Assistant Professor, Civil Engineering em SITCOE, Yadrav, Ichalkaranji
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Thermal insulation of building
13 de Apr de 2020•0 gostou•622 visualizações
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In this presentation we will learn how the thermal insulation of building can be done. Different materials used for thermal insulation and methods to do it are explained.
1. THERMAL INSULATION
Mr. Mota Manoj H.
(Assistant professor, SITCOE)
Mr.Kate Ganesh
(Assistant professor, ADCET)
2. THERMAL INSULATION
The term thermal insulation is used to indicate the
construction or provisions by way of which transmission
of heat from or in the room is retarded.
3. ADVANTAGES OF THERMAL INSULATION
1. Comfort. Thermal insulation keeps the room cool in summer and hot
in winter. This results in comfortable living.
2. Fuel saving. Since heat transfer is minimised due to thermal
insulation, less fuel is required to maintain the desired temperature in
the room,
3. Prevention of condensation. Use of thermal insulating materials inside
a room results in prevention of condensation (or moisture deposition)
on interior walls and ceilings etc.
4. Use of thermal insulating materials prevents the freezing of water taps
in extreme winter, and heat loss in case of hot water system.
4. THERMAL INSULATING MATERIALS
Slab or block insulation
Blanket insulation
Loose fill insulation
Bat insulation materials
Insulating boards
Reflective sheet material
Light weight material
5. Slab or block insulation.
They are known as blocks or boards, 2.5 cm thick and 60 cm x
120 cm (or more) in area. These may be made of cork board,
mineral wool, asbestos cement etc. These are fixed to walls or
roofs.
6. Blanket insulation.
These are flexible fibrous rolls made from mineral wool,
processed wood fibres, cotton, animal hair etc., available
in thickness of 12 to 80 mm These are directly spread on
the wall or ceiling surfaces.
7. 3. Loose fill insulation.
These may consist of fibrous materials like rock wool, slag
wool, cellulose or wood fibre wool, etc. filled loosely in the
studding space.
8. 4. Bat insulating materials.
These are similar to blanket insulations except that these are small
in size but of greater thickness. These are also spread on surface
of walls and ceilings.
9. 5. Insulating boards.
These are used for interior lining of walls, and also for partition
walls.
Structural insulating board is manufactured by first making a pulp
of wood, cane or other materials and then pressing them in
form of boards by adding suitable adhesives. They are
available in different sizes and thicknesses.
10. 6. Reflective sheet materials.
Reflective sheet materials have high reflectivity and low
emissibility, thus offering high heat resistance.
Solar energy striking reflective surfaces get reflected and amount
of heat which may get transmitted is greatly reduced
Reflective insulations may consist of gypsum boards, steel sheet
reflective materials, aluminum, foils ; sheet aluminum
reflective materials etc.
11. 7. Light weight aggregate.
Heat resistance of concrete can be greatly increased by
using light weight aggregates like blast furnace slag,
burnt clay aggregates, vermiculile,etc.
12. Choice of insulating material
The choice of insulating material depends upon
(i) cost of material,
(ii) area to be covered,
(iii) standard of insulation required, and
(iv) coat of heating or cooling
13. METHODS OF THERMAL INSULATION
Heat Insulation by orientation
The orientation, of a building with respect to the sun has a
very important bearing on its thermal behavior.
For optimum orientation, there are usually conflicting
requirements Minimum transfer of solar heat is desired
during the day in summer while maximum heating of
rooms by solar heat is required during winter.
14. Heat insulation by shading
While shading of roof bring down the surface temperature it is
very difficult to achieve this effect in practice, especially when
the altitude angle of the sun is quite high during the period of
peak heat gain in the afternoon between 1100 h to 1500 h.
Raising the parapet wall can help only when the altitude angle of
the sun is low, but the cost may not be commensurate with the
effect obtained.
16. Heat insulation by proper height of ceiling
While the surface temperature of the ceiling does not vary with
height, the intensity of long wave radiation, emitted by the
ceiling decreases as it travels downwards
The effect of vertical gradient of radiation intensity is not
significant beyond 1 to 1.3 m. Hence it should be adequate to
provide ceiling at a height of about 1 to 1.3m above the
occupant.
17. THERMAL INSULATION OF ROOFS
Application of heat insulating materials.
Heat insulating materials may be applied externally or internally to
the roofs. In case of external application, heat insulating material
may be laid over the roof but below water proof course.
In case of internal application, heat insulating
material may be lined by adhesive or otherwise on the underside
of roofs from within
the rooms.
False ceiling of insulating material may be provided below the roof
with air gaps in between
18. 2. For flat roofs, external insulation may also be done by
arranging asbestos cement sheets or corrugated
galvanised iron sheets
3. Shining and reflecting materials may be fixed on the top
of the roof.
4. Roofs may be flooded with water in the form of sprays
or otherwise. Loss due to evaporation may be
compensate by makeup arrangements.
5. Roofs may be white-washed before on-set of each
summer
19. THERMAL INSULATION OF EXPOSED
WALLS
Heat insulation of exposed walls may be achieved by the following
ways :
The thickness of wall may be increased.
Cavity wall construction may be adopted, for external walls.
The wall may be constructed out of suitable heat insulating material
provided structural requirements are met.
Heat insulating materials may be fixed on the inside or outside of
the exposed wall,
Light-coloured white-wash or distemper may be applied on the
exposed side of the side.
20. THERMAL INSULATION OF EXPOSED
DOORS AND WINDOWS
This may be achieved by any one of the following means :
(i) External shading, such as louvered shutters, sun breakers
chhajjas,
(ii) Internal shading, such a curtains
(iii) Reduction of heat transmission…. Where glazed windows
and doors are provided, reduction of heat transmission may be
achieved by providing insulating glass or double glass with air
space or by any other suitable means.