Assign Env Sc

8/8/2019 Assign Env Sc

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STUDENT NAME : .

PROGRAMMENAME : BTEC NATIONAL DIPLOMA IN CONSTRUCTION

UNIT 13 : ENVIRONMENTAL SCIENCE IN CONSTRUCTION

ASSIGNMENT AUTHOR : KEITH NEILL - ASSESSOR : KEITH NEILL - I .VERFIER : SURINDER VIRDI

I.VERIFIED :

YES /NO .

ISSUEDATE TUESDAY 6TH OCTOBER 2009

This assignment is complied in three parts:

PART A : Human Comfort.

PART B : Distribution of Electricity.

PART C : Fluids.

Assignment

Number

Learning

outcomes

Grading Criteria

Targeted:

Time controlled

Criteria

HAND IN DATE Resubmission

Date

PART A 1 & 2 P1, P2, P3, P4. M1,

M2.

NONE 8/12/2009 5/1/2010

PART B 3 P5, M3, D1. NONE 12/1/2009 18/1/2010

PART C 4 P7 P6, M4, D2. NONE 26/1/2010 2/2/2010

ASSIGNMENT RULES AND CONDITIONS

1 Read the Assignment brief and tasks carefully and make sure that you understand the work you should hand in

and what is required of you. If you are uncertain you must discuss with your tutor.

2. You MUST hand in the feedback sheet with the each completed work.

3. Work MUST be handed in on or before the hand in date.

4. All information sources must be referenced.

5 This assignments MUST be handed in to the relevant tutor

6 Assignments handed in after the hand in date will receive a maximum of a Pass grade.

7. Your attention is brought to the plagiarism statement within this assignment.

CENTRE FOR THE

BUILT

ENVIRONMENT

PROFESSIONAL STUDIES

AND BUILDING SERVICES


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ASSESSMENT FEEDBACK SHEET FOR PART A

Programme Title: National Diploma in Construction

Unit: Environmental Science Student Name: Date Received

Grading

Criteria /Task no

Date

Achieved/Not

achieved

Criteria and Comments

Assessors

Signature

P1 Task 1 Identify and describe four physical and four personalfactors that influence human comfort in the internal

environment.

P2 Task 2 Describe four methods used to measure factors that affecthuman comfort.

P3 - Task 3 Identify and describe the basic scientific principles thatunderpin human comfort and identify acceptable comfort

parameters.

P4 Task 4 Perform four separate calculations associated with theprovision of a comfortable internal environment and the

prevention of condensation.

M1 - Task 5 Compare the advantages and disadvantages of three

integrated thermal comfort temperatures in general use.

M2 - Task 6 Assess the effect of varying standard design options on theprovision of heating, ventilation, acoustics and lighting and

the prevention of condensation.


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Learner declaration

I declare that all the work submitted for this assignment is my own work or, in the case of group work, the work

of myself and the other members of the group in which I worked, and that no part of it has been copied from any

source.

I understand that if any part of the work submitted for this assignment is found to be plagiarised, none of the work

submitted will be allowed to count towards the assessment of the assignment.

Signed: .. Date: ..

Learning Outcomes

1). Know the factors that influence human comfort in terms of heating, ventilation,

acoustics and lighting and how these factors are quantified and measured.

2). Understand the scientific principles of heating, ventilation, acoustics and lighting

and how they are integrated to provide a comfortable internal environment and

prevent condensation.

Resources

1). Library facilities.

2). Course notes.

General Comments/Action Plan

Learners Comments:

Date: Signature:


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Unit 13: Environmental Science in Construction

Part A : Human Comfort.

Introduction.

Brief: The Central Community College in Birmingham has proposed to construct a

conference room as an extension to the main college building. Drawing No 1 shows

the sectional plan of this extension.

Although the main use of this new building will be for conferences, it may be used

for seminars and lectures.

The choice of materials, components and construction techniques will ensure that

the new construction conserves energy and creates a comfortable environment in the

conference room. The construction is as follows:

Roof pre-cast reinforced concrete slab

Ground Floor in-situ reinforced concrete

Walls - Cavity construction using bricks and lightweight concrete blocks.

The choice of doors and windows has still to be made. It gives you the opportunity to

consider a range of materials and the requirements of the building before you

finalize their selection. Other relevant information is given in the questions.

Instructions

Do not use red or green ink.

Make sure that all work is your own.

Include a bibliography to show the source of any information used.

Keep a copy of your assignment before handing it in.

Task 1

a).(i) Identify and describe FOUR physical factors which influence

human comfort.

(ii) Specify the units in which these factors are measured.

b) (i) Identify and describe FOUR personal factors which influence

human comfort.

(ii) Specify the units in which these factors are measured.

P1

Task 2

Describe FOUR instruments used to measure factors that affect human comfort and how they are

used.

(This could include thermometers, hygrometers, anemometers, sound level meters or light

meters).P2


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Task 3

Write a report (which may be supported by images, tables, charts, and / or calculations) which

includes the following :-

(a) Describe how basic scientific theory can be used to explain how human comfort can be

achieved.

