Isover Building Advices_1

8/2/2019 Isover Building Advices_1

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Comfort

ConcursulIsover 2007

Isover BuildingAdvices


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Sensation of Comfort

Different parameters affects a sensation ofa high comfort level inside a building

The ambient inside temperature

The temperature variations inside

The level of air-movements (draft) insideThe sensation of air freshness

The noise level in and betweenrooms/houses

The level of light inside

We want to live in a warm (or cool in thesummer), silent and safe building


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Typical Comfort issues

Sensation of cold from surfaces(walls/windows/floors)

Cold draft because of air-movements

Noise from inside the house or from our

neighboursWindows feel cold and there is often acondensation on them

In corners I see a start of mold growth

There is a bad smell in my house

The energy bill for heating is rising...


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Theoretical descriptions


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Theoretical descriptions

Thermal Comfort

Indoor air quality

Thermal performances and minimized heat flowTransmission losses

Thermal bridges

Air and wind tightness

Moisture ManagementAcoustics

Ventilation


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Thermal Comfort


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Definition of comfort

Comfort requirements have been takenaccordance with EN ISO 7730 (1995)

Thermal predicted mean vote (PMV) in accordance

with FANGERIdem for Ventilation and air renewal


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Building and climate

Summer WinterWinter S rin Autumn

Temperature

Inside temp.Good

building

Inside temp.Poor buildingInside temp.Poor building

External

temperature

External

temperature

Source: Dr Claude-Alain Roulet, Ecole Polytechnique Federale de Lausanne, Switzerland (Hope project)


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The thermal requirements for indoor climatedepends on activity and clothing

Metabolicactiv

itylevel

Hard work = 4.0 metWalking = 3.0 metSitting = 1.0 metSleeping = 0,7 met

Naked = 0 cloSummer clothing = 0.5cloCorrect indoor suit = 1 cloOutdoor clothing = 1.5clo

Examples:1. For an activity level of 1.2 and

clothing at 1.0, the optimumoperative temperature is atapproximately 22C

2. For an activity level of 2,0 andclothing at 0.5, the optimumoperative temperature is atapproximately 21C

2

1


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Thermal requirements


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Thermal comfort requirements for indoorclimate depends on ambient surface temperatures

Requirements of maximalallowable asymmetrical radianttemperatures

To understand the comfort requestsof asymmetrical radiant temperaturesgiven by ISO 7730, we can see in

figure 2 that these requirements areoutside of the accepted limits if 4% ofthe occupants are unsatisfied.

Examples: Occupants are more sensitive to variation in a warm/heated

ceiling than for a warm/heated wall/partition wall

Occupants are more sensitive to variation in a cold wall/windowthan for a cold ceiling

PMV[%]ofunsatisfie

doccupants

Asymmetrical radiant temperature [C]

warmw

allorpartit

ionwa

ll

cold

ceiling

cold

wall

orcold

win

dow

Warm

/heate

dceiling

COMFORTZONE

1

2

4

5

810

20

30

40

6080

0 5 10 15 20 25 30 35


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Climatic conditions requirements inwintertime (season of heating)

In winter, for a light workmainly in a seated positionwith clothing 1 clo (One layerof clothing) and activity 1,2(Sitting/working in an office)met (according to EN ISO7730) the conditionsaccording to the table shouldbe met:

A.B.

C.

3: 19-26C

1. T= 19-24C

2. T< 3C

A. between high and low for warm ceilings: 4C(the maximal allowable difference of surfacetemperature between the floor and theceiling)

B. between two sides of cold partitions: 10 C(the maximal allowable difference of surfacetemperature between an external wall orwindow and an internal wall)

C. between two sides of warm partitions: 20 C(the maximal allowable difference of surfacetemperature between an inside wall to otherinside vertical surfaces like a heated wall)

4.asymmetry ofmaximal radianttemperature :

between 19 et 26 C3.temperature offloor

lower to 3 C2.difference of airtemperaturebetween 0,1 and1,1 m above floor(height of theankles and thehead)

between 19 et 24 C1.understoodambienttemperature is


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Climatic conditions requirements in thesummertime

In summer, for anaccomplished light workmainly in a seated positionwith clothing 0,5 clo andactivity 1,2 met (accordingto EN ISO 7730) theconditions according tothe table should be met:

A. for cold partitions: 10 C(maximal allowable difference of surfacetemperature between a cooling wall and aninternal wall)

B. for cold ceilings: 13 C(maximal allowable difference of surfacetemperature between the floor and thecooling ceiling.)

C. for warm ceilings: 5 C(the maximal allowable difference of surfacetemperature should not be higher than 5C

between the floor and the ceiling heated bysun radiation temperature increase)

