13 results on '"Hansen, Tessa Kvist"'
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2. In-situ characterization of the relative humidity at the surface of building materials.
- Author
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Andersen, Helle Vibeke, Morelli, Martin, Hansen, Tessa Kvist, and Peuhkuri, Ruut
- Published
- 2023
- Full Text
- View/download PDF
3. Climate data for moisture simulations: producing a Danish moisture reference year and comparison with previously used reference year locations.
- Author
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Jensen, Nickolaj Feldt, Hansen, Tessa Kvist, Svane, Anne Marie, Morelli, Martin, and Waagepetersen, Rasmus
- Published
- 2023
- Full Text
- View/download PDF
4. Case Study:6 years of monitoring of hygrothermal conditions behind internal insulation on masonry walls
- Author
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Hansen, Tessa Kvist, Møller, Eva B., and Morelli, Martin
- Subjects
Additional insulation ,Energy demand ,SDG 13 - Climate Action ,Energy savings ,Energy retrofitting ,SDG 12 - Responsible Consumption and Production - Abstract
Energy retrofitting is performed to reduce the energy demand from existing buildings. Different measures can be implemented; however, older buildings will likely never live up to the demands of new construction. Nevertheless, the potential for energy savings must be pursued. Additional insulation is a retrofitting measure that can reduce heat loss through the building envelope and thereby provide energy savings. Internal insulation is introduced when external insulation, a more robust and moisture-safe measure, is not possible. Besides energy savings, internal insulation can provide increased thermal comfort. However, the indoor climate may suffer from internal insulation, if not designed, installed, and managed properly. Internal insulation increases the risk of moisture accumulation behind the insulation, which increases the risk of mold growth and other degradation processes. The current paper presents a case study of a building complex from 1961, where six adjoining apartments were internally insulated in 2015. The external walls were 360 mm (14.2 in.) thick, consisting of yellow brick (externally) and lightweight clinker concrete (internally). The walls were insulated with 50 mm (2.0 in.) (façades) and 80 mm (3.1 in.) (gable) insulation with a semi-diffusion tight and supposedly capillary active system, while the wall in the stairwell (north) was insulated with 50 mm (2.0 in.) of diffusion open and capillary active calcium silicate. For 6 years, the hygrothermal conditions were monitored in the interface between wall and internal insulation, where there is high risk of moisture accumulation. Measurements were performed in both northern (façade), southern (façade), and western (gable) orientations. The paper presents methods used, results from the in-situ measurements, and analysis hereof. The results show acceptable hygrothermal conditions at the interfaces and very little risk of mold growth. Furthermore, 6-12 months after applying internal insulation, the built-in moisture was dried out. Energy retrofitting is performed to reduce the energy demand from existing buildings. Different measures can be implemented; however, older buildings will likely never live up to the demands of new construction. Nevertheless, the potential for energy savings must be pursued. Additional insulation is a retrofitting measure that can reduce heat loss through the building envelope and thereby provide energy savings. Internal insulation is introduced when external insulation, a more robust and moisture-safe measure, is not possible. Besides energy savings, internal insulation can provide increased thermal comfort. However, the indoor climate may suffer from internal insulation, if not designed, installed, and managed properly. Internal insulation increases the risk of moisture accumulation behind the insulation, which increases the risk of mold growth and other degradation processes. The current paper presents a case study of a building complex from 1961, where six adjoining apartments were internally insulated in 2015. The external walls were 360 mm (14.2 in.) thick, consisting of yellow brick (externally) and lightweight clinker concrete (internally). The walls were insulated with 50 mm (2.0 in.) (façades) and 80 mm (3.1 in.) (gable) insulation with a semi-diffusion tight and supposedly capillary active system, while the wall in the stairwell (north) was insulated with 50 mm (2.0 in.) of diffusion open and capillary active calcium silicate. For 6 years, the hygrothermal conditions were monitored in the interface between wall and internal insulation, where there is high risk of moisture accumulation. Measurements were performed in both northern (façade), southern (façade), and western (gable) orientations. The paper presents methods used, results from the in-situ measurements, and analysis hereof. The results show acceptable hygrothermal conditions at the interfaces and very little risk of mold growth. Furthermore, 6-12 months after applying internal insulation, the built-in moisture was dried out.
- Published
- 2022
5. Performance of Polyethylene Vapor Barrier Systems in Temperate Climates.
- Author
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Rasmussen, Torben Valdbjørn, Hansen, Tessa Kvist, Shashoua, Yvonne, Ottosen, Lisbeth M., Pedersen, Louise Green, Nielsen, Jens Kromann, and Steenstrup, Frederik R.
