This unit involves the skills and knowledge required to design secondary refrigerant systems.

It includes designing secondary refrigerant systems based on a design brief and customer requirements, applying relevant industry standards, selecting components and documenting system design.

The skills and knowledge described in this unit may, in some jurisdictions, require a licence or permit to practice in the workplace subject to regulations for undertaking refrigeration and air conditioning work. Practice in the workplace and during training is also subject to work health and safety (WHS)/occupational health and safety (OHS) regulations.

No other licensing, legislative or certification requirements apply to this unit at the time of publication.

ELEMENTS

PERFORMANCE CRITERIA

Elements describe the essential outcomes.

Performance criteria describe the performance needed to demonstrate achievement of the element.

1

Prepare to design secondary refrigerant system

1.1

WHS/OHS requirements and workplace procedures for a given work area are identified, obtained and applied

1.2

Scope of the refrigeration system is determined from design specifications and/or in consultation with relevant person/s

1.3

Safety and system are identified, obtained and applied in accordance with relevant industry standards

1.4

Work supervisor and/or customer/s are consulted to determine functions and parameters of the system required in accordance with design specifications and workplace documentation

1.5

Design development work is planned in accordance with workplace procedures for timelines in consultation with others involved

2

Design secondary refrigerant systems

2.1

WHS/OHS risk control measures and workplace procedures for carrying out the work are followed

2.2

Relevant secondary refrigeration system analysis, components and piping are applied to developing the system design in accordance with workplace procedures and relevant industry standards

2.3

Safety, functionality and budgetary considerations are incorporated in the installation specifications

2.4

Equipment is selected in accordance with the design specifications and workplace procedures

2.5

Location of components is documented in accordance workplace procedures and operation of system functions

2.6

System design draft is checked in accordance with the design brief and relevant industry standards

2.7

System design is documented for submission to relevant person/s for approval

2.8

Unplanned events are dealt with in accordance with problem-solving techniques and workplace procedures

3

Obtain approval for engineering computer applications design

3.1

System design is presented to customer and/or relevant person/s in accordance with workplace procedures

3.2

Requests for alterations to the design are negotiated with relevant person/s in accordance with workplace procedures

3.3

Final design is documented and approval obtained from relevant person/s in accordance with workplace procedures

3.4

Quality of work is monitored in accordance with workplace procedures and relevant industry standards

Evidence required to demonstrate competence in this unit must be relevant to and satisfy all of the requirements of the elements, performance criteria and range of conditions on at least one occasion and include:

understanding required operating functions and parameters from the design specification

developing the design within the safety, regulatory and functional requirements and budget limitations

documenting and presenting design effectively

negotiating design alteration requests successfully

obtaining approval for final design

dealing with unplanned events

applying relevant work health and safety (WHS)/occupational health and safety (OHS) requirements, including using risk controls

designing secondary refrigeration systems

preparing to design secondary refrigeration systems.

Evidence required to demonstrate competence in this unit must be relevant to and satisfy all of the requirements of the elements, performance criteria and range of conditions and include knowledge of:

secondary refrigeration system design, components and piping design, safe working practices and relevant standards, codes and regulations, including:

technical standards, regulations and codes for secondary refrigeration systems:

environmental and safety considerations in the use and disposal of secondary refrigerants:

toxicity and food compatibility

flammability

environmental effects

safe disposal

safety data sheets (SDS)/material safety data sheet (MSDS) samples

registration requirements for transport and on-site use

secondary refrigeration systems design requirements:

applications of secondary refrigeration systems in refrigeration

introduction to secondary refrigeration

applications in industrial refrigeration: cold storage, food processing and climatic test chamber

application in commercial refrigeration: supermarkets and small commercial systems

advantages and disadvantages of secondary refrigerants over the direct use of primary refrigerants

properties, application and limitations of available secondary refrigerants:

general classification of secondary refrigerant types – single phase, volatile and phase change

general types of single phase secondary refrigerants available: glycols, alcohols, brines, hydrocarbons, silicone oils and water

common types of volatile and phase change secondary refrigerants available: CO2 and ice slurries

thermal and transport properties of most widely used single phase secondary refrigerants (MEG, PG, ethyl alcohol, CaCl2, potassium brines)

pump selection for viscous fluids

application concepts and principles:

main and loop circuits, use of variable speed pumps and overflow valves

buffer and storage tanks, benefits and disadvantages

loop temperature control and loop pump selection

control valve options: regulating and on/off, two-way and three-way, mixing and diverting

expansion and contraction of components, compensation for pipe expansion and effect of pipe pre-insulation

expansion and contraction of secondary refrigerant, use of membrane expansion tanks versus open expansion tank

air purging

secondary refrigeration system components and piping:

corrosion and material selection:

materials compatibility table

thermal and other properties of materials in use

pipe material and jointing methods/materials

pumps, impellers and seals

isolation and control valves

heat exchangers

pipe and insulation materials:

metal pipe

plastic pipe

post-installation insulation (in situ foaming, formed insulation and closed cell flexible insulation)

pre-insulated pipe material

vapour barrier – importance and maintenance

heat exchangers:

plate heat exchangers, brazed, welded, semi-welded and gasketed; design considerations in conjunction with primary refrigerant, flooded, direct expansion, and pump circulated primary refrigerant

shell and tube and plate and shell heat exchangers

fan coil units

system control:

primary pump speed and staging control

maintenance of minimum flow and control valve pressure head

overflow valves

secondary loop temperature control

room humidity and temperature control with fan-coil units

problem-solving techniques

relevant job safety assessments or risk mitigation processes

relevant manufacturer specifications

relevant WHS/OHS legislated requirements

relevant workplace budget, quality, policies and procedures

relevant workplace documentation.

Assessors must hold credentials specified within the Standards for Registered Training Organisations current at the time of assessment.

Assessment must satisfy the Principles of Assessment and Rules of Evidence and all regulatory requirements included within the Standards for Registered Training Organisations current at the time of assessment.

Assessment must occur in suitable workplace operational situations where it is appropriate to do so; where this is not appropriate, assessment must occur in simulated suitable workplace operational situations that replicate workplace conditions.

Assessment processes and techniques must be appropriate to the language, literacy and numeracy requirements of the work being performed and the needs of the candidate.

Resources for assessment must include access to:

a range of relevant exercises, case studies and/or simulations

relevant and appropriate materials, tools, facilities and equipment currently used in industry

applicable documentation, including workplace procedures, equipment specifications, regulations, codes of practice and operation manuals.

Foundation skills essential to performance are explicit in the performance criteria of this unit of competency.

Range is restricted to essential operating conditions and any other variables essential to the work environment.

Non-essential conditions may be found in the UEE Electrotechnology Training Package Companion Volume Implementation Guide.

Designing secondary refrigeration systems must include at least the following:

two of the following:

two multi-stage cascade, or

two liquid recirculation, or

one multi-stage and one liquid recirculation

major components, including:

heat exchanger

condenser

compressor

accumulator

pump

associated components and controls

Electrotechnology

Refrigeration and air-conditioning