All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source. |
SOUTH AFRICAN QUALIFICATIONS AUTHORITY |
REGISTERED UNIT STANDARD THAT HAS PASSED THE END DATE: |
Determine the properties of air from a psychometric chart and carry out basic calculation involving heat and mass transfer |
SAQA US ID | UNIT STANDARD TITLE | |||
116695 | Determine the properties of air from a psychometric chart and carry out basic calculation involving heat and mass transfer | |||
ORIGINATOR | ||||
SGB Air-conditioning Refrigeration and Ventilation | ||||
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY | ||||
- | ||||
FIELD | SUBFIELD | |||
Field 06 - Manufacturing, Engineering and Technology | Manufacturing and Assembly | |||
ABET BAND | UNIT STANDARD TYPE | PRE-2009 NQF LEVEL | NQF LEVEL | CREDITS |
Undefined | Regular | Level 3 | NQF Level 03 | 7 |
REGISTRATION STATUS | REGISTRATION START DATE | REGISTRATION END DATE | SAQA DECISION NUMBER | |
Passed the End Date - Status was "Reregistered" |
2018-07-01 | 2023-06-30 | SAQA 06120/18 | |
LAST DATE FOR ENROLMENT | LAST DATE FOR ACHIEVEMENT | |||
2024-06-30 | 2027-06-30 |
In all of the tables in this document, both the pre-2009 NQF Level and the NQF Level is shown. In the text (purpose statements, qualification rules, etc), any references to NQF Levels are to the pre-2009 levels unless specifically stated otherwise. |
This unit standard replaces: |
US ID | Unit Standard Title | Pre-2009 NQF Level | NQF Level | Credits | Replacement Status |
9534 | Determine the properties of air from a psychometric chart and carry out basic calculation involving heat and mass transfer | Level 3 | NQF Level 03 | 7 |
PURPOSE OF THE UNIT STANDARD |
Calculate the amount of heat and water added to or removed from the air or the water flowing in an air-conditioning or refrigeration system. |
LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING |
Carry out simple calculations involving multiplications, divisions. Manipulating of simple formulas. Understanding of elementary thermodynamics. |
UNIT STANDARD RANGE |
Barometric pressure, Dry bulb temperature, wet bulb temperature, dew point temperature, relative humidity, vapour pressure, humidity ratio, enthalpy, density and specific volume. As supplied by National Metrology Laboratory (M&M Tek), Tel: 012-841-4623 03 012-841-2102. Density, specific heat capacity and specific latent heat of evaporation. |
Specific Outcomes and Assessment Criteria: |
SPECIFIC OUTCOME 1 |
Define "Psychrometrics", name and define the properties of air and plot an air condition on the psychrometric chart. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
The term "Psychrometrics" is defined. |
ASSESSMENT CRITERION 2 |
The composition of air is stated. |
ASSESSMENT CRITERION 3 |
The properties of the air are named and defined and their symbols stated. |
ASSESSMENT CRITERION 4 |
The psychrometric chart for the correct altitude and temperature range is selected. |
ASSESSMENT CRITERION 5 |
The state point for the condition given is plotted. |
ASSESSMENT CRITERION 6 |
The properties of the air are determined and recorded using the correct SI units and symbols |
SPECIFIC OUTCOME 2 |
Calculate the amount of sensible heat (in kilowatt) added to or removed from the air by means of the sensible heat formula and the enthalpy formula. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
The formulas required are stated. |
ASSESSMENT CRITERION 2 |
The mass flow of the air is calculated. |
ASSESSMENT CRITERION 3 |
The amount of sensible heat to be removed is calculated using the sensible heat formula. |
ASSESSMENT CRITERION 4 |
The amount of sensible heat to be removed is calculated using the enthalpy formula. |
SPECIFIC OUTCOME 3 |
Calculate the amount of sensible heat and latent heat and the total heat removed
(in kilowatt) added to or removed from the air by means of the enthalpy formulas. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
The formulas required are stated. |
ASSESSMENT CRITERION 2 |
The mass flow of the air is calculated. |
ASSESSMENT CRITERION 3 |
The amount of sensible heat removed is calculated using the enthalpy formula. |
ASSESSMENT CRITERION 4 |
The amount of latent heat removed is calculated using the enthalpy formula. |
ASSESSMENT CRITERION 5 |
The total amount of heat removed is calculated using the enthalpy formula. |
SPECIFIC OUTCOME 4 |