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VAPOR barriers ,TEMPERATE climate ,POLYETHYLENE ,BUTYL rubber ,ADHESIVE tape - Abstract
The performance of nine different vapor barrier systems comprising polyethylene (PE) membranes were assessed. The vapor barrier systems comprised membranes of virgin PE, 100% new PE, regenerated PE and multilayered virgin and regenerated PE. Membranes were joined either with tape suited to the individual system or an adhesive base on butyl rubber. The vapor barrier systems were evaluated and compared using standard laboratory tests. Chemical analytical techniques and physicomechanical tests were used. Mechanical properties were assessed using laboratory tests recommended by the harmonized standard EN 1385. Chemical analyses followed standard laboratory protocols performed with specialized equipment and visual examination. Chemical and mechanical properties were determined before and after exposure to an aging regime comprising 168 days at 70 °C in total. The chemical stability of the plastic present in each membrane was further evaluated after an additional exposure to an aging regime comprising 50 days followed by another 30 days at 70 °C. Additional aging indicated chemical changes in the membrane material with time. However, it was not possible to distinguish between aging properties for membranes containing virgin PE, 100% new PE, regenerated PE or multilayered virgin and regenerated PE. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Written guidelines for decision making concerning the possible use of internal insulation in historic buildings
- Author
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Freimanis, Ritvars, Blumberga, Dagnija, Veidenbergs, Ivars, Hansen, Tessa Kvist, Du, Guangli, Stöcker, Eric, Sontag, Heike, Freudenberg, Peggy, Janssen, Hans, Roels, Staf, di Giuseppe, Elisa, D'Orazio, Marco, Gianangeli, Andrea, Maracchini, Gianluca, Quagliarini, Enriro, Møller, Eva B., Capener, Carl-Magnus, Lång, Lukas, Johansson, Pernilla, Lasvaux, Sebastien, Giorgi, Morgane, Favre, Didier, Padey, Pierryves, Wagner, Guy, Blumberga, Andra, and de Place Hansen, Ernst Jan
- Subjects
Insulation systems ,Energy saving potential ,Guidelines ,Visual assessment ,Decision making - Abstract
This report is one of five deliverables related to WP6 ‘Development and evaluation of guidelines and web-based preliminary assessment tool‘. The prime objective of WP6 is to develop and to assess written and web-based guidelines and a web tool (including a feasibility study of possible input and output data) for renovation of historic buildings with internal insulation. This deliverable contains the written guidelines, referring to Task 6.1, consisting of a guideline for setting the goal of applying internal insulation (Section 3), a guideline for deciding whether a building is suitable for internal insulation (Section 4), a guideline for selecting an internal insulation system (Section 5) and a guideline for evaluating the energy saving potential and the environmental impact (Section6). The written guidelines are also made accessible through a web-site, described in deliverable D6.3.
- Published
- 2020
7. Written guidelines for decision making concerning the possible use of internal insulation in historic buildings
- Author
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Blumberga, Andra, Freimanis, Ritvars, Blumberga, Dagnija, Veidenbergs, Ivars, Hansen, Ernst Jan De Place, Hansen, Tessa Kvist, Du, Guangli, Stöcker, Eric, Sontag, Heike, Freudenberg, Peggy, Janssen, Hans, Roels, Staf, di Giuseppe, Elisa, D'Orazio, Marco, Gianangeli, Andrea, Maracchini, Gianluca, Quagliarini, Enriro, Møller, Eva B., Capener, Carl-Magnus, Lång, Lukas, Johansson, Pernilla, Lasvaux, Sebastien, Giorgi, Morgane, Favre, Didier, Padey, Pierryves, and Wagner, Guy
- Subjects
Insulation systems ,Energy saving potential ,Guidelines ,Visual assessment ,Decision making - Abstract
This report is one of five deliverables related to WP6 ‘Development and evaluation of guidelines and web-based preliminary assessment tool‘. The prime objective of WP6 is to develop and to assess written and web-based guidelines and a web tool (including a feasibility study of possible input and output data) for renovation of historic buildings with internal insulation. This deliverable contains the written guidelines, referring to Task 6.1, consisting of a guideline for setting the goal of applying internal insulation (Section 3), a guideline for deciding whether a building is suitable for internal insulation (Section 4), a guideline for selecting an internal insulation system (Section 5) and a guideline for evaluating the energy saving potential and the environmental impact (Section 6). The written guidelines are also made accessible through a web-site, described in deliverable D6.3.
