Heat & sound insulation

Thermal & Sound
Insulation
Compiled by : FD Architects Forum
Gr. Floor , Ashoka apartment
Bhawani Singh Road
C-scheme , Jaipur -302001
Rajasthan ( INDIA)
Ph. 91-0141-2743536
Email: architect@frontdesk.co.in
Web : http://www.frontdesk.co.in/forum

http://www.frontdesk.co.in/forum/
How Heat Is Transmitted
 Conduction: the
transmission of heat
from one molecule to
another within a
material or from one
material to another
when they are held in
direct contact.
Convection: the transfer of heat by
another agent, such as air or water.
Convection Currents: the flow of air that
is created within the space.
Radiation: the
transmission of heat
through a wave motion,
similar to the way light is
transmitted.

Thermal Insulation Facts
 Fibrous materials are generally good
insulators
 Commercial insulation materials are made of:
 Glass fibers
 Glass foam
 Mineral fibers
 Organic fibers
 Foamed plastic

 Characteristics of a
good insulation
material:
 fireproof
 insect proof
 moisture proof
 resistant to any
physical change that
would reduce its
effectiveness against
heat flow
 Selection of insulation
is based on:
 Initial cost
 Effectiveness
 Durability
 Adaptation of its form
to that of the
construction and
installation methods

Heat Loss Coefficients
 British Thermal Unit: Btu, the amount of heat needed to raise the
temperature of 1 pound of water to 1 degree Fahrenheit.
 Coefficient of Thermal Conductivity: k, the amount of heat, in Btu’s,
transferred in one hour through 1 sq. ft. of a given material that is 1”
thick and has a temperature difference between its surfaces of 1
degree Fahrenheit.
 Conductance: C, the amount of heat that will flow through the material
in 1 hour / sq. ft. of surface with a 1 degree Fahrenheit of temperature
difference.
 Resistance: R, the opposite of conductivity or conductance. A good
insulation material will have a high R- value.
 Total Heat Transmission: U, represents in Btu / sq. ft. / hour with 1
degree temperature difference for a structure which may consist of
several materials or spaces.

Common insulating materials,
“R” values per inch , advantages and disadvantages
Insulating material “R”
value
Advantages Disadvantages
Polyurethane, board 6.25 Very good R-value,
can be used with
fibreglass resins
Not always easily available,
relatively expensive
Polyurethane, poured
(two-part chemical)
7.0 Very good R-value,
can be used with
fibreglass resins,
relative ease of
application
Not always easily available,
expensive, requires very careful
volume calculations
Polystyrene, sheets
(smooth)
Trade name “Styrofoam”
5.0 Readily available, low
cost, reasonable R-
value
Cannot be used with fibreglass
resins unless protected, easily
damaged
Polystyrene, foamed in
place and expanded
moulded beads. Known
as Isopor, Polypor, etc.
3.75 to
4.0
Reasonable R-values,
lower cost than
smooth surfaced
sheets
Cannot be used with fibreglass
resins unless protected, easily
damaged

Common insulating materials,
“R” values per inch , advantages and disadvantages
Insulating material “R”
value
Advantages Disadvantages
Fibreglass wool batts 3.3 Low cost, ease of
installation
Readily absorbs water or other
fluids, loses insulating value when
wet
Rock wool batts 3.7 As above As above
Wood shavings 2.2 Readily available, low
cost
Absorbs moisture and loses R-
values when wet, decays
Sawdust 2.44 Readily available, low
cost
value when wet, packs down under
vibration
Straw Readily available, low
cost
value when wet, host to insects,
etc.
Air space 1.0
approx.
No cost Has to be completely sealed to
prevent air circulation causing heat
infiltration

Spray Polyurethane Foam (SPF) Insulation
A two component mixture comes together at the tip of a gun, and
forms an expanding foam that is sprayed onto concrete slabs, into
wall cavities of an unfinished wall, against the interior side of
sheathing, or through holes drilled in sheathing or drywall into the
wall cavity of a finished wall.
sometimes also called
Foamed-In-Place
Insulation

Rigid panels/Insulation
Rigid panel insulation is made from fibrous materials (fiberglass,
rock and slag wool) or from plastic foam. They are sometimes sold
in sections designed to fit tightly in standard wall cavities.

Rigid polyurethane / Polyisocyanurate
(PUR/PIR) foam
Rigid polyurethane foam (PUR/PIR) is a closed-cell plastic. It is used as
factory made thermal insulation material in the form of insulation boards or
block foam, and in combination with various rigid facings as a
constructional material or sandwich panel. Polyurethane in-situ foams are
manufactured directly on the
building site.
Rigid polyurethane foam insulation
materials (PUR/PIR)
Polyurethane – a versatile
material

Molded Expanded Polystyrene (MEPS)
Extruded Expanded Polystyrene (XEPS)
Foam Board
Polystyrene pellets are mixed with various chemicals to liquefy them. A
blowing agent is then injected into the mixture, forming gas bubbles, which
produce a closed-cell material that are then molded into large sheets.
Commonly known as beadboard, it has an R-value of about 4 per inch of
thickness.
(XEPS) Foam Board
Extruded expanded polystyrene
insulation is similar to MEPS, but the
foaming, thick liquid is forced through a
shaping die.

