SAQA 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: 

Calculate the cooling requirements for air-conditioning applications 
SAQA US ID UNIT STANDARD TITLE
9461  Calculate the cooling requirements for air-conditioning applications 
ORIGINATOR
SGB Air-conditioning Refrigeration and Ventilation 
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY
-  
FIELD SUBFIELD
Field 06 - Manufacturing, Engineering and Technology Engineering and Related Design 
ABET BAND UNIT STANDARD TYPE PRE-2009 NQF LEVEL NQF LEVEL CREDITS
Undefined  Regular  Level 5  Level TBA: Pre-2009 was L5  8 
REGISTRATION STATUS REGISTRATION START DATE REGISTRATION END DATE SAQA DECISION NUMBER
Passed the End Date -
Status was "Registered" 		 2001-06-13  2004-06-13  SAQA 0836/01 
LAST DATE FOR ENROLMENT LAST DATE FOR ACHIEVEMENT
2005-06-13   2008-06-13  

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 does not replace any other unit standard and is not replaced by any other unit standard. 

PURPOSE OF THE UNIT STANDARD 
Determine the cooling capacity for an air-conditioned space for locations in South Africa.
Determine the conditions and volume of air to be supplied to ensure design conditions. 

LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
  • Determine the properties of air from a psychrometric chart and carry out basic calculations involving heat and mass transfer.
  • Plot airconditioning processes on a psychrometric chart and determine plant-operating parameters. 
    		•

    UNIT STANDARD RANGE 
    Single and multi zone applications. 

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    Conduct a building survey. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. Orientation of building is determined correctly. 

    ASSESSMENT CRITERION 2 
    2. The areas, orientation and shading of all heat transfer surfaces are determined and calculated correctly. 

    ASSESSMENT CRITERION 3 
    3. The inside and outside design conditions are determined correctly and corrected for time of day and time of year. 
    ASSESSMENT CRITERION RANGE 
    Including but not limited to the following: use of space, ambient summer and winter temperatures, inside temperature and relative humidity, number of people, volume of outside air, construction materials, surrounding conditions, internal loads and location of obstructions, beams etc.
     

    ASSESSMENT CRITERION 4 
    4. The consequences of selecting too high or too low internal and external conditions are stated and explained. 

    ASSESSMENT CRITERION 5 
    5. The consequences of wrong orientation or calculations are explained. 

    ASSESSMENT CRITERION 6 
    6. Correct SI units are used. 

    ASSESSMENT CRITERION 7 
    7. All details are confirmed with client. 

    ASSESSMENT CRITERION 8 
    8. The need for "zoning" is examined and explained. 

    SPECIFIC OUTCOME 2 
    Calculate external loads. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. Temperature differences across all heat transfer surfaces are determined and corrected for site conditions and expected time at which peak load will occur. 

    ASSESSMENT CRITERION 2 
    2. Solar heat gain factors are determined and corrected for site conditions and expected time at which peak load will occur. 

    ASSESSMENT CRITERION 3 
    3. Shading factors are determined and applied correctly. 

    ASSESSMENT CRITERION 4 
    4. The overall heat transfer coefficients ("U") for all heat transfer surfaces are determined or calculated correctly. 

    ASSESSMENT CRITERION 5 
    5. The outdoor air load is calculated correctly. 

    ASSESSMENT CRITERION 6 
    6. The consequences of selecting too high or too low conditions are stated and explained. 

    ASSESSMENT CRITERION 7 
    7. The correct SI units are used. 

    ASSESSMENT CRITERION 8 
    8. Design conditions are confirmed with client. 

    SPECIFIC OUTCOME 3 
    Calculate internal loads. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. Temperature differences across all heat transfer surfaces are determined and corrected for site conditions. 

    ASSESSMENT CRITERION 2 
    2. All internal loads are determined and calculated correctly. 
    ASSESSMENT CRITERION RANGE 
    Including but not limited to the following: people, lights, appliances, equipment, electric motors and miscellaneous sources.
     

    ASSESSMENT CRITERION 3 
    3. System heat gains are calculated correctly 

    ASSESSMENT CRITERION 4 
    4. The correct safety factors are applied. 

    SPECIFIC OUTCOME 4 
    Complete the heat load estimate form. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. All information required is entered and calculated correctly. 

    ASSESSMENT CRITERION 2 
    2. All additions are done correctly. 

    ASSESSMENT CRITERION 3 
    3. The effective room sensible heat, the effective loom latent heat and the grand total heat as calculated are correct. 

    ASSESSMENT CRITERION 4 
    4. The coil bypass factor selected is correct. 

    ASSESSMENT CRITERION 5 
    5. The air-conditioning process is correctly plotted on the psychrometric chart. 

    ASSESSMENT CRITERION 6 
    6. The apparatus dew point determined and selected is correct. 

    ASSESSMENT CRITERION 7 
    7. The supply air volume required is calculated correctly. 

    ASSESSMENT CRITERION 8 
    8. The plant operating parameters are specified correctly. 
    ASSESSMENT CRITERION RANGE 
    Plant capacity, Apparatus dew point, coil entering and leaving conditions.
     

    ASSESSMENT CRITERION 9 
    9. The coil capacity as calculated is checked against calculated loads. 


    UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS 
    Any person wishing to be assessed against this unit standard may apply to an assessment agency, assessor or provider institution accredited by the relevant ETQA, who may appoint a moderator to be present at the assessment.

    The assessor must have knowledge and experience of air-conditioning or refrigeration. 

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
    The importance of correctly determining the cooling and heating load for an air-conditioned space to ensure correct selection and operation of equipment.

    Theory of heat transfer. 


    Critical Cross-field Outcomes (CCFO): 

    UNIT STANDARD CCFO IDENTIFYING 
    Identify and solve problems
  • Apply drawing scales correctly 
    		•

    UNIT STANDARD CCFO ORGANISING 
    Organize and manage myself and my activities
  • Select measuring instruments 
    		•

    UNIT STANDARD CCFO COLLECTING 
    Collect, analyse, organise and critically evaluate information
  • Reading and interpreting architectural drawings 
    		•

    UNIT STANDARD CCFO COMMUNICATING 
    Communicate effectively
  • Present oral report to client 
    		•

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically
  • Determine operating parameters correctly 
    		•

    UNIT STANDARD NOTES 
    Any generally accepted heat load calculation form or method might be used.
    A generally accepted computer based heat load calculation program may be used. 

    QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Elective  20722   National Diploma: Air Conditioning, Refrigeration and Ventilation  Level 5  Level TBA: Pre-2009 was L5  Passed the End Date -
    Status was "Registered"     		 2004-06-13  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.