comparison of different interior insulation materials 18... · 2016-01-19 · comparison of...

Comparison of different interior insulation materials

A. Bishara1, R. Plagge2

1 Technical university of Dresden, Institute of climatology, Germany, 3encult project, [email protected]

2 Technical university of Dresden, Institute of climatology, Germany, 3encult project, [email protected]

ABSTRACT

A wide range of perspectives is offered by the

opportunity to improve insulation standards of

historically listed building through internal insulation

and at the same time increase thermal comfort. On

the one hand, thermal renovation contributes in a

significant way to achieve the Kyoto-target. On the

other hand, insulation leads to an increase of thermal

comfort and therefore to an increase in the values of

historical buildings, and the attractiveness of the

living environment will increase as well. Interior

insulation offers in many cases the only appropriate

way to improve thermal insulation standards.

External insulation becomes impracticable due to

aesthetic aspects such as valuable stucco or brick

facades elements. Also, technical requirements such

as limiting distances or consisting frontage do not

allow for external insulation. for example, internal

insulation can be advantageous in temporarily

occupied rooms (meeting rooms, churches, schools,

banquet halls, etc.) where significantly faster energy-

efficient heating will be guaranteed [1].

Keywords

Thermal insulation system, internal insulation,

hygrothermal simulation, diffusion brake, historical

building, condensation, diffusion-open, capillary active.

1. Thermal insulation systems for internal

insulation

The use of interior insulation systems has been

structurally studied for over 20 years in the course of

attempted thermal renovation of our monuments. In this

context, particular attention is given to the expected

moisture accumulation in the walls’ cross section. There

are two principal possibilities to confront this moisture

problem depending on the way internal insulation is

executed:

1.1 Diffusion brake interior insulation:

The vapor diffusion flux into the wall is disabled by this

interior insulation system. Usually, vapor barrier-foils,

dense interior plaster, or approximate diffusion-proof

insulating foams are used. As a positive result should be

considered, condensation inside the structural element

should be avoided. But otherwise the negative impact is

an obstacle for dehydration processes, e.g., wind-driven

rain. Even design quality for component connections,

penetrations and deformations, (for instance beam heads

of wood beam ceilings) is required, which is very

difficult to realize [2].

1.2 Diffusion-open, capillary-active interior

insulation systems:

These systems allow vapor diffusion into the walls,

buffer the resulting moisture and remove the liquefaction

from the condensation zone back inside [3, 4]. The

moisture load of the wall is therefore considerably

reduced. The hygroscopic storage capacity of a

diffusion-open, capillary-active interior insulation system

buffers humidity peaks of indoor air and regulates the

indoor climate. The capillary action ensures that

moisture is distributed rapidly and widely inside the

insulation during the winter period. This accelerates the

drying process and improves the effect of the insulation.

Crucial for the functioning and performance of the

internal insulation is the interplay between moisture

buffering, vapor and liquid water transport. Moisture is

buffered and transported in the hygroscopic and also in

the over-hygroscopic range. Therefore, an assessment of

internal insulation requires the exact knowledge of these

variables and needs more sophisticated measurements

than usual. The following figure 1 shows the principle of

capillary-active inner insulation.

Abbildung 1. Wirkprinzip der kapillaraktiven

Inside outside

Water vapor

Diffusion-open, capillary-active interior insulation

Water content

Condensate level lies on the

cold side of the insulation

High drying potential

Good thermal insulation

Good moisture buffering

Mold resistance

Faster redistribution of the condensate by capillary

Faster evaporation

Reduction of local moisture

Figure 1: Operating principle of capillary- active inner

insulation: Due to the existing temperature difference

between inner and outer wall, water vapor diffuses

into the construction.

2nd European Workshop on Cultural Heritage Preservation 2012 (EWCHP 2012)

1

At the point where the dew point is reached, water vapor

condenses and accumulates in the pores of the insulation

material. The insulation material transports the

condensation back to the surface because of its inward

directed capillary forces and the ability to conduct water

in its pores [5, 6]. The water is discharged from the

surface into the room. In the last 20 years, numerous

insulation systems have been developed and optimized

for interior insulation use. The development objective for

diffusion retarding systems is the reduction of the

insulation value and the improvement of the durability of

foil systems. Multi-functionality is the central

development goal for diffusion-open, capillary-active

systems. This requires an extensive development effort.