(b) Acceptable values for :-

(i) Air temperature.

(ii) Mean radiant temperature.

(iii) Relative humidity.

(iv) Air speed.

(v) Rates of air change for a variety of rooms.

(vi) Sound reduction indices.

(vii) Reverberation times.(viii)Illumination levels.

(iv) Daylight factors. P3

Task 4

(a) A rectangular portacabin used during construction has dimensions

4m x 8m x 3m high.

Internal temperature; 18C

Ground temperature; 5CExternal Air Temp; 2C

(i) Calculate the U - value of the window if it is double glazed given

the following data :-

Element Thickness (m) k-value (W / mK) R (m2K / W)

Rsi 0.123

Glass 0.004 1.022Air space 0.11

Glass 0.004 1.022

Rso 0.055

(ii) Calculate the fabric heat loss for the portacabin given the following information :-

Element U-value ( W/m2K )

Floor 0.40

Window (4.0 m2

) 3.3Door (1.5 m2) 3.3

Wall 0.6

Roof 0.45


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(iii) Calculate the rate of ventilation heat loss from the portacabin if there

are two air changes per hour. (CV = 1300 J / m3 K )

(iv) Calculate the total rate of heat loss from the portacabin.

(v) What would happen to the U-value of the wall if more insulation is

provided?

(b) A cross section for an external wall of the conference room is

as follows :-

Layer Thickness

(mm)

Thermal

Resistance

(m2 0c/W)

Vapour

Resistivity

(MNs/gm)

Rsi 0.12 Negligible

Plasterboard 12 50

Aerated Concrete Block 100 70

Rockwool 100 NegligibleExposed Brick 103 80

Rso 0.06 Negligible

Inside RH 60% Internal Temperature 21oC

Outside RH 100% External Temperature 0oC

(i) Draw up suitable tables and plot the temperature profile across

the structure.

(ii) Draw up suitable tables and plot a dew point profile on the samegraph.

(iii) Discuss the risk of interstitial condensation.

(c) (i) Two vehicles, started at the same time, produce noise levels of

70 dB and 85 dB. Calculate the overall noise level.

(ii) A wall of the conference room has dimensions 15.28m x 4.5m and contains 4 windows

each of area 2.25m2. If the Sound Reduction Index for the brickwork is 60 dB and 20 dB for the

window. Calculate the overall SRI for the wall.

(iii) The conference room has a floor of dimensions 20.08m x 15.28m and a height of 4.5m.

The walls contain 14 windows each of area 2.25m2 and doors of total area 6m2. Calculate the

reverberation time at 500 Hz.

Absorption coefficients at 500 Hz are :-

Walls and door 0.02

Ceiling 0.04

Window 0.08

Plain Floor 0.06

Specify a desirable value for the reverberation time for the conference room.


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(d) Use a daylight protractor to determine the corrected sky component of daylight at location D.

(see appendix 1)

(e) A square room in the main building has sides of length 10m. It is to be fitted with lights which

have a lighting design of 2500 lumens per lamp. An average illumination of 300 lux is required,

The U.F. is 0.8 and the M.F. is 0.6. Use the Lumen Design method to calculate the number of

lamps required and draw a diagram to show how they are distributed.

(f) Describe how the following laws relating to light being emitted from a point source affect theillumination on the surface of a desk :-

(i) Inverse law.

(ii) Cosine law.

P4

Task 5

(a) State the equations used to determine :-

(i) Mean radiant temperature tr.

(ii) Inside environmental temperature tei.

(iii) Dry resultant temperature tres.

(b) Explain how the variables in each equation influence the accuracy

and usefulness of each index.

(c) Compare the advantages and disadvantages of the three integrated thermal comfort

temperatures specified in Task 5(a).

M1


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Task 6

(a) This question relates to the portacabin.

(i) Describe factors which affect solar heat gain.

(ii) Explain how solar heat gain affects the provision of heating.

(b) This question relates to the portacabin and your answer to TASK 4 (a) iii.An extractor fan is encorporated into the portacabin such that the ventilation rate is increased to 3

air changes per hour.

(i) Calculate the new rate of ventilation heat loss.

(ii) Describe the advantages and disadvantages of installing the extractor

fan.

(c) This question relates to the conference room and your answer to

TASK 4(c)iii.

(i) Calculate the new reverberation time if the number of 2.25 m2

windows in the conference room is reduced to 8.

(ii) What effect would the new reverberation time have on clarity of

speech?

(iii) What would be the effect on the reverberation time if soft furniture is

put into the room?

(d) This question relates to the square room in the main building described

in TASK 4(e).

(i) What would be the effect on the lighting design if different light

sources of 3200 lumens per lamp was used?

(ii) What would be the effect on your design if the walls of the room

was painted a darker colour?

(e) Describe different ways in which condensation can be reduced.

M2


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ppendix 1

Side elevation

D Working Plane

Plan view

D


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Toilet Toilet

To main building

Conference room

20080

15280

4290

3000

1.0m wide door x 2.0 high.

Windows 1.5 x 1.5 double glazed.