Calculate the amount of moisture added to or removed from the air. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
The formula required is stated. |
ASSESSMENT CRITERION 2 |
The amount of water added to or removed from the air is calculated in kilograms per second. |
ASSESSMENT CRITERION 3 |
The amount of water added to or removed from the air is calculated in litres per hour. |
ASSESSMENT CRITERION 4 |
Whether the moisture is added or removed from the air is stated. |
SPECIFIC OUTCOME 5 |
Calculate the amount of chilled water required for a cooling or heating application. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
The formula required is stated. |
ASSESSMENT CRITERION 2 |
The amount of chilled water required for cooling load is calculated. |
SPECIFIC OUTCOME 6 |
Calculate the amount of heat (in kilowatt) required to produce saturated steam. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
The formulas required are stated. |
ASSESSMENT CRITERION 2 |
The amount of heat required for the process is calculated in kilojoules. |
ASSESSMENT CRITERION 3 |
The amount of heat required for the process is calculated in kilowatt. |
UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS |
UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE |
UNIT STANDARD DEVELOPMENTAL OUTCOME |
N/A |
UNIT STANDARD LINKAGES |
N/A |
Critical Cross-field Outcomes (CCFO): |
UNIT STANDARD CCFO IDENTIFYING |
Identify and solve problems
Selecting the correct psychrometric chart and determining and using the correct parameters |
UNIT STANDARD CCFO COLLECTING |
Collect, analyse, organise and critically evaluate information
Using the correct information and selecting the correct formulas |
UNIT STANDARD CCFO COMMUNICATING |
Communicate effectively
Correctly report on results |
UNIT STANDARD CCFO SCIENCE |
Use science and technology effectively and critically
Use of psychrometric chart and psychrometric formulas |
UNIT STANDARD CCFO CONTRIBUTING |
Learner and societal development
Understanding the effect of adding or removing heat or moisture to or from the air |
UNIT STANDARD ASSESSOR CRITERIA |
N/A |
REREGISTRATION HISTORY |
As per the SAQA Board decision/s at that time, this unit standard was Reregistered in 2012; 2015. |
UNIT STANDARD NOTES |
This unit standard replaces unit standard 9534, which is "Determine the properties of air from a psychometric chart and carry out basic calculation involving heat and mass transfer", Level 3, 7 credits.
Supplementary information: One or two conditions of the air, together with the barometric pressure or the altitude to be indicated to the person being assessed (e.g. Barometric pressure or altitude plus WB and DB or DB and RH or DB and dew point Accuracy required: Dry bulb, wet bulb and dew point temperatures: ± 0,2K Relative humidity: ± 3% Humidity ratio: ± 0,0003 kg/kg Specific volume: ± 0,002 m³/kg Vapour pressure: ± 25 Pa Density: ± 0,1 kg/m³ Enthalpy: ± 0,2 kJ/kg Candidate is to be assessed without being led to the required response. |
QUALIFICATIONS UTILISING THIS UNIT STANDARD: |
ID | QUALIFICATION TITLE | PRE-2009 NQF LEVEL | NQF LEVEL | STATUS | END DATE | PRIMARY OR DELEGATED QA FUNCTIONARY | |
Elective | 48963 | National Certificate: Air-Conditioning, Refrigeration and Ventilation | Level 3 | NQF Level 03 | Passed the End Date - Status was "Reregistered" |
2009-03-12 | Was MERSETA until Last Date for Achievement |
Elective | 65509 | Further Education and Training Certificate: Air-conditioning, Refrigeration and Ventilation | Level 4 | NQF Level 04 | Passed the End Date - Status was "Reregistered" |
2023-06-30 | MERSETA |
PROVIDERS CURRENTLY ACCREDITED TO OFFER THIS UNIT STANDARD: |
This information shows the current accreditations (i.e. those not past their accreditation end dates), and is the most complete record available to SAQA as of today. Some Primary or Delegated Quality Assurance Functionaries have a lag in their recording systems for provider accreditation, in turn leading to a lag in notifying SAQA of all the providers that they have accredited to offer qualifications and unit standards, as well as any extensions to accreditation end dates. The relevant Primary or Delegated Quality Assurance Functionary should be notified if a record appears to be missing from here. |
NONE |
All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source. |