The improvement of the insulation value, the humidity

regulation, the integration of fire protection functions,

the soundproofing, and also the coupling to existing

structures is crucial for the structure. This multi-

functionality leads to an optimization process, so that

different interior insulation systems can be used wisely,

depending on the requirements of each interior insulation

[7].

Abbildung 2. Beispiele für unterschiedliche Dämmstoffe, die als Innendämm

Calcium silicate Mineral foam Mineral fiber Perlite

Foam glass Wood fiber Cellulose PUR

Figure 2: Examples of various insulation materials that

are used as interior insulation.

Figure 3: Product development at the IBK R & D lab.

In collaboration with a number of manufacturers of

building materials, the phases of material development

are running through several times until a suitable product

is optimized. Subsequently, the construction

development and market integration is done through test

houses and applications [8].

tretretre

Pore volume distribution Sorption isotherm Water retention

Liquid water lead Water vapor diffusion Thermal conductivity

Figure 4: Hygrothermal material functions of product

variants. E.g. the product development of calcium

silicate board of building material manufacturer

Calsitherm (the blue curve corresponds to the

optimized product).

1.3 Optimization cycle

Phase 1: The manufacturer of building materials

establishes appropriate product variants for interior

insulation. All components of the system are considered

here (variation of material components and additives,

manufacturing processes, etc.)

Phase 2: Measurement of hygrothermal material

parameters of different product variants with modified

properties. (Use of modern technologies to detect hygric

and thermal properties, which provide realistic material

functions in conjunction with a physical material model.)

Phase 3: Use of the material functions in the numerical

simulation and analysis of selected structural details. The

comparison of product variants allows statements about

the progress of material development. (Benchmark tests)

For future direction of material development, the results

of laboratory tests and numerical simulations will be

made available again to the manufacturers of the

building materials. Positive development steps then

follow the results. This material optimization cycle is

repeated until the adjustment of the aforementioned

material parameters reaches an optimum.

1.4 Product testing phases:

Phase 4: In this phase, the optimized product is tested

experimentally. These experiments serve to verify

material components and construction and provide the

verification of the functionality of the interior insulation

system. (Construction development and construction

testing).

Phase 5: The interior insulation system is used in a test

house after the end of the development phase (market

integration). The functionality and feasibility of the

insulation system is tested on location under real

conditions. (Measurement of hygrothermal conditions

with suitable sensors at selected positions in the

construction: temperature, relative humidity, material

moisture, etc., as well as the climatic conditions, air

temperature, relative humidity, radiation, rain, etc.,

Pore Volume Distribution Sorption isotherm Water retention

Liquid water lead Water vapor diffusion Thermal conductivity


2

application training for engineers of building materials

manufacturer).

Humidity and temperature behavior of the studied test

houses are calculated in parallel with the software

DELPHIN by using the measured local climate data [9].

If the results of the simulation agree with the measured

data, then the running processes are reproduced by the

simulation software with its implemented physical

models. The material functions can then be used for

valuation of any wall constructions. A comprehensive

assessment of product safety can thus be met.

The last step is the application of the interior insulation

system for renovations, together with planning and

implementation.

2. Possibilities of hygrothermal evaluation

of wall constructions

The moisture protection must be considered a priority in

the renovation planning to ensure the permanent success

of an energetic building renovation. The following

should be considered as well: the formation of

condensation, rain, ascending humidity and introduced

building moisture and thermal bridges of some

construction. Another important aspect concerns the

compatibility of interior insulation and underground. For

an interior insulation system to become functional,

multiple layers have to be considered. The interior

insulation should be dimensioned so that the surface

condensation is avoided and the internal condensation is

limited, so that the drying potential obtained remains.

Calculation methods (e.g. COND) and simulation

programs (e.g. DELPHIN) are currently available as

planning tools for the planner. The use of these planning

tools requires knowledge of each required building

material parameters. Manufacturers are usually ready to

allow the determination of not yet existing parameters for

their new materials. For old building materials,

appropriate databases (e.g. MASEA) are available.

3. Comparison of interior insulation

systems based on practical examples

Sustainable functioning of the construction has the

highest priority of the energy-efficient renovations of the

listed buildings. The protection against moisture is the

first priority, followed by heat protection. Some

constructions are very sensitive; therefore, scientific

monitoring of energy-efficient renovation would be

appropriate.

