas
valve
Air cooled
condenser
Compressor
Figure .7.
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MODULAR SERIES
FREEZING CYCLE
….
Figure .8.
MODULAR SERIES
FREEZING CYCLE
The machine remains in
the freezing cycle with the
ice that become thicker ….
Figure .9.
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Refrigeration Systems
OPERATING PRINCIPLES
In this picture the ice can
be seen forcing the
hinged door open. A
micro switch is attached
to the door. The switch
sends a signal to stop the
defrost. If the door stays
open i.e the bin is full
the machine will stop.
Figure .10.
MAINTENANCE
The most important program on the maintenance of the cuber
machines is the cleaning/sanitizing to be done on regular base as
detailed here below:
• Sanitizing:
Every month
• Cleaning:
Every six
On next slides will be shown the procedure for sanitizing and
cleaning.
Figure .11.
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Refrigeration Systems
Postmix Refrigeration Systems
(Reference to manufacturers catalogues)
Counter top refrigeration systems can be broken down into two categories. These are:
 Mechanical
 Ice-Cooled.
Mechanical Refrigeration:
The dispenser is mounted on the counter serve top and contains the refrigeration unit within
the dispenser. Inside this unit the refrigeration system develops an ice block inside a water
bath area it also contains stainless steel cooling coils for water, soda water and syrup. A
small agitator motor runs continuously and assists in the efficient removal of heat from the
product coils and carbonator tank.
To carbonate the soda water a carbonator is installed inside the water bath to maintain
maximum carbonation. Note with exception to the ice bin type where the carbonator is
positioned outside the storage bin area either in the base of the unit or directly
Under the counter.
The syrup is supplied to the dispenser by stainless steel CO2 driven diaphragm pumps and a
bag in box package.
The water filter should be positioned as close to the unit as possible and accessible at all
times.
The syrup ratio or brix:
The taste of the finished product is dependent on the correct ratio of soda water to syrup.
This can be checked by using a syrup separator to separate the syrup from the soda water or
plain water at the dispensing valve. Or commonly a refractometer is used.
A ratio cup is used to measure the two products and has two chambers calibrated in mls or
cc’s.
Adjustment of the syrup ratio is done by adjusting the soda water first. The soda water
adjustment screw is on the left hand side of the faucet and should be adjusted for a nominal
flow of 5 ounces of water in three seconds. Once the soda flow rate is set the syrup can be
adjusted as per the correct ratio that is found on the Bag in Box.
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Typical Countertop Dispensing Refrigeration System
Coola Cola
Water
Filter
Syrup Boxes
10Kg
CO2
Bottle
1000mm
Ice – Cooled
This type of dispenser consists of a stainless steel storage bin with an aluminium plate that
has stainless steel cooling coils, the soda water, clean water and syrup cooling cast into it. Ice
fills the storage bin and acts as a refrigeration medium to cool the product passing through
the coils. This ice can be supplied by an ice maker fitted to the dispenser or from an outside
source.
The carbonator is positioned outside the storage bin either in the base of the unit or directly
under the counter.
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Refrigeration Systems
Typical Ice-Cooled Dispensing System
Coola Cola
Ice bin
Water
Filter
Water Pump
& Carbonator
10Kg
CO2
Bottle
1000mm
Syrup Boxes
Remote Syrup
boxes
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Review Questions Section No: 4
Q.1
Describe the purpose of the surge drum when used within a beverage cooling system:
Q.2
State the main purpose of a constant pressure valve (750 valve) and why is it used in