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ASSESSMENT FEEDBACK SHEET FOR PART B



Grading

Criteria /Task no

Date

Achieved/Not

achieved


Assessors

Signature

P5 Task 1 Describe the safe and effective generation, transmissionand distribution of electricity in terms of underpinning

principles.

M3 Task 2 Explain why electricity is transformed for distribution andwhy this necessitates the use of alternating current.

D1 - Task 3Justify the use of single-phase and three-phase distribution

systems in both theoretical and practical terms.



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Learner declaration



source.



Signed: .. Date: ..

Learning Outcomes

3). Understand the principles and practices used to generate, transmit and distribute

electrical power in a safe and effective manner.

Resources


2). Course notes.


Learners Comments:

Date: Signature:


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Part B : Distribution of electricity.

Introduction. This assignment investigates the way in which electricity is

produced and supplied to consumers.

Instructions

Do not use red or green ink.



Keep a copy of your assignment before handing it in.

Task 1

1a). (i) Use a labeled diagram to illustrate Flemmings right hand rule.

(ii) Describe the operation of an a.c. generator.

(iii) Sketch a graph showing a typical single phase a.c. output.

( label the axes)

(iv) Explain why the current output constantly changes

(b) Explain how electricity is transmitted from the power stations across

the country to its customers.

(c) Describe the number of phases of supply likely to be distributed to:-

(i) Domestic premises.

(ii) A factory. P5

Task 2

2a). (i) Sketch a labelled diagram of a transformer.

(ii) Describe how a transformer works.

(iii) Why is it important to have an alternating magnetic field in the core.

(iv) What is the difference between a step up and a step down

transformer ?

(b) (i) Why is electricity transformed for distribution ?

(ii) Why is distribution a.c. and not d.c. ?


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2c) A transformer has 50 primary turns and 800 secondary turns. If the input

is 12V a.c. :-

(i) Sketch a labeled diagram illustrating the main details.

(ii) Calculate the output voltage.

(d) A transformer has 200 primary turns and 25 secondary turns. If the

output is 50 V a.c. :-

(i) Sketch a labeled diagram illustrating the main details.

(ii) Calculate the input voltage. M3

Task 3

3(a). Explain why a three phase supply reduces the number of cables

required.

b(i) Draw a circuit diagram showing how a four wire supply is used

to deliver both 240V and 415V to buildings

(ii) Detail situations where 240V and 415V may be used.

(iii) Justify the supplies used for your answers to question 3b(ii)

D1


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ASSESSMENT FEEDBACK SHEET FOR PART C



Grading

Criteria /Task no

Date

Achieved/Not

achieved


Assessors

Signature

P6 Task 1 Differentiate between the properties of fluids at rest and inmotion and select appropriate formulae to solve problems

relating to fluids.

M4 Task 2 Use appropriate formulae to solve two problems in fluidmechanics and one in flow measurement.

D2 - Task 3 Compare two different flow measurement devices in termsof accuracy and ease of use.



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Learner declaration



source.



Signed: .. Date: ..

Learning Outcomes

4). Understand the properties of fluids and be able to select and use formulae to

perform calculations relating to fluids at rest and in motion.

Resources


2). Course notes.


Learners Comments:

Date: Signature:


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Part C : Fluids

Introduction. This assignment investigates the fluids at rest and fluids in motion.

Instructions Do not use red or green ink.


Show ALL working out.


Keep a copy of ALL work handed in.

Task 1

(a) Describe the properties of fluids :-

(i) at rest.

(ii) in motion.

(b) A dam wall is 40m wide and holds back a depth of 6m of water.

(i) Calculate the force exerted by the water on the dam wall.

(ii) Determine the position which the resultant force acts.

(c) A pipe of cross sectional area 0.06 m2

has water flowingthrough it at 0.4 m/s.

(i) Calculate the flow rate.

(ii) Calculate the speed of the water if the cross section tapers to an area of 0.03 m2.P6

Task 2

(a) A circular drain of 200mm diameter is laid with an incline

of 1 in 40. If the drain runs half bore and Chezys coefficient is 50 m/s

calculate :-

(i) the velocity of flow in the drain.

(ii) The discharge rate.

(b) Use Darcys formula to predict the pressure head lost in a pipe of 80mm diameter flowing

full bore with water at 0.09 m/s over a distance of 120m. Assume Darcys constant is 0.008.

(c) A venturi meter has a throat of 80mm diameter and is set in a horizontal water main of

150mm diameter. The measured pressure heads are 12.9m in the main and 9.8m in the throat.

Calculate the flow rate in the pipe given that the discharge coefficient for the meter is 0.98 and

the acceleration due to gravity is 9.81 m/s2. M4

Task 3Compare the advantages and disadvantages of two different flow measurement devices (eg the

venturi meter and weir gauge) in terms of accuracy and ease of use.

D2


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REFERRAL -Receipt

This receipt must be signed by the tutor and retained by the student as evidence.

Name of student . Date of submission

Tutors Signature. Date.

..

PART C -Receipt




.

PART B-Receipt




PART A -Receipt




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