3.1 Practical example: Wilhelminian house in

Dresden- New City

On the basis of the example of a wilhelminian house in

the Dresden-New City some measured and calculated

results are compared below (Figure 5). The typical

brickwork and sandstone veneer facade of the house is

listed. An increase of thermal protection can therefore

only be achieved by an inner insulation. In this case, a

calcium silicate board, capillary-active insulation is used

[10, 11]. The application of measurement techniques

enables the collection of important hygrothermal

performance parameters, such as the reduction of thermal

transmission losses and the control of the moisture

behavior. It also allows an assessment of energetic

renovation concepts. The measurement results are used

to validate the existing physical models in the simulation

program and verify the forecast possibility of

hygrothermal behavior.

Figure 5: Measuring arrangement in the wall section-

Wilhelminian house in Dresden- New City.

Figure 5 shows the position and arrangement of the

sensors: humidity and temperature sensors in the critical

zone, which were then installed in the condensate

potential level on the cold side of thermal insulation.

Additional humidity and temperature sensors detect the

near-wall microclimate on the outside of the wall with

interior insulation. The hygrothermal situations in the

wall cross-section are simulated numerically with the

program DELPHIN. These are considered as the locally

measured climate boundary conditions. The comparison

of the measurement data and the calculated temperatures

in the condensation zone agree sufficiently, as well as the

heat flux over the inner wall surface [12].

hh

Temperature, cold side, insulation

Heat flux, surface of the inner wall

Measured Calculated

Calculated Measured

Tem

per

atu

re °

C

Hea

t fl

ux

den

sity

in W

/m²

Figure 6: comparison of measured and calculated

(simulation software DELPHIN) time profiles of the

temperature in the condensation level (top), the heat flux

density on the inner wall surface (bottom).


3

Figure 7: Comparison between measured and calculated

time profiles of relative humidity in the condensation

level.

By comparing of measured and calculated humidity, it is

noticed that the curves stand below 90% during the

entire time. The condensation range starts at 95%

relative humidity. It is assumed that in the considered

wall cross-section no condensation problems are

occurring based on an appropriate thickness of the

insulation and on the effect of the unsteady climate. With

increasing insulation thickness, the temperature drops on

the cold side of the insulation and the risk of

condensation rises.

3.2 Example of building: Hampel Warehouse

City in Potsdam

The four-story granary building was built in 1834/35 as a

timber frame construction and faced later with red

bricks, according to the design of Karl Hampel and

collaboration of Karl Friedrich Schinkel. After 10 years,

the building was enlarged at the corner areas. Each of the

last three window axes increased like a tower with an

extra floor. The remarkable design quality of this early

industrial building defines the extreme historic value of

this construction. The general description of the building

structure shows that the granary is a timber-framed

construction. The building was subsequently veneered

with red bricks to reduce driving rain entry into the

construction. Due to high driving rain, the façade has

been provided by Schinkel with a transparent water-

repellent paint. The enlargement at the corners has been

carried out with a grouting grout [13, 14, 15].

Figure 8: Warehouse city in Potsdam.

Figure 9: photo Schinkelspeicher, left old inner wall and

timber-framed construction; range of relative humidity

at the time of maximum moisture load: Uninsulated

center, right with 80mm clay insulation, cork insulation

with driving rain load (simulation).

During the planning of the interior insulation the specific

situation of the granary is taken into account. Hence, an

open-diffusion clay insulation and cork- diatomaceous

systems that is specially adapted to timber-framed

constructions is used. A 12mm thick moisture regulating

plaster over reed rabitz is applied inside. The energetic

evaluation of the whole construction assigns the chosen

buildup the EnEV-Standard 2007 minus 28% [16].

Figure 10: Interior insulation System (insulation loam

cork) Warehouse city in Potsdam.

Figure 9 demonstrate clearly the hygric situation for both

the existing and the insulated status. Insulated wall

structures are relatively dry close to the inner wall

surface, but the humidity increases towards the outside.