Insulated Concrete Forms( ICF)
ICFs are hollow, light-weight
"stay in place" forms made of
two Expanded Polystyrene
(EPS) panels which are
connected by polypropylene
webs. During construction, the
forms are stacked to the desired
height then filled with concrete
making stable, durable and
sustainable walls.

Structural insulated panels( SIP)
Structural insulated panels (SIPs), also called stressed-skin walls, use
the same concept as in foam-core external doors, but extend the
concept to the entire house. They can be used for ceilings, floors,
walls, and roofs.
The panels usually consist of
plywood, OSB, sandwiched around a
core of expanded polystyrene,
polyurethane, polyisocyanurate,
compressed wheat straw, or epoxy.

Oriented strand board, (OSB) or Sterling board (UK), is an engineered
wood product formed by layering strands (flakes) of wood in specific
orientations.
Oriented strand board, ( OSB)

– made from fibrous materials like mineral wool, wood fiber, cotton fiber
or animal hair and manufactured to form a mat with thickness of ½” – 4
“ .
Some installed with vinyl cardboard or wire mesh and is stapled to sides
and edges of studs and joists.
Blanket Insulation

Batt Insulation
Batts are precut,
whereas blankets
are available in
continuous rolls.

Fiberglass
is a material made from extremely
fine fibers of glass. Made from molten
glass, usually with 20% to 30% recycled
industrial waste and post-consumer
content.
Rock and slag wool. Usually made from
rock (basalt, diabase) or iron ore blast
furnace slag. Some rock wool contains
recycled glass. Nonflammable.
Components of Batt and Blanket Insulation

Rock and slag wool

Loose Fill
b. Granular Insulation from
expanded minerals like
perlite, vermiculite or
ground vegetable matter.
a. Fibrous Type – from mineral wool rock, glass wool, slag wool or
vegetable fiber usually of wood fiber.
Cellulose is 100% natural and 75-85% of it is made from recycled
newsprint.

Reflective Insulation
Consists of 2 layers of 99% aluminum foil laminated to the outsides of 2
sheets of heavy-duty polyethylene air-bubble cushioning.

Corrugated Insulation
from paper formed into shapes that produced enclosed air pockets
into small regular semi – circular corrugations and covering both
sides with sheet of flat paper to give strength and produce the air
pockets.

Thermal Insulation:
Can be installed in THREE positions:
 BELOW the deck
 BETWEEN the deck and the membrane
 ABOVE the membrane

A vented air space is mandatory when using batt insulation in a flat roof!! If you use
rigid polystyrene insulation (the blue kind), no air space is necessary as it is waterproof.
Flat Roof: Insulation and
Membrane Position

Insulation BETWEEN the Deck
and the Membrane:
Traditional location for insulation:
 use low density rigid panels to support the
loads on the roof membrane without allowing
puncture of membrane
 any water vapour trapped in insulation will
cause deck to rot so use topside vents to
relieve pressure

Insulation ABOVE the Membrane:
New concept offering major advantages:
 membrane protected from extremes of heat
and cold, is on the warm side of the insulation
 membrane protected from UV radiation
 membrane protected from puncture
 insulation must be extruded polystryrene
foam board which is water resistant and
covered with a filter layer to prevent migration
of ballast

Vapour Retarders for Low Slope
Roofs:
 membrane in a protected membrane roof is
also the vapour/air barrier
 other types of low slope roofs use two layers
of asphalt saturated roofing felt bonded
together and to the roof with hot asphalt
 polyethylene film not used as it melts
 situated on the warm side of the insulation

Flat Roof: BUR (traditional) vs. Inverted (newer methodology)

is any means of reducing the
intensity of sound with
respect to a specified source
and receptor.
Sound Insulation (Soundproofing)
Soundproofing affects
sound in two different
ways:
noise reduction and noise
absorption.

METHODS of ABSORPTION
Frictional Flexural Resonating

General Classifications:
ACOUSTICAL MATERIALS
Porous Materials
Panel or Membrane Absorbers
Cavity (Helmholtz) Resonators

POROUS MATERIALS
Soft, porous materials are very good sound
absorbers. The basic acoustical characteristic
of these materials is a cellular network of
interlocking pores. Within these pores,
incident sound energy is converted into heat.
Examples of these include acoustical boards,
diffusers, soft plasters, mineral wool, and
acoustical blankets, among others.

