Building services

1. BASIC CIVIL ENGINEERING
Unit no. 3
Building services
1

2. BUILDING SERVICES
 Building Services are the systems installed in a building
to make occupant comfortable, functional, efficient and
safe.
 The building services might include-
ventilation, air conditioning, water supply, drainage,
plumbing, electrification etc.
 These are basic building services those are both basic
and vital for the daily running of building.
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3. 1.VENTILATION
 Ventilation may be defined as the process of supplying
fresh air from outside into a room & removing used up
air from inside the room
 Ventilation is the continuous process of admitting fresh
air and removing vitiated air.
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4. NECESSITY OF VENTILATION
 To create air movement so as to remove the vitiated air
or replace it by fresh air.
 To prevent and undue concentration of bacteria carrying
particles.
 To prevent and undue concentration of body odour,
fumes, dust & other industrial by products.
 To prevent flammable concentration of gas vapour or
dust in case of industrial building.
 To remove product of combustion & in some cases
to remove body heat & heat librated by the electrical
and mechanical equipments 4

5. TYPES OF VENTILATION
 The system of ventilation is basically divided into two
groups-
I. Natural ventilation or aeration
II. Mechanical or artificial ventilation
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6. NATURAL VENTILATION
 It is also called as aeration.
 Natural ventilation is the process of supplying fresh air
to and removing air from an indoor space without using
mechanical systems.
 In turn, this fresh air helps force the warm, dirty air
inside of the building out through the opening in the
roof.
 Natural ventilation is generally considered suitable for
houses & flats (i.e. for small buildings) and not suitable
for big offices, large factory or workshop.
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7.  Points considered while providing natural ventilation-
a) Doors and windows should be located to provide the
maximum inflow of air.
b) The height of building should be sufficient to allow air
movement.
c) Inlet opening should not be obstructed by trees,
partitions etc.
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8. MECHANICAL OR ARTIFICIAL VENTILATION
 In this system of ventilation some mechanical
arrangement is adopted to provide enough ventilation
to room.
 The outside air is supplied into building by positive
ventilation.
 If the supply of outside air is by means of mechanical
devices such as fan then it is termed as positive
ventilation. And for this purpose centrally located
supply fan of centrifugal type is used.
 The process of removal of the air & its disposal
outside by means of device is termed as exhaust of
air. and for this purpose wall or roof located exhaust
fans of propeller type are used.
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9.  Centrifugal type fan
 propeller type fan
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10. METHODS OF MECHANICAL VENTILATION
A. Extract or exhaust system
B. Supply or Plenum system
C. Combination of exhaust and supply system
D. Air conditioning
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11. A. EXTRACT OR EXHAUST SYSTEM
 In this system partial vaccum is created inside the
room of exhausting or removing the vitiated inside
air by means of propeller type fans.
 The extraction of air from inside permits the fresh
air to flow from outside to inside& thus it is possible
to provide fresh air to room by doors and windows.
 This system is more useful in removing smoke,
dust, and odour etc. from kitchen, latrines, industrial
plants etc.
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12. B. SUPPLY OR PLENUM SYSTEM
 In this system the space is filled with air by means
of fan but no special provision is made to remove it.
 In plenum ventilation the air inlet is selected inside
of building where the air is purest.
 In this opening the screen or filters may be fixed &
a fine stream of water may be impugned in the path
of incoming air.
 The disinfection of incoming air is achieved by
adding ozone @ the point of inlet.
 These ventilation systems are costly and are used
for factories , big offices , theatres etc.
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13. C. COMBINATION OF EXHAUST AND SUPPLY
SYSTEM
 This is also called as balance system
 As the name indicates it is the combination of
supply system and exhaust system.
 It uses input fans and exhaust fans to supply and
extract the air inside the room.
 This system gives better result as it enables full
control over air movement.
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14. D. AIR CONDITIONING
 This is most effective system of artificial ventilation
in which provision is kept for humidifying , heating,
cooling & filtration etc. Of the air to meet the
possible requirements.
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15. FUNCTIONAL REQUIREMENTS OF VENTILATION
SYSTEM
1. Rate of supply of fresh air-
 the quantity of fresh air to be supplied is depends
on the use of building
 supply rate is decided by considering several
factors like no. Of occupants, period of working, age
of occupants etc.
2. Temperature of air-
 The incoming air of ventilation should be according
to need of climate (i.e. Incoming air should be cool
during summer and hot during winter.)
 Inside and outside temp. difference should not be
greater than 8 degree cel.
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16. 3. Humidity-
 The relative humidity within the range of 30 to 70%
@ a working temp ( 21)is considered as desirable .
 When working is required to be done at high temp.
low humidity & greater air movements are
necessary for removing greater portion of heat
from the body.
4. Purity of air-
 it is essential that the ventilated air should be free
from the impurities such as odour, organic matter,
dust & unhealthy fumes of gases like CO, CO2
 Impurities depends on habits of occupants ,
volume of room, surrounding conditions etc.
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17. 5. Air movement-
 At the building where peoples are working the air
has to be changed or moved to cause proper
ventilation.
 The rate of change will depends on the volume of
structure, type of activity in premises, no. Of
persons in premises , velocity of fresh incoming air,
the quantity of heat , moisture and odour in a room
.
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18. 2.AIR CONDITIONING
 It may be defined as the process of treating air so
as to control simultaneously its temp. Humidity,
purity& distribution to meet the requirements of
conditioned space.
 The requirements of conditioned space may include
comfort and health of human beings, need of
certain industrial processes, efficient working of
commercial premises.
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19. PURPOSE OF AIR CONDITIONING
 It helps in preserving and maintaining health,
comfort and convenience of occupants of
residential building.
 In commercial premises such as theatres , bank,
shops it is done to improve working condition &
maintain comfort.
 It helps in improving the quality of products in
certain industrial processes such as artificial silk,
cotton cloth etc
 In other cases of industries it provides comfortable
working conditions for workers resulting in increase
in production. 19