Because of the insulation, less heat gets into the

construction, whereby evaporation will be limited. If the

penetrated moisture cannot dry due to driving-rain load

during the cold period of the year, the risk of frost

damage for the historic brick increases. Therefore, the

rain entry is reduced through a surface treatment

according to Schinkel. A classical driving-rain protection

is not realizable using historic coatings. For this reason, a

hydrophobic impregnation with Silane- Siloxancreme for

the wall areas and a brick grouting grout for the tower

areas is adapted. Damaged joints have to be removed and

then grouted with a suitable, color coordinated joint

material. According to Heinze et. al. (2010), the

adaptation of the hydrophobic impregnation occurs

through adjusting the concentration of the hydrophobic

agent on each brick. The optimization goal is therefore

the diffusion openness with optimal drying capacity and

sufficient protection against driving-rain too [17].

Lo

cati

on

in

(m

m)

Lo

cati

on

in

(m

m)

Location in (mm)


4

3.3 Example of building: Boelkespeicher

The Hafermagazin and the Fourageschuppen, which is

followed in the longitudinal axis, were designed by

architect Boelke and built in 1844[18, 19]. Architect

Boelke developed a gabled front in the classical style

with a regular clear, three zones building and inlaid

colored horizontal brick layers following the

Renaissance example. Both buildings are designed as an

ensemble, but they vary in volume and architectural

design. Magazine [Wharehouse] 5 (Hafermagazin) is a 4-

floor masonry building, with a ceiling and support

structure made of wood as well as a hipped roof.

Magazine [Wharehouse] 7 was built as a one-floor hall

with storage floor and gabled roof (20, 21].

Figure 11: Boelkspeicher in Potsdam.

Example brick ceiling basement

Construction

Figure 12: Detail ceiling construction basement/ground

floor outer wall of the architect Mrs. Mohr, 04.09.2008.

1 wooden Parquet, 2 floating cement screed, 3 aluminum

foil, 4 PE foam insulation, 5 Brick ceiling, 6 Calcium

silicate board, 7 masonry, 8 wood baseboard,9 perimeter

insulation, 10 sealing vertical

The proof of minimum thermal insulation, according to

DIN 4108 part 2 section 6.2 to avoid mould growth, for

this detail and as well as the simulation under real

climatic conditions are as follows [22].

Figure 13: temperature, surface temperature in [°C],

outer wall (56 cm) carried out with 6 cm calcium

silicate, boundary condition according to DIN 4108 part

2 section 6.2.

Figure 14: temperature, surface temperature in [°C],

outer wall (56 cm) carried out with 6 cm calcium

silicate, boundary condition with Potsdam climate.

The comparison of the graphs in figure 10 shows

disagreements between the standard defined climate and

the real climate conditions. The climate defined by the

standard at -10 °C over a period of 60 days does not

represent the real conditions in most cases. Via

numerical simulation, radiation (solar gains, long-wave

radiation) and precipitation (driving-rain, wind direction

and wind speed) are considered in the calculation. Figure

10 shows the real climate on a climatically unfavorable

day (January 2th). However, continuous information is

available for the whole calculation period (usually 3-5

years). This makes it possible to evaluate events in detail

at any time. It is possible to represent temperature, water

content, humidity, heat flow, moisture flow (liquid or

vapor) etc., because the calculation exports any status

variables. The humidity of the construction on April 22th

is shown in the following figure 15.

Inside

Outside

Basement

Inside

Outside

Basement

Ground floor

Basement


5

Figure 15: Relative humidity on 22th April, boundary

condition according to Potsdam climate.

The area of floor beam bearing was calculated with edge

insulation of PS foam (d = 3 cm, contrary to build-up in

the construction detail, figure 9) to buffer different

expansions of the materials because of temperature as

well as ground movements. This represents a

constructive favorable and practical variant. A separating

layer of bituminous felt under the ceiling supports, which

is also not contained in detail, should also be

[is]incorporated. The field of relative humidity in figure

11 shows that no damaging moisture occurs in the inner

sector. There is higher relative humidity in the

condensate range between inner insulation and the brick

wall. However, the humidity can dry from the inside as

well as from the outside.

w

Rewerwer

Interior insulation

Interior insulation

Tem

pe

ratu

re in

[°C

]

Time in [a]

Figure 16: Shows the surface temperature (inside) of the

external wall (56 cm thick, at corner of wall connection)

in magazine 5, calculated with interior insulation 8 cm

and 10 cm calcium silicate, outdoor climate - Potsdam-

2nd und 3nd calculation year is presented with begin

January 1th.

err

rrrew

Interior insulation

Interior insulation

Re

lati

ve h

um

idly

in [

%]

Time in [a]

Figure 17: Relative humidity (inside) of the external wall

(56 cm thick, at corner of wall connection) in magazine

5, calculated with interior insulation 8 cm and 10 cm

calcium silicate, outdoor climate - Potsdam- 2nd und

3nd calculation year is presented with begin

January 1th. .