preference to an EPR valve:
Q.3
Why must an oil separator be installed in an instantaneous beverage cooler (IBC)?
Q.4
Name two methods of controlling the cabinet temperature of under bar bottle
cabinets:
Q.5
Describe in your own words the main advantage of a glycol system in comparison to
a beverage cooling system (IBC).
Q.6
State the major disadvantage of a Temprite (IBC) system?
Q.7
List two types of ice making machines and their major differences:
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Q.8
Describe two types of postmix refrigeration systems and their operational
characteristics:
Q.9
What does the term “brix” mean?
Q.10 In an ice-cooled counter top refrigeration system the ice can be provided by what two
means?
Q.11 Describe how you would adjust a beverage cooler (Temprite) to maintain a saturated
evaporator temperature of -1ºC:
Q.12 What drives the diaphragm pumps on a post mix refrigeration system?
Q.13 Why is it necessary for the compressor to operate during the harvest cycle on icecube machine?
Q.14 What type of evaporator is an IBC?
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Q.14 When adjusting the syrup ratio on a postmix dispenser what should be adjusted first?
Q.15
State the main purpose of the agitator motor in a postmix mechanical refrigeration
system:
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Saturated Pressure / Temperature Chart for Common Refrigerants
O
C
R12
kPa
R134a
kPa
R409a
kPa
R22
kPa
R502
kPa
R408a
kPa
R404a
kPa
R500
kPa
R717
kPa
-70
-89
-81
-74
-87
-90
-66
-85
-75
-67
-83
-87
-62
-81
-68
-57
-78
-82
-58
-76
-60
-46
-71
-76
-54
-69
-48
-34
-64
-69
-50
-62
-71
-37
-19
-23
-23
-55
-60
-46
-42
-38
-34
-30
-28
-26
-24
-22
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
-54
-43
-32
-18
-1
5
11
21
32
44
56
70
85
103
116
131
150
165
184
207
224
248
270
292
323
344
372
402
432
465
497
531
571
605
644
683
724
765
824
860
912
962
1010
1060
1118
1172
1236
1300
1362
1428
-63
-54
-43
-31
-16
-7
2
11
21
33
44
57
71
85
100
117
134
152
172
192
214
237
262
287
314
342
372
404
437
471
507
545
585
626
670
715
762
811
863
920
970
1030
1090
1150
1220
1290
1360
1430
1500
1580
-22
-6
10
32
63
80
91
106
126
145
165
185
207
231
254
284
310
334
361
396
430
465
504
542
584
622
668
716
769
814
866
917
975
1040
1107
1165
1230
1300
1378
1448
1525
1610
1688
1770
1855
1950
2050
2140
2245
2345
-2
16
41
70
98
115
132
151
171
191
214
235
260
284
313
340
369
400
435
470
508
547
586
620
668
718
767
810
860
910
967
1020
1080
1145
1207
1270
1340
1410
1482
1558
1644
1725
1807
1887
1977
2070
2165
2265
2378
2475
-8
11
34
60
89
105
123
141
161
181
203
227
251
277
305
334
364
396
430
465
502
541
582
625
670
716
765
816
869
920
980
1040
1100
1170
1240
1310
1380
1460
1530
1610
1700
1790
1880
1970
2060
2160
2270
2370
2480
2590
-6
15
39
66
97
114
133
152
173
195
219
243
270
297
326
357
390
424
460
496
537
579
623
669
716
766
819
873
929
989
1049
1119
1179
1249
1329
1399
1479
1559
1639
1729
1819
1909
2009
2109
2209
2319
2429
2549
2659
2789
-44
-33
-18
-3
16
35
45
54
65
76
87
100
118
134
156
174
193
215
239
262
285
314
340
367
398
422
454
490
530
569
610
651
695
740
785
832
875
925
980
1038
1098
1155
1215
1278
1348
1420
1489
1560
1635
1714
-50
-37
-22
-4
18
30
46
60
76
89
105
124
145
165
190
215
241
269
299
328
362
397
433
473
513
555
605
654
704
755
811
868
930
995
1065
1130
1203
1277
1369
1449
1543
1630
1722
1820
1914
2005
2110
2229
2366
2515
Refrigeration Systems
-64
-55
-45
-32
-17
-9
0.3
10
20
31
43
56
69
84
99
115
133
151
171
191
213
236
260
286
313
341
371
402
434
469
505
543
582
623
666
711
758
807
858
911
966
1024
1063
1145
1210
1277
1347
1419
1494
1571
Compiled By: G Riach & R Baker
Ultimo 2005
59
Refrigeration Systems
Answers to Review Questions:
Section No: 2
Q1.
Polystyrene & Polyurethane.
Q.2
Heat leakage into the room & Heat removed from the product.
Q.3
Q.4