20. CLASSIFICATION OF AIR CONDITIONING
1. Classification based on season-
 Summer air conditioning
 Winter air conditioning
 Composite air conditioning
2. Functional classification-
 Comfort air conditioning
 Industrial air conditioning
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21. CLASSIFICATION BASED ON SEASON
1. Summer air conditioning-
• In summar outside temperature is more than inside temp.
Hence cycle of operations involved air cooling,
dehumidifying,air distribution and air cleaning.
• 2. Winter air conditioning-
• In winter outside temp is less than inside temp.and hence
cycle of operations involves air heating, humidification, air
distribution and air cleaning.
• 3. Composite air conditioning-
• In this air conditioning required to be done for the whole
year irrespective of the outside temp. Variations hence the
cycle of operation involves humidifying together with air
distribution and air cleaning. 21

22. Cycles of operations in air conditioning-
22

23. FUNCTIONAL CLASSIFICATION
 1. Comfort air conditioning-
 This system aims at giving maximum human
comfort to the occupants of the conditioned space.
 2. Industrial air conditioning-
 In this system such a atmosphere conditions are
created ,controlled and maintained that are best
suited to the needs of industry during material
processing , manufacturing, storage etc
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24. PRINCIPLES OF COMFORT AIR CONDITIONING
1.Temperature control-
 comfortable zone- temp. Range which is suitable
for most of the peoples.
 The comfortable zones are different for summer
and for winter due to different clothing worn in two
seasons and due to changes in body.
 The effective temp zones for summer and winter
ranges between 20°C-23°C & 18°C-22°C.
 A temp of 21°Cto 22.5°C is required for comfortable
conditions regardless of outside temp.
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25. 2. Air velocity control-
 high velocity of conditioned air may causes greater
temp. Difference between outside & inside
 A velocity of 6 to 9 m/sec is considered as desirable.
3. Humidity control-
 In case of winter air conditioning is humidification( i.e.
Addition of moisture to heated air)
 In case of an summer air conditioning is dehumidification
(i.e. extraction of moisture from cooled air)
 During summer season 40-50%and for winter season
50-60% is most comfortable.
 Avg value of relative humidity between 40-60% is
desirable.
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26. 3.PLUMBING SYSTEM-
 Plumbing is the general term indicating the practice,
materials and fixtures used in the installation or
maintenance of all piping , appliances& other
appurtenances used in connection of water supply
system as well as sanitary and storm water
drainage.
 The services like water supply , drainage, sanitation
are sometimes known as plumbing services.
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27. WATER SUPPLY SYSTEM
 Water supply system is the system for collection,
transmission, treatment, storage& distribution of
water from source to consumers.
 A simple water distribution network.-
27

28.  General guidelines for laying out the pipelines-
(to prevent contamination of water supply line)
 There is no cross connection any where between
a pipe carrying potable water and the ppe carrying
used waste water.
 Water supply line and waste water pipe line
should not be located close to each other.
 There should be no back flow from any appliance
towards the source of supply.
 The pipe should be properly checked for any
damage.
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29. SERVICE CONNECTION
 A services connection is primarily a connection from
the distribution system to consumer.
 Components of domestic service connection-
29

