laurentiu pestritu - fundamentals of insulation

Fundamentals of insulationFundamentals of insulationFundamentals of insulationFundamentals of insulationKuwait, February 2012

Product Manager Insulation Product Manager Insulation ‐‐MEME, India & Africa, India & Africa

DrDr Laurenţiu PestriţuLaurenţiu Pestriţu MBEMBEDrDr. . Laurenţiu PestriţuLaurenţiu Pestriţu, , MBEMBE

PROGRAM

1717::00 00 ‐‐ 1177::3030

The insulationThe insulation Why should we insulate?Why should we insulate?yy AerofoamAerofoam NBR insulationNBR insulation AerofoamAerofoam XLPE insulationXLPE insulation

February February 20122012,,KuwaitKuwait

THE INSULATION DefinitionDefinition

InsulationInsulation a material that reduces orInsulationInsulation – a material that reduces orprevents the transmission of heatheat or sound orelectricityelectricity


THE INSULATION ClassificationClassification

INSULATING MATERIALSINSULATING MATERIALS

Open cell: Closed cell:Open cell:

Rockwool

Closed cell:

polyurethanemineral wool glass wool

p y polystyrene glassg

cork (polyurethane)

g polyethylene elastomeric(p y )

(polystyrene)


WHY INSULATE? ScopeScope

Refrigeration andRefrigeration and ACACRefrigeration and Refrigeration and ACAC

TargetsTargets: :

11. . Condensation controlCondensation control

22 Minimizing thermal lossMinimizing thermal loss22. . Minimizing thermal loss Minimizing thermal loss

HeatingHeatingTargetTarget:: ‐‐minimizing thermal lossminimizing thermal loss


Selection criteriaSelection criteriaWHY INSULATE?

Temperature Temperature of the agent of the agent

Thermal conductivity Thermal conductivity (())

Vapor barrier (Vapor barrier () )

Ease of installationEase of installationEase of installationEase of installation(flexible insulation)(flexible insulation)

Fire Fire resistenceresistence‐‐ Class O Class O ‐‐


Thermal Thermal conductivityconductivityWHY INSULATE?

0,024 Air 0 034 Cross linked PE 0,034 Cross linked PE 0,035 Elastomeric insulaton 0,200 Wood0 550 W 0,550 Water 0,840 Concrete

λ‐value

0 7

0.8

0.9

0.3

0.4

0.5

0.6

0.7

0

0.1

0.2

0.3

Air Aerofoam Aerofoam Wood Water Concrete


Air Aerofoam XPE

Aerofoam NBR

Wood Water Concrete

Theory Theory ‐‐condensationcondensationWHY INSULATE?

Refrigeration and ACRefrigeration and ACRefrigeration and ACRefrigeration and AC

TargetsTargets: :

11. . Condensation controlCondensation control

22 Minimizing thermal lossMinimizing thermal loss22. . Minimizing thermal loss Minimizing thermal loss


INSULATION Theory Theory ‐‐condensationcondensation

F HVACF HVACFor HVAC scopesFor HVAC scopes

Can be used only closed‐cell insulation materials:


Important Important aspects aspects INSULATION

Top Top 5 5 important aspects regarding important aspects regarding l d ll i l til d ll i l ticlosed cell insulationclosed cell insulation

1) Strong water vapor resistance factor ‐

2) Low thermal conductivity – λλ2) Low thermal conductivity λλ

3) Use of right insulation thickness

4) Correct installation – tightness of the glued joints

) h d l d b5) Keeping the minimum distance among insulated objects


Important Important aspectsaspectsINSULATION

λλ

µµ

Heat flow (λ) and diffusion flow (µ) are caused by thedifference in the line and ambient temperatures


difference in the line and ambient temperatures

11. . valuevalueINSULATION

11. . STRONG WATER VAPOR BARRIERSTRONG WATER VAPOR BARRIER

Water vapor diffusion resistance factor Water vapor diffusion resistance factor ‐‐

70007000


11. . valuevalueINSULATIONTline + 6°C RH 0%

There is pressure difference ofThere is pressure difference ofwater vapor between ambientair and closed cell structure ofinsulation (due to temperatureinsulation (due to temperaturedifference between the line and theambient).

The pressure difference isThe pressure difference iscreating a diffusion flow whichis forcing the ambient watervapors into the insulationvapors into the insulation(towards lower temperature).

Tamb +


Tamb + 22°C RH 70%


For poor quality materials(with low value) insulationillwill get wet.