Figure 16 and 17 show temperature and humidity in the

corner of the wall connection for two different

thicknesses. The surface moisture is reduced during the

winter months with increasing thickness of the insulation.

4. Summary and Conclusion

Energy-efficient renovation does not have to conflict

with the respectful handling of our architectural cultural

heritage. The use of new material technologies in

historical monuments should be accompanied by an

advanced evaluation of renovation methods (e.g. by

building physics laboratory tests and application of

modern simulation tools). The historic preservation as

well as the hygric-energy performance of buildings

should be considered as well. Interior insulation of

historic buildings represents a challenge in several

aspects. Are new materials compatible with the existing

building and does it make any sense to postulate

insulation at all? What is the potential for energy

budgeting? But risks of damage also have to be

quantified. How are the utilization requirements in

accordance with protecting of the building envelope?

The energetic renovation and conversion offer a chance

to preserve valuable and culturally relevant buildings.

For this reason, it is required that the planning of interior

insulation agree with the construction. The examples

show that the following topics are significant for this

planning: selection and dimensioning of an internal

insulation, moisture load of the structure and driving-

rain protection, realization of construction details and

thermal bridges, and of course special cases such as salt

load of a construction. The use of special technologies

such as measurements and laboratory tests for building

diagnostic and material valuations as well as the

numerical simulation method for coupled moisture and

heat transfer processes are essential to implement this

planning. Ascending moisture, influence of gravity,

driving-rain and humidity under real climatic conditions

can then be considered. Complex geometric details such

as window connections or ceilings integration can also

be evaluated and optimized. Condensation ranges and

thermal bridges will be shown and thus construction

Inside

Outside

Basement


6

damages are sustainably avoided. In this article, the

function principle of a capillary-active interior insulation

is explained. There are also specific material properties

and climatic boundary conditions which are required for

the assessment. The use of an interior insulation system

in a Construction in Dresden is also presented. For the

dimensioning of insulation and risk estimation, the

method of numerical simulation of coupled heat and

moisture transport processes under real climatic

conditions is used. It is shown in the present study that

capillary-active interior insulation has a great impact on

energy-saving renovation of buildings. In this context,

the knowledge of hygro-thermal functions of the building

materials is necessary. The numerical simulation method

offers a valuable contribution to dimension insulation as

well as risk assessment.

5. References

[1] DIN EN ISO 12570, 12571 Wärme- und

feuchtetechnisches Verhalten von Baustoffen und

Bauprodukten. Bestimmung des Feuchtegehaltes durch

Trocknen bei erhöhter Temperatur (ISO 12570:2000);

Deutsche Fassung EN ISO 12570: 2000.

[2] DIN EN ISO 14683, Wärmebrücken im Hochbau .

Längenbezogener Wärmedurchgangskoeffizient.

Vereinfachte Verfahren und Anhaltswerte (ISO

14683:1999); Deutsche Fassung EN ISO 14683:1999.

[3] EN 12114, Wärmetechnisches Verhalten von Gebäuden .

Luftdurchlässigkeit von Bauteilen. Laborprüfverfahren;

Deutsche Fassung EN 12114:2000.

[4] WTA Fachwerkinstandsetzung nach WTA, Band 1,

Merkblätter 8-1 bis 8-9, Adeficatio-Verlag, Freiburg 2001

[5] Grunewald, J. 1997: Diffuser und konvektiver Stoff- und

Energietransport in kapillarporösen Baustoffen. 9)

Dresdner Bauklimatische Hefte, Heft 3, Jahrgang 1997.

[6] Grunewald, J. & R. Plagge 2000: Nichtisotherme

Berechnung des Feuchtigkeittransportes mit Hilfe des

Programmes DIM 3.1. Internationale Zeitschrift für

Bauinstadsetzen und Dentkmalpflege, 6. Jahrgang, Heft 4,

2000.