30. I. Brass or bronze ferrule-
 Ferrule is the right angled sleeve made of brass
or bronze and it is used to control pressure in
water supply line.
II. Goose neck-
 this consist of a 40-50cm long curved piece of
flexible pipe made up of brass, copper, or lead.
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31.  The goose neck prevents the breaking of the
main service pipe due to movement that takes
place between the water main and service pipe
thus providing flexibility of the junction.
III. Stop cock or curb valve-
 It is installed in suitable chamber with cover to
close down the supply, for repaire of the plumbing
system.
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32. IV. Main service pipe-
 it may be made up of lead , G.I. Pipe, copper etc.
Its diameter may varies from12mm to 40mm.
V. Water meter-
 it measures the quantity of water used by
consumers.
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33. STORAGE TANKS-
 Water supply for the building is either continuous or
intermittent.
 Even in case of continuous supply in the mains, the
pressure of water may not be sufficient to rise to all
the floors of the building.
 In either case storage tanks are required.
 The storage tanks may be situated either at ground
level or at roof level or at both levels.
 If the pressure of water is sufficient to rise to the
roof level storage tank is provided only at roof level,
so as to store water because of intermittent
supplies.
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34.  If the pressure of water is not sufficient, the water is
first store at the ground tank from where it is
pumped to the top storage tank.
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35. DESIGN OF WATER DISTRIBUTION SYSTEM
 The water supply line for low rise building deals
with following points-
 Estimation of water requirement
 Determination of size of pipes to be used
 Principles of pipe layout.
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36. ESTIMATION OF WATER REQUIREMENTS-
 For designing the water supply system for
residential water demand of 135 lit per head per
day is considered.
 A supply of 540 lit per day is enough for family of
four.
 The water demand in case of building such as large
hospitals with bed, is about 340 lit/bed/day and for
school it is up to 45 lit/head/day.
 In many cities and towns of India, the supply of
treated water from mains is less, and it has to be
supplemented with other source such as bore well
etc 36

37. Sr. No. use Liters %
1 Drinking purpose 5 3.7
2 cooking 10 7.4
3 bathwash 35 26.0
4 Washing clothes 15 11
5 Toilet flushing 55 40.8
6 House cleaning 15 11.1
Total 135 100
Approximate pattern of domestic consumption of water
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38. SIZE OF DISTRIBUTION SYSTEM
 For average middle class house where there will
only 5 to 10 taps the pipe of minimum nominal size
20mm are adequate.
 When WC flushes are directly operated from the
overhead tank, a 25 mm size of pipe is
recommended to get sufficient flow.
 A thumb rule for sizes of pipe which supply 2 or
more branch pipe is as follows-
• 12 mm pipe can supply to 3 branches of 10 mm
size.
• 20 mm pipe can supply to 3 branches of 12 mm
size.
• 25 mm pipe can supply to 3 branches of 20mm
size
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39. The minimum permissible sizes of pipes are given in
table below-
Details of pipe Size of pipe
(mm)
Size of pipe
in (inches)
Service pipe 20 3/4
Bath tub and shower
stand
12 1/2
lavatory 10 3/8
Water closets 10 3/8
WC valve type 25 1
Kitchen sink type 12 1/2
Drinking foundation 10 3/8
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40. PRINCIPLE OF PIPE LAYOUT
 There should be no cross connection and back
flow.
 Water supply pipe and drainage pipe should not be
laid very close to each other underground or above
ground.
 All pipe work should planned so that it is accessible
for inspection, replacement and repair.
 All pipes including PVC pipes laid inside the
building as concealed pipes should always be
tested under pressure for leakage before final
concealment.
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41. HOUSE DRAINAGE -
 The arrangement is provided in a house or building,
for collecting and conveying waste water through
drain pipes , by gravity, to join either a public sewer
or a domestic septic tank is termed as house/
building drainage.
 Aims of house drain-
 To maintain healthy conditions in building.
 To dispose off the waste water from building as
early and quickly as possible.
 To avoid the entry of foul gases from the sewer or
septic tank.
 To facilitate quick removal of foul matter.
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42. PRINCIPLES OF HOUSE DRAINAGE-
 The drainage pipe should not laid by the sides of
building rather than below the building.
 The lavatory blocks should be so located that the length
of drainage line is minimum. In case of multi storeyed
building they should be located one above the other. At
least one wall of the lavatory block should be outside
wall for fixing the vent and soil pipe.
 The slope of drains should be sufficient to develop self
cleaning velocity.
 The size of drain should be sufficient ,so that flooding of
drain doesn't takes place while handling maximum
discharge.
 All the connections should be water tight.
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43.  The drainage system should have sufficient no. of
traps at suitable location.
 The entire drainage system should be properly
ventilated from starting point to final point of
disposal. It should permit free circulation of air.
 Rain water pipes should drain out rain water
directly into street gutter.
 All the materials and fittings should be hard, strong
and resistive to corrosive actions.
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44. PIPES AND TRAPS USED IN HOUSE DRAINAGE
 Pipes-
i. Soil pipe- a pipe through which human excreta
flows.(minimum diameter -100mm)
ii. Waste pipe- this pipe carries only liquid waste and not
human excreta.(for horizontal- 30-50mm and for vertical-
75mm)
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45. iii. Vent pipe- it is the pipe provided for the purpose
of ventilation of the system. a vent pipe is open at
top and bottom to facilitate exit of foul gases. the
vent pipe is provided at least 1 meter above the
roof level.
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46. iv. Rain water pipe- it carries only rain water.
v. Anti siphonage pipe - pipe installed in a house drain
to preserve the water seal of trap. this pipe means
any pipe provided in conjunction with a trap in the sanitary
fitting to prevent unsealing of the trap by back pressure.
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47. TRAPS
 Traps are the bent fittings which, when provided in
a drainage system , it always remain full of water ,
thus maintaining the water seal.
 Traps are designed to prevent sewer odors from
entering the home through the plumbing fixtures
and allows the waste water to flow through it.
 The depth of water seal varies from 25mm to 75
mm.
 Greater the depth of water seal , more effective is
the trap.
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48. CHARACTERISTICS OF TRAPS
 It should posses adequate water seal at all the time
to fulfill the purpose of its installation.
 It should be made up of non absorbent material.
 It should be simple in construction , cheap, radially
available.
 It should be self cleansing.
 It should be provided with suitable access for
cleaning.
 Its internal and external surfaces should have
smooth finish so that dirt etc. does not stick to it.
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49. TYPES OF TRAP-
 Classification according to shape-
I. P- trap
II. S- trap
III. Q – trap
 Classification according to use-
I. Floor / nahni trap
II. Gully trap
III. Intercepting trap
49