3. asymmetryof maximalradianttemperature :

lower than 3 C2.difference of airtemperaturebetween 0,1 and1,1 m above floor(height of theankles and thehead)

between 23,5 et 26,5 C1.understood

ambienttemperature is

B,CA. 1. T= 23.5-26.5C2. T< 3C


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Ventilation and air renewal requirementsin accordance with EN ISO 7730

Air flow conditions during wintertime

Average speed of air lower than 0,15 m/s

Air flow conditions during summertime

Average speed of air lower than 0,20 m/s

The figure gives the average maximum air speedpermitting to avoid that more than 20% of theoccupants complains about draft, as a functionof the ambient temperature and the degree ofturbulence.

The conditions are satisfactory when the pointrepresenting the ambient conditions is situatedbelow the corresponding curve. Its to beunderstood that the other comfort conditions,

especially the ambient temperature, arerespected.

1.

2.

Examples1. for a temperature of 21C the airspeed can be maximum

~0.13m/s to get 100% satisfied occupants

2. for a temperature of 23C and an airspeed of ~0.17 m/s, only50% of the occupants are satisfied


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ComfortIndoor Air Quality


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Ventilation and air renewal requirementsin accordance with EN ISO 7730

eCC

GV

max

min

Air renewalMinimum air exchanges of outside air

The minimum air exchanges of outside air must in principle be determined so that theconcentrations in pollutants don't pass the maximum allowable values:

WhereVmin = minimum air exchanges of outside air in m3/hG = emission of impurities in kg/h, l/h or for gas m3/h, or olf for odoursCmax = maximal allowable concentration of the considered pollutant in kg/m3,

ppm for gas, or pol for odoursCe = pollutant considered concentration of outside air in kg/m3, ppm for gas,

or pol for odours

In presence of several sources of pollutants, we take the biggest one for the calculated

air exchange for every source.An outside air exchange about 15 m3 per hour and per person (zone non-smokers) isnecessary of the point of hygienic view. This air exchange limits the concentration incarbon dioxide to 0,15% or 1500 ppm.


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Thermal performances

Minimized Heat flow


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0

50

100

150200

250

300

350

400

Completelyinsufficient

thermal

protection

Insufficientthermal

protection

Low EnergyBuildings

Isover MultiConfort House

Householdelectricity

Ventilation

Electricity

Hot Water

Heating

Comparison of Buildings

En

ergyconsumptioninkWh/ma


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Comparison of Buildings I

1.5 liters4-5 liters15-10 liters30-25 liters

Energy consumption inliters heating oil persquare meter and year

Lowest-energybuildings(essentialparameter of therequirementprofile to be metby PassiveHouses)

Low-energybuildings

InsufficientthermalprotectionThermalrenovation isclearly worth thetrouble (typical ofresidentialbuildingsconstructed in the50ies and 70ies ofthe last century)

Completelyinsufficientthermal protectionStructurallyquestionable, costof heating no longereconomical (typicalof rural structures,buildings datingfrom the early yearsof the so-calledGrnderzeit or from1945 to 1970

Building standard

The HEDGFA value (heatenergy demand related

to the gross floor area)serves as a help toassess the thermalquality of a building -NORM B 8110-5(prestandard).

kWh/ma

< 15kWh/ma

50-40kWh/ma

150-100kWh/ma

300-250

Heat energy demandGross floor area(HEDGFA) in kWh/mafor a characteristic lengthof 1mHeating degree days (HDD) =3400 Kd


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Comparison of Buildings II

0.80 W/mK

Triple glazingspecial frame

1.10 W/mK

Double glazingthermo

2.6 W/mK

Double glazing

5.10 W/mK

Single glazing

Windows

0.12 W/mK

30 cm

0.25 W/mK

20 cm

0.40 W/mK

7 cm

1.0 W/mK

2 cm

Floors to ground

0.10 W/mK

40 cm

0.15 W/mK

30 cm

0.22 W/mK

22 cm

0.90 W/mK

4 cm

Roof

0.10 W/mK

34 cm

0.20 W/mK

16 cm

0.40 W/mK

6 cm

1.30 W/mK

0 cm

Exterior wall(massive wall of 25 cm)

U-value and insulation ( =40 mW/m.K) thicknessConstruction

kWh/ma

< 15

kWh/ma

50-40

kWh/ma

150-100

kWh/ma

300-250

Heat energy demand


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1.5 liters4-5 liters15-10 liters30-25 liters