Therefore one should applyhigh quality insulationhigh quality insulationmaterials (i.e. with high valueof water vapour diffusionresistance factor )resistance factor )

Tamb +


Tamb + 22°C RH 70%


Thanks to strong value watervapor penetration is very slowand kept at limited level.p

>> 70007000

Tamb +


Tamb + 22°C RH 70%

11. . valuevalueINSULATION

THE DIFFERENCE BETWEEN HIGH AND LOW THE DIFFERENCE BETWEEN HIGH AND LOW

70007000 << 70007000

iffusion

iffusion

Vapo

rs d

Vapo

rs d


22. . λ valueλ valueINSULATION22. . LOW THERMAL CONDUCTIVITY LOW THERMAL CONDUCTIVITY

≤≤ 00,,035035

LowLow

Low quality Low quality materialsmaterials

HighHigh

10

High quality High quality materialsmaterials


10 yrs

33. . IInsulation nsulation thicknessthicknessINSULATION

33. . USING THE CORRECT INSULATION THICKNESSUSING THE CORRECT INSULATION THICKNESS

DependingDepending onon thethe pipepipe diameterdiameterthethe minimumminimum insulationinsulation thicknessthicknessshouldshould bebe calculatedcalculated (other(othershouldshould bebe calculatedcalculated (other(otherinfluencinginfluencing parametersparameters areare:: ambientambienttemperature,linetemperature,line temperature,temperature, relativerelativehumidity,humidity, surfacesurface coefficient,coefficient, thermalthermalconductivity)conductivity)

Φ 114 mm

Thickness: 19 mm Diameter: 15 mm

Thickness: 24,5 mm Diameter: 114 mm


33. . IInsulation nsulation thicknessthicknessINSULATION

The influence of pipe diameter size towards the The influence of pipe diameter size towards the heat flow heat flow (and towards the insulation thickness) (and towards the insulation thickness)

Plain surface Curved surface

A1 A1 A1

0 0 0 0

A2 A2 A2

A bigger insulation thickness is required for pipes with


bigger diameters

44. . Correct Correct installationinstallationINSULATION

Installation m st be done ith prod cts hich ass re a goodInstallation m st be done ith prod cts hich ass re a good

44. . TIGHTNESS OF INSULATION GLUINGTIGHTNESS OF INSULATION GLUINGInstallation must be done with products which assure a good Installation must be done with products which assure a good gluing at the joints and on the entire length of the pipe. gluing at the joints and on the entire length of the pipe.

TTlineline 66°°CCRHRH 00%%

Ri idRi id i l ii l i ff

RH RH 00%%

RigidRigid insulationinsulation maymay oftenoftencontaincontain spacesspaces (due(due totowrongwrong cutting)cutting) wherewhere


condensationcondensation cancan appearappear..

44. . Correct Correct installationinstallationINSULATION

Tight jointsTight joints

The system integrity (tight joints) is assured by following a right installation procedure and by using the right adhesive.

The adhesive glues the insulation surfaces through a chemical reaction which has as result the “cold vulcanization”.

“cold vulcanization” “cold vulcanization” guarantees the guarantees the


ggrequired tightnessrequired tightness

55. . Surface Surface coefficient (h)coefficient (h)INSULATION

55. . KEEPING THE MINIMUM DISTANCE KEEPING THE MINIMUM DISTANCE AMONG INSULATED OBJECTSAMONG INSULATED OBJECTS

hhrrhh = hhrr + hhcvcv

hcv = convective t ib ti f

rr cvcv

contribution of surface coefficient

hr = radiativecontribution of hhcvcvsurface coefficient



Aerofoamwith steel (flat / mat) cladding Aerofoam

h l

Aerofoampainted

with alu (silver) cladding

A fAerofoamnot painted

W W


10Wm2 . K 8 W

m2 . K 5,7 W

m2 . K


Surface coefficient h

Cladding

Without cladding / With steel

(flat / mat)With alu (silver) Static areaCladding insulation

painted

(flat / mat) cladding

(silver) cladding

Static area

Value of surface coeff. h 10 8 5,7 3[W/m2K]

,InsulationInsulation thickness

(s0)so 1,5 * so 1,9 * so 3,0 * so



Higher probability of forming condensation Higher probability of forming condensation in the static areasin the static areas

Lack of air flow (convection)Lack of air flow (convection)



Recommended distances among theRecommended distances among the insulated objectsinsulated objects

for small objects: 100 100 mmmm

for big objects: 1000 1000 mmmm

100 mm

100 mm

100 mm

100 mm

100 mm

100 mm

100 mm 100 mm100 mm100 mm

1000 mm

1000 mm1000 mm



Especially important for chilled water pipe works

Pipe works in office and hotel buildings



Effects of not keeping the right distance among the Effects of not keeping the right distance among the insulated objectsinsulated objects

Condensation


THE INSULATION ClassificationClassification

INSULATING MATERIALSINSULATING MATERIALS

Open cell: Closed cell:Open cell:

Rockwool

Closed cell:

polyurethanemineral wool glass wool

p y polystyrene glassg

cork (polyurethane)

g polyethylene elastomeric(p y )

(polystyrene)


FeaturesFeaturesINSULATIONCross linked PE at Cross linked PE at a glance…a glance…

Almost zero water vapour permeability and waterabsorption – vapour water barrier as per ASHRAE and BritishStandardsStandards

Passed a wide range of fire and smoke tests for buildingt i lmaterials

Passed toxicity levels of combustion gases as perPassed toxicity levels of combustion gases as perISO5659 IMO Resolution MSC61