[7] Grunewald J., R. Plagge & P. Häupl 2001: Numerical and

experimental investigation of Coupled Heat, Air,

Moisture and Salt Transport Problems. ASHRAE 2001

Conference, Oak Ridge, USA.

[8] Häupl, P., R. Plagge & H. Fechner 2001: Hygrische

Materialfunktionen von porösen Baustoffen.

Gesundheitsingenieur, Haustechnik - Bauphysik -

Umwelttechnik, 122. Jahrgang, 305-316.

[9] Jahn, J. 2005: Speicherstadt Potsdam, Konzept zur

kulturvollen Entwicklung einer innerstädtischen

Industriebrache. In: SELPH2 – Im Herzen des

Europäischen Parlaments Green Hydrogen Initiative,

September 2005, 43 Seiten.

[10] Kühnel Architekten 2007: Die Speicherstadt Potsdam.

www.k-k-architekten.de

[11] Plagge, R., F. Meissner & C. Conrad 2008: Messung,

Beschreibung und Optimierung der hygrothermischen

Eigenschaften des Cellco- Wärmedämmlehms. Pro Inno II

Forschungsbericht 2008, 147 Seiten.

[12] Ruisinger, U. & R. Plagge 2008: Fachwerk und

Innendämmung - Die Austrocknung zum Innenraum als

wichtiges Entscheidungskriterium. In: WTA-

Kompendium Fachwerkinstandsetzung nach WTA Band 3

Fraunhofer IRB-Verlag 2008.

[13] Plagge, R. 2009: Multifunktionale Wärmedämmstoffe -

Eine neue Technologie und ihre Anwendung. In 3.

Internationales Anwenderforum Energetische Sanierung

von Gebäuden, ISBN 978-3-934681-92-7.

[14] Plagge, R. 2011: Energetische Sanierung der

Speicherstadt Potsdam – Schinkelspeicher,

Boelkespeicher und Persiusspeicher. In 1. Internationaler

Innendämmkongress, ISBN 3-940117-07-0, 135-142.

[15] Künzel, H. M. 1998: Austrocknung von

Wandkonstruktionen mit Wärmedämm-Verbundsystemen.

In: BAUPHYSIK 20 (1998), Heft 1, Verlag Ernst & Sohn,

Berlin 1998, S. 18-23.

[16] Lutz, P., R. Jenisch, H. Klopfer, H. Freymuth, L. Krampf

& K Petzod 1994: Lehrbuch der Bauphysik - Schall,

Wärme, Feuchte, Licht, Brand, Klima - 3. neub. Auflage

Stuttgart - Teubner 1994, ISBN3-519-25014-4.

[17] Heinze, P., R. Plagge & J. Engel 2010: Adaptive

hydrophobe Imprägnierung schlagregenbelasteter

Ziegelfassaden. Ed. H. Venzmer, Europäischer

Sanierungs-kalender 2010, S. 251-259.

[18] Plagge, R., J. Grunewald & P. Häupl 2006: Öko-

effiziente Renovierung von historischen Gebäuden. WTA

Almanach 2006 Bauinstandsetzen und Bauphysik -

Restauration and Building- Physics, WTA Publications -

ISBN 3-937066-05-5, 111-130.

[19] Plagge, R. 2005: Hygrothermal Characterization of

Building Materials. In Study of moisture movement in

building material and its simulation analysis, Seminar

Book of Kyoto University, Katsura Campus, Japan, 20-41.

[20] Plagge, R. 2011: Abstimmung zwischen Feuchtezustand,

Schlagregenschutz, Abtrocknung und Dämmzonzept am

Beispiel der Elbphilharmonie Hamburg. In Bauforschung

und Baupraxis. ISBN 978-3-86780-216-1, 313-322.

[21] Scheffler, G.A. & R. Plagge 2012: Innendämmung

diffusionsoffen und kapillar-aktiv. Informationsbrochüre,

Xella Technologie- und Forschungsgesellschaft mbH.

[22] DIN 4108-2-3-4-7, Wärmeschutz und Energie-Einsparung

in Gebäuden. Teil 2: Mindestanforderungen an den

Wärmeschutz.


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