Change search
ReferencesLink to record
Permanent link

Direct link
Stone-wool insulation under offence of massive condensation and ice formationand their impact on moisture properties
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.ORCID iD: 0000-0003-0615-4505
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Building constructions are often under the offense of condensation. In extreme cases, watercondensation can also be accompanied by formation of frost in layers adjacent to outdoorsurfaces. In general, these problems happen due to sudden climate changes during buildingworks, misuse of building materials or delayed work on sites. Troubles with moisture proceedin the layer of thermal insulation thanks to its high moisture capacity and material thickness.Mineral wool is one of the most used thermal insulation materials in the building industry.Previous research and measurements have proved that fibrous insulations (e.g. stone wool)have varying material properties, when wet. Both thermal and moisture properties arechanged.

This paper refers to laboratory tests concentrating on existence of frost formation in stonewoolspecimens exposed to extreme moisture load and temperature gradients (Vrána, Björk,2008). The executed research of that study did show that moisture resistance factor (μ-valueor μ-factor) is affected by condensation and freezing in the material. This paper illustrates acalculation model based on the monitored indoor and outdoor data (surface T and RH) of thetested materials. These climate data were used to create a functional mathematical model thatcan simulate moisture balance of stone wool. Finally, the model was compared to outputobtained from laboratory measurements.

Keyword [en]
Stone wool, Material properties, Frost formation, Condensation, Moisture transport, μ-value, Sorption curves
National Category
Building Technologies Materials Engineering
URN: urn:nbn:se:kth:diva-11680OAI: diva2:279247
QC 20100818Available from: 2009-12-02 Created: 2009-12-02 Last updated: 2010-08-18Bibliographically approved
In thesis
1. Condensation and frost formation in fibrous thermal-insulation materials
Open this publication in new window or tab >>Condensation and frost formation in fibrous thermal-insulation materials
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Heavily insulated constructions are at present being used to strike at the vast energy consumption in residential buildings and commercial alike. They introduce a high-thickness layer of thermal insulation in the building envelopes. Such constructions have great moisture capacity and could be at risk due to moisture leakages and other moisture related problems connected to bad design, climate effects, extended construction period to late autumn and winter seasons and mishandle of building materials.

Thermal-insulation materials based on stone wool and cellulose are commonly used in a wide range of applications that harness their high thermal-insulation properties. Both these materials could be fault-prone due to their fibrous structure in case of moisture problems – e.g. built-in moisture, annually repeating condensation and frost formation in the cold climates.

The aim of this research was to observe the stone-wool and cellulose specimens in various temperature fields under extreme moisture load and to explore the issue of moisture transport and real moisture properties of the tested materials when condensation and frost formation occur. A special testing device, Thermobox, was constructed and the fibrous samples were exposed to temperature gradients simulating real conditions. The climate data as well as the moisture-transport data were registered. They were used in calculations of moisture resistance factor, µ, denoting permeability of the tested samples in the defined moist conditions. Following the laboratory measurements, a mathematical simulation was done to compare total moisture accumulation in the specimens with the practical measurements and to be able to simulate these processes in a longer time interval. Besides, a special outdoor experiment concerning the effect of outdoor climate on the stone-wool structure was executed.

Final research findings proved that the phenomenon of frost formation can exist in the fibrous insulation materials. Moisture transport properties of stone wool and cellulose were affected by the extreme water condensation and freezing, but they remained highly permeable. As regards the moisture storage in the samples, this process was continuous during the tested period and it indicated significant growth of the total water accumulation in connection with dry densities of the tested materials. This emphasises the importance of proper handling with the fibrous thermal-insulation materials and keeping them dry.

Place, publisher, year, edition, pages
Stockholm: US-AB, 2009. 43 p.
Trita-BYMA, ISSN 0349-5752 ; 2009:1
Fibrous thermal insulation, Stone wool, Cellulose, MAterial properties, Moisture transport, Condensation, Frost formation, Exterior conditions, Interior conditions
National Category
Civil Engineering Other Materials Engineering
urn:nbn:se:kth:diva-11632 (URN)978-91-7415-468-9 (ISBN)
Public defence
2009-12-11, F3, Lindstedtsvägen 26, KTH, Stockholm, 13:00 (English)
Disputationen indragen.Available from: 2009-12-02 Created: 2009-11-26 Last updated: 2012-03-22

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Vrána, TomášGudmundsson, Kjartan
By organisation
Civil and Architectural Engineering
Building TechnologiesMaterials Engineering

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 327 hits
ReferencesLink to record
Permanent link

Direct link