Safe, fast and easy installation ‐ integrated material


FeaturesFeaturesINSULATION

No loose fibres that may cause irritations both oninstallation and service

Environmentally friendly:‐ CFC and HCFC free‐ does not contain nor use in its production substances‐ does not contain nor use in its production substancesthat contribute to Ozone Depletion Potential (ODP) andGlobal Warming Potential (GWP)


ApplicationsApplicationsINSULATIONApplication typesApplication types

Square ducts WallsRound ducts


Pipes Raised floorsStorage tanks

PropertiesPropertiesINSULATION

1. Thermal Conductivity – defines the thermal performance of

Vital Insulation Properties Vital Insulation Properties y p

the materialThe lower the value, the better the thermal performance.Varies according to mean temperature.Varies according to mean temperature.Symbol: λ, Units: W/mK, Standard: ASTM C518

2 Water Vapour Permeability – the diffusion of water vapors2. Water Vapour Permeability the diffusion of water vaporsinto the insulationThe more permissive is the material , the higher the thermal conductivitywill become over timewill become over time.Varies with temperature and relative humidity.Unit: g/h.m2, Standard: ASTM E96

3. Water Absorption – amount of water a material can absorbMore water absorbed means lower thermal performance of the material

ti


over time.Varies with density of the material.Standard: BS EN 12087

Water absorptionWater absorptionINSULATIONWater AbsorptionWater Absorption

Water absorption

Cross linked PE: Cross linked PE: 00..33%% Mineral Fiber: Mineral Fiber: 100100%%

Water absorption(% by volume)

90100

5060708090

010203040

0


Comparative Comparative performanceperformanceINSULATION

Comparison of insulation performanceComparison of insulation performance

Fibreglass NBR XLPE

N Resin bonded Extruded PVC Crossed‐linked Name glass fibers Nitrile Rubber polyethylene foam

Type of material Open cell Closed cell Closed cell

Thermal conductivity [W/mK] 0 036‐0 038 0 035 0 034Thermal conductivity [W/mK] 0.036 0.038 0.035 0.034

Water vapour permeability 75 perm‐in 0.02 perm‐in 0.00 perm‐in

Condensation control No Yes Partial

Integrated product No Partial YesIntegrated product No Partial Yes

Fibre free product No Yes Yes

Reliability in time Low High High

Ease of installationEnvironmentally friendly


Comparative Comparative costingcostingINSULATION

Condition: Indoor installation of AC ducts

Comparison of installation costsComparison of installation costsCondition: Indoor installation of AC ducts

S/NItem

Description

Estimate for 10,000m2 duct

XLPE (13mm) FIBERGLASS (25mm) ELASTOMERIC (13mm)Description work

1Insulation

Material10,000 m2 18 180,000.00 6.5 65,000.00 14 140,000.00

2 Adhesive Glue 3,000 liters NIL 0.00 10 30,000.00 10 30,000.00

3 1st coat foster 608(4 US

Gallons) NIL 0.00 60 36,480.00 0 0.00

4 canvas cloth 1,186 rolls NIL 0.00 15 17,790.00 0 0.00

5 2nd coat foster 660(4 US

Gallons) NIL 0.00 100 66,000.00 0 0.00Gallons)

6labor and

fabrication1,000 manhours 5.5 5,500.00 16 16,000.00 5.5 5,500.00

Total Cost of Labor and Materials AED 185,500.00 AED 231,270.00 AED 175,500.00


Cost savings compared to fiberglass 19.79% 24.11%

Comparative Comparative performanceperformanceINSULATION

Comparison of insulation performanceComparison of insulation performance

Condition: Installation of AC ducts in conditioned areasInsulation Thi k

Internal Surface

External Surface

Thermal C d ti it

Tline Tamb ∆T Heat

Fl Q

% Reduction

Insulation MaterialThickness

L (mm)

Surface Coefficient

fi

Surface Coefficient

fo

Conductivity

λ (W/mK)

Tline

(°C)

Tamb

(°C)

∆T

(°C)

Flow Q

(W/m2K)

Reduction of Heat

Flow

XLPE 13 22 5 7 0 034 9 30 21 34 81 79%

l f f b l

XLPE 13 22 5.7 0.034 9 30 21 34.81 79%

NBR 13 22 10 0.036 9 30 21 41.46 75%

Fiberglass 17.5 22 10 0.037 12 25 13 21.021 72%

As per BS5422:

Assuming at least 30% compression of fibreglass

ΔT1/fi + L/λ + 1/fo

As per BS5422:

fi internal surface coefficientfo external surface coefficient

Q =


Galvanized sheet metal 8 W/m2KBright reflective surface 5.7 W/m2KWhite painted surface 10 W/m2K

Questions?Questions?

laurentiu pestritu - fundamentals of insulation

Business

kuwait rh

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low value insulation

minimum insulation thickness

value tline

temperature difference

low thermal conductivity

ambient water vapors