Energy consumption inliters heating oil persquare meter and year

2 kg/ma

10 kg/ma

30 kg/ma

60 kg/maCO2 emission

kWh/ma< 15

kWh/ma50-40

kWh/ma150-100

kWh/ma300-250

Heat energy demandGross floor area

(HEDGFA) in kWh/ma fora characteristic length of1mHeating degree days (HDD) = 3400Kd

Comparison of Buildings III


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Schematic description of the past and futurenet energy demand of a single-family house

0

15

3045

60

75

90

105

120

135

150

Annualenergyconsumption(kWh/ma)

Heatenergydemand

Internal thermalsources

Solar gains

Transmissionlosses

Ventilation

165

180

195

0

15

3045

60

75

90

105

120

135

150

Annualenergyconsumption(kWh/ma)

Heat energydemand

Recovery ofventilation losses

Internal thermalsources

Solar gains

Transmission

Ventilation

165

180

195

Passive house


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Typical Energy losses in a single familyhouse

30% Roof

Walls25%Windows/Openings

Thermalbridges

10% Ground 10%

10%

15% Airrenewal

Summer

Winter

Principle ofinsulation


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Transmission losses

In a house the transmission lossesdepends on the nature and the insulationcapacity of each surface between theinside and the outside

Roof

Wall

FloorWindows/openings

High transmission losses are a result ofpoor insulation and means

higher energy use (=higher cost forheating and more pollution)

decreased thermal comfort anda higher risk for condensation and moldgrowth inside the building


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Thermal bridgesDefinition

A thermal bridge is the part of a building envelope where heat is

transferred at a much higher rate than the surrounding area.Two types:

Punctual thermal bridges: in W/KLinear thermal bridges : in W/mK

Where do they occur?In constructions there are always risks for thermal bridges*coming from

The structure of the buildingThe joints between the building parts (Windows, doorsetc.)

In order to minimize these thermal bridges, special attention hasto be put on

the choice of the components/materials in theconstructionthe detailing work around openingsthe design/insulation of the building structure joints

ConsequencesLess comfortLoss of heat => Higher energy costsRisk of condensation and mold growth

*) bridges leading the cold from the outside to the inside in the winteror the heat from outside to inside in the summer

The challenge is to design a building whichhas as few thermal bridges as possible inorder to optimize the comfort, keeping theheat inside the building and minimizing therisk of mold growth

OK !


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Thermal bridges, U

*) bridges leading the cold from the outside to the inside in the winteror the heat from outside to inside in the summer

The challenge is to design a

building which has as fewthermal bridges as possiblein order to keep the heat or

cold inside the building

Example:

If the window below is 1 m* 0.8 m with a -value of 0.012 W/mC in the structure

around the window U = (0.8*2+1*2)*0.012/(1*0.8) = 0.054

U= *L/A = Linear Thermal loss(W/mC)

L=Length (m)A= Area (m2)

x

y


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Ventilation and Air leaks

In a building you need a ventilation system tokeep a good indoor air climate

Renewal of airEvacuation of humidity etc.

The ventilation means that heated air goesout of the building and that cold air comes in

There are normally air leaks in the buildingenvelope causing unwanted ex- andinfiltration of air

Joints between building partsThe air-tightness in the insulations systemis not guaranteedThe windows are not air-tight etc.

The air-leaks causes worse performance ofthe insulation- and ventilation systemControlling the air leaks and the air flowmeans an improvement of the comfort butalso better energy efficiency of the building


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Air and wind tightness

Wind Wind

The envelope must be

made air-tight in order toguaranteea sensation of high comfortand avoid draft, high speed ofair and shift in temperaturedue to in- and ex-filtration ofairan optimized function of the

ventilation equipmentminimize the risk ofcondensation in theconstruction


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Air tightnessThe air-tightness is measured by a measuring the air changes per hourwith a pressure diff. of 50 Pa (Blower door test ISO 9772 EN 13829).

Blower door test

Smoke test to indicate leaks

Measuring with Anemometer(Wind speed and direction)


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Moisture management


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Safe Storage Capacity Wetting Wetting

Drying

Condensation

air convection vapor diffusion

Rain

absorption

penetration

DrainageAir convectionEvaporation-Diffusion John Straube 2001

Dynamic heat and moisture transfer

Keeping the Moisture balance

Built-inmoisture

Source: Fraunhofer Institute, Holzkirchen/Germany


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John Straube 2001

Safe Storage Capacity WettingWetting

DryingTo avoid damage evaluatehygrothermal loads duringdesign process!

