MEM23142A
Determine psychrometric processes and system performance

This unit of competency covers the skills and knowledge required to identify psychrometric processes and determine system performance in a commercial building.

Application

The unit applies to technicians in enterprises designing, manufacturing, installing, servicing or maintaining heating, ventilation, air conditioning and refrigeration (HVAC/R) equipment.

The unit is suitable for people working as, supervisors, technicians and HVAC/R draftspersons, and those pursuing manufacturing engineering or related technical qualifications and careers.


Prerequisites

MEM23004A

Apply technical mathematics

MEM23006A

Apply fluid and thermodynamics principles in engineering


Elements and Performance Criteria

1

Review psychrometric processes

1.1

Obtain and implement work health and safety (WHS) and environmental requirements for a given work area

1.2

Apply knowledge of psychrometric processes to analytical solutions to HVAC/R systems according to enterprise procedures

1.3

Diagnose air temperature and humidity problems using psychrometric charts

1.4

Consult appropriate personnel to ensure that work is coordinated effectively with others

2

Analyse the psychrometric and system performance of HVAC/R systems

2.1

Determine plant/system capacity and airflow requirements for effects of coil bypass factor and apparatus dew point (ADP) and partial load control

2.2

Calculate dehumidified air quantity using both target superheat (TSH) and effective room sensible heat (ERSH) methods

2.3

Establish plant capacity and air flow rates for the system/building

2.4

Establish air side systems and determine system performance

2.5

Determine systemic performance parameters

2.6

Consult as required on any contingencies and unexpected situations and take appropriate action based on specifications, codes and standards, and enterprise procedures

3

Document and report on psychrometric and HVAC/R system performance

3.1

Evaluate solutions to psychrometric and system performance to determine their effectiveness

3.2

Report and document analysis, including details of all findings, calculations and assumptions, according to enterprise procedures

3.3

Prepare and justify recommendations for any required actions in relation to HVAC/R equipment

Required Skills

Required skills

Required skills include:

plotting the psychrometric performance of a given HVAC/R coil

calculating the psychrometric performance of the coil

calculating the psychrometric performance of HVAC/R spray equipment

calculating required plant capacity and airflow rates

determining the psychrometric performance of a HVAC/R system in operation, including partial load control

interpreting drawings and specifications

communicating effectively with others

working in teams with others

communicating technical and procedural requirements to others

dealing effectively with unexpected situations

Required knowledge

Required knowledge includes:

adiabatic/evaporative cooling

isothermal humidification

cooling and dehumidification with high latent load

cooling and dehumidification with all outdoor air

cooling and dehumidification with all outdoor air and with dehumidified air requirements less than supply air

cooling with evaporative humidification

spray processes to include cooling and dehumidification, cooling and humidification with heated spray water, heating and humidification:

partial load processes

reheat

bypass of return air and mix of return air and outside air:

variable air volume

variable coil effective surface temperature

analysis of cooling coil selection and performance

psychrometric analyses, formulae and charts

indirect evaporative coolers

analysis of cooling coil selection and performance

cooling tower characteristics

Evidence Required

The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Critical aspects for assessment and evidence required to demonstrate competency in this unit

Assessors must be satisfied that the candidate can competently and consistently:

implement WHS workplace procedures and practices, including the use of risk control measures

demonstrate essential knowledge and skills to determine psychrometric processes and system performance

demonstrate competency within a timeframe typically expected of the discipline, work function and industrial environment

demonstrate the ability to determine psychrometric processes and system performance consistently for commercial buildings. This includes determining the plant capacity and airflow rates for a building and the ability to analyse system ‘air side systems’ and determine system performance.

Context of and specific resources for assessment

This unit may be assessed on the job, off the job or a combination of both on and off the job. Where assessment occurs off the job, then an appropriate simulation must be used where the range of conditions reflects realistic workplace situations.

The competencies covered by this unit would be demonstrated by an individual working alone or as part of a team. The assessment environment should not disadvantage the candidate.

Method of assessment

Assessment must satisfy the endorsed Assessment Guidelines of the MEM05 Metal and Engineering Training Package.

Assessment methods must confirm consistency and accuracy of performance (over time and in a range of workplace relevant contexts) together with application of underpinning knowledge.

Assessment methods must be by direct observation of tasks and include questioning on underpinning knowledge to ensure correct interpretation and application.

Assessment may be applied under project-related conditions (real or simulated) and require evidence of process.

Assessment must confirm a reasonable inference that competency is not only able to be satisfied under the particular circumstance, but is able to be transferred to other circumstances.

Assessment may be in conjunction with assessment of other units of competency where required.

Guidance information for assessment

Assessment processes and techniques must be culturally appropriate and appropriate to the language and literacy capacity of the candidate and the work being performed.


Range Statement

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

WHS requirements

WHS requirements include:

legislation

protective equipment

material safety management systems

hazardous substances and dangerous goods code

local safe operation procedures

awards provisions

Environmental requirements

Environmental requirements include:

relevant legislation, regulations and codes

correct handling and disposal of liquid and solid waste

elimination or minimisation of gas, fume, vapour and smoke emissions, including fugitive emissions

dust elimination, minimisation and control

minimisation of energy and water use

elimination or control of excessive noise

use and recycling of refrigerants

Appropriate personnel

Appropriate personnel may include:

supervisor

leading hand

foreman

manager

engineer

technician

trainer

mentor

team member

customer

client

Systemic performance parameters

Systemic performance parameters may include:

coil characteristics

spray processes

Enterprise procedures

Enterprise procedures may include:

the use of tools and equipment

instructions, including job sheets, plans, drawings and designs

reporting and communication

manufacturer specifications

operational procedures

industry standards


Sectors

Unit sector

Engineering science


Employability Skills

This unit contains employability skills.


Licensing Information

No licensing, legislative, regulatory or certification requirements apply to this unit.