50. CLASSIFICATION BASED ON SHAPE
I. P - trap-
 This trap is used with an Indian water closet. The
traps are made from UPVC or cast-iron sheets.
This trap also has a water seal and prevents entry
of foul gases to the house.
50

51. S TRAP
 This resembles the letter S in which both the legs
are parallel to each other , discharging in a same
directions.
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52. Q TRAP
 This resembles the letter Q in which the two leg
meet at an angle other than right angle.
 This trap is used in toilet under water closet. It is
almost similar to S trap and is used in upper storey
other than ground floor.
52

53. CLASSIFICATION BASED ON SHAPE
1. Floor or nahni trap-
 This trap is provided in the floor to collect waste
water from washbasin, shower, sink and bathroom
etc.
 floor trap or Nahni trap is provided into the floor
53

54.  2. Gully trap-
 A gully trap is provided outside the building before
connecting to external sewerage line.
 It also collects waste water from the kitchen sink,
wash basins, baths and wash area
 It has deep water seal of minimum 50 mm depth
and it also prevents entry of bugs and insects from
sewer line to waste water pipes.
54

55. INTERCEPTING TRAPS
 This is special type of trap provided at junction of
house drain with the public sewer or septic tank.
 It has a deep water seal of 100 mm so as to
effectively prevent the entry of sewer gases from
public sewer line to house drain.
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56. SYSTEMS OF PLUMBING
 There are four principal systems of plumbing for
drainage of buildings-
1. Single stack system
2. One pipe system
3. Partially ventilated single stack system
4. Two pipe system
56

57. 1. SINGLE STACK SYSTEM
 This is the simplest system, in which the waste
matter from baths, sinks etc as well as foul matter
from W.C. are discharged in one single pipe called
the soil and waste pipe(S.W.P.).
 This pipe terminates as vent pipe at its top, and no
separate vent pipe is provided.
 The single stack system is effective only if the traps
are filled with water seal depth not less than 75
mm.
 The system is simple and economical since only
one pipe is used.
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58. 58

59. 2. ONE PIPE SYSTEM
 In this system a separate vent pipe is provided, and
the traps of all water closets , basins etc are
completely ventilated.
 In a multi-storeyed building the lavatory blocks of
different floors are situated one above the other, so
that the waste water discharged from various units
at different floors can be carried through common
soil and waste pipe (S.W.P.).
 The system is costlier than single stack system.
59

60. 60

61. 3. PARTIALLY VENTILATED SINGLE STACK
SYSTEM
 This modified form of the single stack system and
one pipe system.
 In this system the waste from W.C. , basins, sinks
etc. is discharged into one common soil and waste
pipe(S.W.P.) however , in addition, a relief vent pipe
is also provided which provides ventilation to the
traps of water closets.
 The traps of basins etc. are not directly connected
to the vent pipe.
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62. 62

63. 4. TWO PIPE SYSTEM
 In this system, separate soil pipe and waste pipe
(W.P) are provided.
 The discharge from W.C. is connected to the soil
pipe while discharge from bath, sinks, lavatory
basins are connected to waste pipe (W.P.).
 All traps are completely ventilated by providing
separate ventilation pipe, thus four pipes are
required.
 The discharge from waste pipe is disconnected
from the drain by means of a gully trap. The soil
pipe is directly connected to manhole.g
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