Dynamic heat and moisture transfer

Make sure that the design

Source: Fraunhofer Institute, Holzkirchen/Germany


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Moisture management

There are three types of moisturetransmissions:

1.Convective air transmission loss

2.Water vapor transmission by diffusion

3.Capillary moisture transport


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Moisture management

Making sure the building moisturelevel is in balance

Good ventilation is essential:Change of air and evacuation ofthe moisture with the ventilationsystem

Short time openings of the

windows enables a moisturebalances

Warm air can hold more water vaporthan cold air:

As can be seen in the right figurecondensation (at RH* 100%)occurs at 5C. However the

absolute water vapor content islower in this volume than at atemperature of 20C => warm aircan hold more water vapor

*) RH= Relative humidity


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Critical surface temperature

The critical places for surface humidity aregeometrical and constructive thermalbridges, like corner, stored supports etc.The construction has to be designed in away that

at no surface a condensation can appearthe risk of contamination through mould

growth doesn't exist There is a high level of insulation,

thermal bridges are minimized and thewindows have a high quality

If short-term appearance of condensationat the surface should occur, theconstruction element should be designedso that damages can not occur (i.e. awindow with temporary condensation must be

able to accept the condensation until this isdried out without damage on the surface.)

In order to avoid the risk of mould growth,the relative humidity of the surfaces nearan air layer should never be higher than 80percent for a period of 60 days (or a tempof 13C or 8 days and a temp of 20C)

ei

esiRsif

>= 0,75


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Interstitial condensation

Proof that this is not the case: at the end of the summer there is no

condensation in the constructionelements

the accumulated quantity ofcondensation during the condensationperiod in the adjoining layers thefollowing values doesn't exceed:

1. 3% (absolute difference between theoriginal (17% nominal) and the maxlevel) of the mass for wood and woodenmaterials

2. 1% of volume for insulation materials3. 800 g/m2 for porous building materials

with capillary moisture transmissioneffect (i.e. concrete or bricks) 800 g/m2Porous materials withcapillary moist. Transm.

1 % of volumeInsulation

3 % of massWood

Max allowedaccumulated quantity of

the original

Material


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No drying out towards

the outside(Winter)Water proof membrane

(or i.e. Metal roof)

Air- and Vaportight barrier

Leakage in

Vapor and airbarrier

No drying out towards

the inside(Summer)

Trapped Moisture that cant get out

Diffusion Problem(Example taken from EMPA/Switzerland)


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Winte

r

Summ

er

Diffusion problems cont.

Room temperature 21 C

Summer situation

Outside-Temperature 33 C


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Acoustics


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We only can learn whatwe can hear

Speech dominates themajority of learning situations.The quality of a room'sacoustics can therefore help

determine whether teaching issuccessful or not.Furthermore the indoorenvironment of all workplacesmust help ensure that people

feel bothmentally and physicallyhealthy.


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DefinitionsSound absorption

The Reverberation time, T60is defined as

the time it takes for thesound level to decrease by

60 dB after the soundsource has been switchedoff. A sound source that emits a sound level of 100 dB is switchedoff at t=0.5 sec.

The reverberation time is the time it takes for the sound level todecrease 60 dB (the sound level is then 40 dB). The soundlevel in this example is stabilised at the background noise

level of 30 dB.

The sound propagation in rooms is differentfrom the sound propagation in free field. Soundin rooms is reflected from hard surfaces andcan negatively influence the room acoustics.


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Sound reduction

To enjoy privacy and speech audibilityin a room, the sound reduction index(DnT,w) of the partition wall should behigher than 55 dB in apartmentbuildings

Effectiveness of Sound Reduction (DnT,w)between rooms.

In several European countries thesound insulation requirementbetween rooms of differentapartments is DnT,w= 55 dB.


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Impact sound reduction ( Lw)

Sound is not onlytransferred by the air butalso by the structure

between floors and roomsBuilding structure design isgiving the result as regardsto impact noise- separatingthe floor from the structureis an important factor toreduce the nuisance fromimpact noise


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Isover BuildingDesign recommendations


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Thermal comfort- Wintergeneral recommendations

In order to maximize the thermal comfort in acold/medium cold climate:

a high level of an air-tight thermal insulation solutionis necessary to keep the cold outside and the warmair inside the building

a well designed ventilation system is required inorder to renew the air and evacuate humidity

The outgoing air should be used to heat theincoming fresh and filtered air

The size-, quality-, surface-area- and the placing ofthe window in the building is highly effecting thecomfort and special attention has to be put to this inthe design stage

