ASSESSMENT
COVER PAGE
FACULTY: ENGINEERING
DEPARTMENT MECHANICAL SEMESTER 1
QUALIFICATION (S) CODE (S)
NAME ADVANCE DIPLOMA AdvDMCHE
SUBJECT (S) NAME CODE (S)
HEAT TRANSFER HTR470S/HTR471S
NO OF PAGES DATE 26-Mar-25 TIME 17:30
(Including cover page)
ANNEXURE (S) 1 DURATION 3 hours
COLOUR IMAGES (Y/N) N
EXAMINER NAME Dr. C Magoda
INTERNAL MODERATOR P Senda
EXTERNAL MODERATOR C Tshamala
INSTRUCTIONS (to AGC, students, invigilators, etc)
REQUIREMENTS (e.g. 2 answer books, etc)
FOR STUDENT IN THE FACULTY OF ENGINEERING & THE BUILT ENVIRONMENT
- Answer All questions and in sequence.
- Indicate if the assessment is a closed or open book assessment.
- Only pens with permanent ink may be used when answering questions. Pencils may be used in instances
where diagrams and sketches are required.
- Return your Question Paper with your Answer Book.
- Graduate Attribute (GA): This Subject assesses graduate attribute 4: Investigations, experiments and
data analysis
DO NOT turn the page over before the starting
time
, Question 1 (15 Marks)
A house has a multi-layer composite wall constructed as shown in figure 1 below. The
temperature of the air inside the room is 30 0C, and the convection heat transfer coefficient
between the room air and the wall is 15 W/m2.K. The outer surface heat transfer coefficient
is 30 W/m2.K .
1.1 Determine the rate of heat transfer across the wall section per unit length of the wall.
Outside temperature is 10 0C [13]
1.2 If material F is removed, what will be the percentage increase in heat transfer across the
wall? [2]
KA=0.05 W/m.k
2m KB=0.04 W/m.k
1.5 m
Inside A C KC=0.02 W/m.k
KD=0.6 W/m.k
KE=0.4 W/m.k
q 1.5 m KF=1.2 W/m.k
D
F
B
2.5 m
1.5 m
E
Outside
150 mm 50 mm 100 mm
Fig 1. Composite wall
COVER PAGE
FACULTY: ENGINEERING
DEPARTMENT MECHANICAL SEMESTER 1
QUALIFICATION (S) CODE (S)
NAME ADVANCE DIPLOMA AdvDMCHE
SUBJECT (S) NAME CODE (S)
HEAT TRANSFER HTR470S/HTR471S
NO OF PAGES DATE 26-Mar-25 TIME 17:30
(Including cover page)
ANNEXURE (S) 1 DURATION 3 hours
COLOUR IMAGES (Y/N) N
EXAMINER NAME Dr. C Magoda
INTERNAL MODERATOR P Senda
EXTERNAL MODERATOR C Tshamala
INSTRUCTIONS (to AGC, students, invigilators, etc)
REQUIREMENTS (e.g. 2 answer books, etc)
FOR STUDENT IN THE FACULTY OF ENGINEERING & THE BUILT ENVIRONMENT
- Answer All questions and in sequence.
- Indicate if the assessment is a closed or open book assessment.
- Only pens with permanent ink may be used when answering questions. Pencils may be used in instances
where diagrams and sketches are required.
- Return your Question Paper with your Answer Book.
- Graduate Attribute (GA): This Subject assesses graduate attribute 4: Investigations, experiments and
data analysis
DO NOT turn the page over before the starting
time
, Question 1 (15 Marks)
A house has a multi-layer composite wall constructed as shown in figure 1 below. The
temperature of the air inside the room is 30 0C, and the convection heat transfer coefficient
between the room air and the wall is 15 W/m2.K. The outer surface heat transfer coefficient
is 30 W/m2.K .
1.1 Determine the rate of heat transfer across the wall section per unit length of the wall.
Outside temperature is 10 0C [13]
1.2 If material F is removed, what will be the percentage increase in heat transfer across the
wall? [2]
KA=0.05 W/m.k
2m KB=0.04 W/m.k
1.5 m
Inside A C KC=0.02 W/m.k
KD=0.6 W/m.k
KE=0.4 W/m.k
q 1.5 m KF=1.2 W/m.k
D
F
B
2.5 m
1.5 m
E
Outside
150 mm 50 mm 100 mm
Fig 1. Composite wall