Transmission load

Product Load

Product pull down temperature time.

Air change load.
Defrost timer, Defrost timer, Drain heater, High limit safety thermostat, Fan delay,
Suction line accumulator, Oil separator, CPR Valve, Anti-sweat heater around door
jam and implosion port.
Q.5




Time initiated time termination
Time initiated time or pressure termination
Time initiated time or temperature termination
Electronic timers.
Q.6
To allow defrost water to drain freely and prevent it from freezing.
Q.7
The reverse acting low pressure fan delay control is designed to delay the evaporator
fan on start up to prevent the possibility of hot air and water blowing onto the product
on completion of the defrost cycle.
Q.8
Ant-sweat heaters are used to prevent moisture or ice forming around the door.
Q.9
Suction line accumulator collects excessive liquid refrigerant and allows the
compressor to draw it back as a vapour.
Q.10
CPR Valve adjustment is accomplished by fitting service gauges and a clamp on
ampere meter around one of the active wires at the compressor. The valve is adjusted
`by increasing or decreasing the spring pressure until the FLA amperes of the
compressor is between 90 and 100% FLA.
Refrigeration Systems
Compiled By: G Riach & R Baker
Ultimo 2005
60
Refrigeration Systems
Q.11
SET = 167 kPa
Cut out = 2ºC
Average room temperature = 3ºC
Cut in = 4ºC

Room thermostat:

Low pressure control:
Cut out = 100kPa
Cut in = 226 kPa = 3ºC

High pressure control
Cut out = Ambient + 15 + 5 Safety factor
36 + 15 + 5 = 56ºC = 1352 kPa
Automatic or manual reset.
Q.12. SET = -30ºC = 97 kPa.
Cut out = -21ºC
Average room temperature = - 20ºC
Cut in = -22ºC

Room thermostat:

Fan delay thermostat

High limit safety thermostat Cut out = 8ºC
Cut in = -10ºC

Defrost timer
4 defrosts per day each approx 40 minutes.
Pressure override 623kPa = 6ºC

Low pressure control
Cut out = 20 kPa
Cut in = 100 kPa

High pressure control
Cut out = Ambient + 15 + 5 Safety factor
35 + 15 + 5 = 55ºC = 2489 kPa
Automatic or manual reset.
Cut in = -10ºC
Cut out = 0ºC
Answers to Review Questions:
Section No: 3
Q.1

Multi deck display cases

Single deck well type cases

Reach in cabinets.
Refrigeration Systems
Compiled By: G Riach & R Baker
Ultimo 2005
61
Refrigeration Systems
Q.2
In the bottom of the cabinet
Q.3
So that they can be connected end to end
Q.4
Because the cold air circulating is heavy and falls down over the product.
Q.5
To prevent water from condensing on the rub rail and dropping onto the floor.
Q.6

Placing stock above the load limit line

Drain blockage due to poor house keeping

Overloading cabinet with warm product.
Q.7
So that supply and return air ducts do not accumulate any ice.
Q.8
To keep cold air in the cabinet and reduce air spillage to a minimum.
Q.9
R407A, R507, R134a.
Q.10

Refrigeration capacity of each cabinet

Installation and location of each cabinet

Refrigeration components required

Supply and electrical control circuits

Correct adjustment of all controls

Type of refrigerant.
Refrigeration Systems
Compiled By: G Riach & R Baker
Ultimo 2005
62
Refrigeration Systems
Answers to Review Questions:
Section No: 4
Q.1
By increasing the volume of the suction line the surge drum absorbs suction line
pressure fluctuations and prevents the condensing unit from short cycling
Q.2
Constant pressure valve is fitted to each IBC to maintain a constant SET above the
freezing point of the beverage. Constant pressure valve is similar to an EPR valve but
far more accurate.
Q.3
To reduce the possibility of oil entering the evaporator of an IBC.
Q.4


Low pressure control to cycle a suction line solenoid valve
Thermostat to cycle a liquid line solenoid valve.
Q.5
Uses much less refrigerant than an IBC and is manufactured to fit into a standard
glass rack
Q.6
Amount of refrigerant contained in the temprite.
Q.7


Ice flake machine, delivers irregularly shaped ice flake
Ice cube machine, delivers ice cubes.


Mechanical: contains a refrigeration unit within the dispenser.
Ice cooled: ice is contained in a storage bin and acts as the refrigeration
medium.
Q.8
Q.9
The syrup ration.
Q.10
By an ice maker fitted to the dispenser or from an outside source.
Q.11
Adjustment is done by fitting a set of gauges to the inlet side of the EPRvalve and
adjusted to the selected minimum pressure / temperature required.
Q.12
CO2 or Beer gas.
Q.13
Because the hot gas injected into the plate evaporator allows the ice slab to slide
down onto the cutting grid.
Q.14
Soda water flow rate has to be adjusted first.
Q.15
To assist in the efficient removal of heat from the product coils and carbonator tank.
Refrigeration Systems
Compiled By: G Riach & R Baker
Ultimo 2005
63