- Published
- 2020
8. Monitored conditions in wooden wall plates in relation to mold and wood decaying fungi
- Author
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Hansen, Tessa Kvist, Jensen, Nickolaj Feldt, Møller, Eva, Hansen, Ernst Jan De Place, and Peuhkuri, Ruut Hannele
- Abstract
In historic masonry buildings, wood can be embedded in the walls as storey partition beams, or as supportive wall plates. Half-timbered masonry constructions, or wooden frames, e.g. combined with internal insulation, are other examples of wooden elements. Wood decaying fungi can cause serious damage to wood, which may lose mass and strength, ultimately yielding the risk of collapse. In addition, some fungal species may even be hazardous for occupants. All wood decaying fungi depend on favorable moisture and temperature conditions, although the threshold conditions may vary with various fungal species and types, and state of the wood. To predict the risk of occurrence of wood rot, several models have been developed, however most of these are based on a limited number of experiments, or very specific cases. For these reasons, the applicability of the models to other scenarios (fungal species, wood species) may not be appropriate. Furthermore, another failure mode for wood and moisture, is mold growth, which is initiated at lower moisture levels. An indication of risk of mold growth would indicate problems or risks before the initiation of wood rot. Mold growth does not deteriorate the wood, but is usually equally undesired due to health concerns of occupants. For this reason, there might be places where some mold growth would be acceptable, e.g. embedded beam ends if there is no transfer of air from the moldy area to the indoor air. Therefore, risk of rot could be important. The paper investigates models for mass loss due to wood decay and mold growth based on exposure time to favorable hygrothermal conditions. The investigation is based on inspection of wood samples (wall plates) from a full-scale experimental setup of masonry with embedded wood and monitored conditions, to which the prediction models will be applied. Monitored hygrothermal conditions were implemented in mold and wood decay models, and samples were removed from the test setup. The implemented models yielded high mold index and mass loss, whereas neither mold nor decay was observed in the physical samples. Results indicate that the implemented models, in these cases appear to overestimate the risks of mold and rot in the supportive lath behind the insulation.
- Published
- 2020
9. Retrofit of Masonry in Historic Buildings:Role of Climatic Loads and Material Parameters
- Author
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Hansen, Tessa Kvist, Peuhkuri, Ruut Hannele, and Bjarløv, Søren Peter
- Abstract
Historical buildings represent cultural, historic and aesthetic value, whether preservation worthy or not. For this reason, the concept of internal insulation has been introduced as a possible energy retrofitting measure for such buildings. The application of the thermal insulation on the interior side of the wall reduces the heating energy consumption and improves the thermal comfort. But it also changes the hygrothermal conditions of that wall reducing the drying potential and leaving the original wall colder and damper when compared to pre-retrofitting. This may lead to undesired consequences like interstitial condensation, mold growth, wood rot and the general deterioration of the façade materials and components. The prediction of the hygrothermal performance of internal insulation solutions plays therefore an important role when designing successful retrofit measures. External loads, e.g. wind driven rain (WDR) and solar radiation, may vary largely depending the location and orientation and have a significant impact especially on historic buildings with porous masonry walls. This paper presents a simulation study for assessment of the hygrothermal performance of internally insulated historic masonryunder given conditions. A monitored case study made up the basis for this study that primarily focuses on the influence of orientation, indoor climate, façade color and brick type with regard to WDR, investigated through dynamic hygrothermal simulations. The results show that high loads from WDR inevitably increased the moisture content of the wall, but also certain material parameters and orientation, including solar radiation in combination with WDR play a role. Historical buildings represent cultural, historic and aesthetic value, whether preservation worthy or not. For this reason, the concept of internal insulation has been introduced as a possible energy retrofitting measure for such buildings. The application of the thermal insulation on the interior side of the wall reduces the heating energy consumption and improves the thermal comfort. But it also changes the hygrothermal conditions of that wall reducing the drying potential and leaving the original wall colder and damper when compared to pre-retrofitting. This may lead to undesired consequences like interstitial condensation, mold growth, wood rot and the general deterioration of the façade materials and components. The prediction of the hygrothermal performance of internal insulation solutions plays therefore an important role when designing successful retrofit measures. External loads, e.g. wind driven rain (WDR) and solar radiation, may vary largely depending the location and orientation and have a significant impact especially on historic buildings with porous masonry walls. This paper presents a simulation study for assessment of the hygrothermal performance of internally insulated historic masonryunder given conditions. A monitored case study made up the basis for this study that primarily focuses on the influence of orientation, indoor climate, façade color and brick type with regard to WDR, investigated through dynamic hygrothermal simulations. The results show that high loads from WDR inevitably increased the moisture content of the wall, but also certain material parameters and orientation, including solar radiation in combination with WDR play a role.