The orientation of the windows should be towardsthe south and west in order to use the solar energyduring the winterA ground heat exchanger is an opportunity to pre-heat the ingoing air hence improving the comfort

pipe must resist to ground pressure, soil acidity, air- and gas-tight(water vapor, radon) and be smooth, to make cleaning easy)

In a light structure building it is preferred to use aheating floor, if a heating source is needed


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Thermal comfort- Summergeneral recommendations

In order to maximize summer comfort in a warm climate:

a high level of thermal insulation is necessary to keep the heat outside andthe cold air inside the buildinga well designed ventilation system (and/or opening of windows) is needed inorder to cool the building during the night time

the size, orientation and the placement of the window surface in the buildingis highly effecting the comfort and should be controlled

a good protection (shadings) against sun radiation through windows isnecessary and these should be installed outside the building

the energy labeling for the inside equipment for cooking, cooling/freezing,lighting, TV etc. should be at the lowest possible level and switch of thestandby on the equipment

behavior/activity of occupants is highly effecting the summer comfort

activities like cooking, lighting, watching TV etc. must be controlled

closing the outside blinds in front of the window is necessary duringday-time

a ground heat exchanger is an opportunity to cool the ingoing air andimprove the comfort

pipe must resist to ground pressure, soil acidity, air- and gas-tight(water vapor, radon) and be smooth, to make cleaning easy)

In a light structure building it is preferred to use a heating floor, if a heatingsource is needed. This floor could be used as a cooling floor in the summerand the heat should then be recuperated, i.e. for hot tap wateradditional internal heat storage mass, e.g. floors, external walls, partitionsand ceilings can be achieved by extra layers) of plaster-board (with PCM,Phase Changing Material)

The solar energy should be used to heat the tap water to the highestpossible extent


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Isover recommendation for optimalcomfort and low energy consumption

0.80W/mK

Triple glazingspecial frame

1.10W/mK

Doubleglazingthermo

2.60 W/mKDouble glazing

5.10 W/mKSingle glazing

Windows

0.12W/mK

30 cm

0.25W/mK

20 cm

0.40 W/mK

7 cm

1.0 W/mK

2 cm

Floors to ground

0.10W/mK

40 cm

0.15W/mK

30 cm

0.22 W/mK

22 cm

0.90 W/mK

4 cm

Roof

0.10W/mK

34 cm

0.20W/mK

16 cm

0.40 W/mK

6 cm

1.30 W/mK

0 cm

Exterior wall(massive wall of 25cm)

U-value and insulation ( =40 mW/m.K) thicknessConstruction

kWh/ma

< 15

kWh/ma

50-40

kWh/ma

150-100

kWh/ma

300-250

Heat energy demand

0

1530

45

60

75

90

105

120

135

150

An

nualenergyconsumption(kWh/ma)

Heat energydemand


Internal thermal

sources

Solar gains

Transmission

Ventilation

165

180

195

0

1530

45

60

75

90

105

120

135

150

An

nualenergyconsumption(kWh/ma)

Heat energydemand


Internal thermal

sources

Solar gains

Transmission

Ventilation

165

180

195

Passive house


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Recommended minimum Thermalperformances per building part

The energy consumption target for thebuilding envelope should be at leastequal or lower than 60 kWh/m2.y fornet energy consumption (Heating,ventilation and hot water supply) whichgives the recommended U-values as inthe table on the right for the differentbuilding elements

U-values in the table are put withoutspecial concerns to climate and areconsidered typical for a medium/coldclimateIt is assumed that the inertia needed inthe summer is coming from the floatingfloor or the ground floor

An additional inertia of the building

could be achieved with extra plasterboard, possibly containing PhaseChanging Material (PCM)

U < 0,06Thermal bridges

STRUCTURE


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Air tightness recommendationThe air-tightness of a building should be < 0.7 (one) air change per hourwith a pressure diff. of 50 Pa (Blower door test ISO 9772 EN 13829)

Special attention should be put on insulation and air-tight joints aroundwindows/openings to minimize the risk of leaks


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The sustainable solution toguarantee the air- and wind tightness

Fixation of anindependent air-tightness

layer/vapor retarderon the insideof the building

Making sure that there is noair-leakage around ducts etc.

Taping the overlapbetween to sheets of thevapor retarder

Guaranteeing theair-tightness betweenthe roof and the wall bygluing the connection

Making sure that there is noair-leakage between the wallstructure and theground element.

Assuring the air-tightnessand minimization of thethermal bridge betweenthe roof and windowelement

Making sure that there is noair-leakage between the walland window/doors/openings.

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Isover Building Advices_1