POROUS MATERIALS
Characteristics:
Their sound absorption is more efficient at high, rather
than low frequencies. However, their acoustical efficiency
improves in the low frequency range with increased
thickness and with distance to their solid backing

POROUS MATERIALS
Categories of Commercial Materials:
Pre-fabricated Acoustical Units
Various types of perforated, fissured, or textured
materials constitute typical units in this group
Commonly used materials include:
Acoustical Boards
Acoustic Hangers
Geocoustic Tiles
Diffusers

ACOUSTICAL BOARDS
These can be installed
in several ways:
Cemented to a solid
backing
Nailed or screwed to
wood framing
Laid in a ceiling
suspension system

ACOUSTICAL BOARDS

ACOUSTICAL BOARDS
Advantages
Trade catalogs contain detailed
specifications
Easy installation and maintenance
Flexible absorption
Difficult to conceal joints between units
Soft structure subject to damage
Paint redecoration harmful to absorption
Disadvantages

ACOUSTIC HANGERS
Acoustic Hangers or baffles- a system of fiber-board panels
that are wrapped with insulation and are hung freely using
wire or rope.
Sample of Acoustic
Hangers

ACOUSTIC HANGERS

GEOCOUSTIC TILES and PANELS
Geocoustic Tiles- special prefabricated units for random
application on walls and ceilings.

GEOCOUSTIC TILES and PANELS

DIFFUSERS
Diffusers- absorptive material that have, irregular surfaces, or
angled or curved fronts, so when mounted on a wall or the
ceiling they stop parallel wall interference and prevent
standing waves.

DIFFUSERS

Acoustical Terms
 Sound: a vibration or wave motion that can be heard, reaches
the ear through air, the air vibrates back and forth in tiny
molecular motions of high and low pressure
 Decibel: the unit of measurement used to indicate the loudness
or intensity of sound; comparable to the “degree” as a
measurement of heat or cold
 Reverberation Sounds: airborne sounds which continue after
the actual source has ceased, caused by reflections from floors,
walls and ceilings
 Frequency: rate at which sound energized air molecules vibrate
 Impact Sounds: sounds that are carried through the building by
the vibrations of the structural materials themselves
 Masking Sounds: normal sounds within habitable rooms which
tend to “mask” some of the external sounds entering the room

 Decibels Reduction: expression used to indicate the sound
insulating properties of a wall or floor panel
 Sound Transmission Loss: STL, the number of decibels which
sound loses when transmitted through a wall or floor
 Sound Absorption: capacity of a material or object to reduce sound
waves by absorbing them, these sounds are otherwise reflected and
cause excessive reverberation and build up of intensity within that
area
 Noise Reduction Coefficient: NRC, the sound absorption of
acoustical materials is expressed as the average percentage
absorption at the four frequencies which are representative of most
household noises, these frequencies are 250, 500, 1000, and 2000
cycles/second
 Sound Transmission Class: STC, single number which represents
the minimum performance of a wall or floor at all frequencies, the
higher the STC number, the more efficient the wall or floor will be in
reducing sound transmission.
Acoustical Terms

The Noise Reduction Coefficient (NRC) is a scalar representation of the
amount of sound energy absorbed upon striking a particular surface.
An NRC of 0 indicates perfect reflection; an NRC of 1 indicates
perfect absorption. In particular, it is the average of four sound
absorption coefficients of the particular surface at frequencies of 250
Hz, 500 Hz, 1000 Hz, and 2000 Hz. These frequencies encompass
the fundamental frequencies and first few overtones of typical
human speech, and, therefore, the NRC provides a decent and
simple quantification of how well the particular surface will absorb
the human voice. A more broad frequency range should be
considered for applications such as music or controlling mechanical
noise.
Specifications for materials used in sound absorption commonly
include an NRC for simplicity, in addition to more detailed frequency
vs amplitude charts.
NRC : Noise Reduction
Coefficient

Sound Transmission Class (STC) is an integer rating of how well a
building partition attenuates airborne sound. In the USA, it is widely
used to rate interior partitions, ceilings/floors, doors, windows and
exterior wall configurations
The STC number is derived from sound attenuation values tested at
sixteen standard frequencies from 125 Hz to 4000 Hz. These
transmission-loss values are then plotted on a sound pressure level
graph and the resulting curve is compared to a standard reference
contour.
STC – Sound Transmission
Class

DECIBELS

Indian Standards (IS CODE) for insulation
IS CODE Title
IS 9742 : 1993 Sprayed mineral wool thermal insulation
IS 9743 : 1990 Thermal insulation finishing cements
IS 10556 : 1983 Code of Practice for Storage and Handling of Thermal
Insulation Materials
IS 12432 : Part 1
:
1988 Code of practice for application of spray applied
insulation Part 1 Mineral fibre
IS 12436 : 1988
Specification for Preformed Rigid Polyurethane (Pur)
and Polyisocyanurate (Pir) Foams for Thermal
Insulation
IS 13205 : 1991
Code of practice for the application of polyurethane
insulation by the in-situ pouring method
IS 14164 : 1994
Industrial application and finishing of thermal insulation
material at temperature above - 80° C and up to
700° C - Code of practice

Heat & sound insulation

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