- Published
- 2019
10. Threshold values for failure, linked to types of building structures and failure modes
- Author
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Johansson, Pernilla, Lång, Lukas, Capener, Carl-Magnus, Møller, Eva B., Quagliarini, Enrico, D'Orazio, Marco, Gianangeli, Andrea, Janssen, Hans, Feng, Chi, Langmans, Jelle, Feldt Jensen, Nickolaj, de Place Hansen, Ernst Jan, Peuhkuri, Ruut Hannele, and Hansen, Tessa Kvist
- Abstract
This report comprises a study of material threshold values, failure modes and related failure prediction models to enable an evaluation of adding internal insulation in historic brick buildings. Threshold values and prediction models have been investigated both within literature and through laboratory study, by for instance comparing prediction models to real field results and by testing threshold values in laboratory. The aim of this report is to find threshold values and suitable and reliable prediction models to be included in the decision guidelines and the web tool, which are the final outcomes of the RIBuild project. Failure modes included in the report are mould growth on building materials, rot and wood decay, frost damage and discoloration of facades. This report comprises a study of material threshold values, failure modes and related failure prediction models to enable an evaluation of adding internal insulation in historic brick buildings. Threshold values and prediction models have been investigated both within literature and through laboratory study, by for instance comparing prediction models to real field results and by testing threshold values in laboratory. The aim of this report is to find threshold values and suitable and reliable prediction models to be included in the decision guidelines and the web tool, which are the final outcomes of the RIBuild project. Failure modes included in the report are mould growth on building materials, rot and wood decay, frost damage and discoloration of facades.
- Published
- 2019
11. RIBuild Deliverable no. D2.2 – Threshold values for failure, linked to types of building structures and failure modes
- Author
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Johansson, Pernilla, Lång, Lukas, Capener, Carl-Magnus, Møller, Eva B., Quagliarini, Enrico, D’Orazio, Marco, Gianangeli, Andrea, Janssen, Hans, Feng, Chi, Langmans, Jelle, Jensen, Nickolaj Feldt, de Place Hansen, Ernst Jan, Peuhkuri, Ruut Hannele, and Hansen, Tessa Kvist
- Subjects
algae ,laboratory testing ,mold ,threshold values ,frost ,fungi ,rot ,predictive models ,cyanobacteria ,failure modes - Abstract
This report comprises a study of material threshold values, failure modes and related failureprediction models to enable an evaluation of adding internal insulation in historic brick buildings.Threshold values and prediction models have been investigated both within literature and throughlaboratory study, by for instance comparing prediction models to real field results and by testingthreshold values in laboratory. The aim of this report is to find threshold values and suitable andreliable prediction models to be included in the decision guidelines and the web tool, which are thefinal outcomes of the RIBuild project. Failure modes included in the report are mould growth onbuilding materials, rot and wood decay, frost damage and discoloration of facades.
- Published
- 2019
12. Energy Efficient Comfort in Older Apartment Blocks: Results and Experience
- Author
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Harrestrup, Maria, Hansen, Tessa Kvist, Haferbier, Rune, Lange, Jørgen, Pedersen, Leif Rønby, and Karkov, Rasmus
- Published
- 2016
13. The effects of wind-driven rain on the hygrothermal conditions behind wooden beam ends and at the interfaces between internal insulation and existing solid masonry.
- Author
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Hansen, Tessa Kvist, Bjarløv, Søren Peter, and Peuhkuri, Ruut
- Subjects
- *
WOODEN beams , *MASONRY , *HISTORIC buildings , *BUILDING design & construction , *HYGROTHERMOELASTICITY , *MOISTURE measurement , *EFFECT of earthquakes on buildings - Abstract
• Wind-driven rain (WDR) quantification experimentally on 2 case buildings. • Effect of WDR on hygrothermal conditions in internally insulated masonry studied. • Numerical simulations to determine WDR effect on hygrothermal performance. • WDR models were found to overestimate WDR deposition. • Direct influence of WDR events on RH behind insulation was not detected. An inevitable measure when energy retrofitting historic buildings in Europe, is the reduction of building envelope heat loss. On preservation-worthy facades where external insulation is not an option, installation of internal insulation is gaining pace. The historic buildings in Denmark are often constructed with solid masonry facades and wooden decks. The internal insulation may, however, entail potential hygrothermal risks in walls and embedded wood. Measures such as vapour barriers and capillary active insulation materials are continuously evolving and the subject of much current research. The hygrothermal conditions are of great importance for the durability of the building constructions, and for the health and wellbeing of occupants. Wind-driven rain (WDR) is a central factor contributing to water penetration and moisture loads of the exterior walls. Numerous studies have shown that WDR loads influence the moisture conditions in masonry walls and embedded wooden beams, and can even affect interior relative humidity. In the present paper WDR loads on existing façades in a cold temperate climate were determined by measurements and compared to a semi-empirical model. Simultaneously, the hygrothermal conditions within internally insulated walls with exposed brick and embedded wooden beams were monitored. Furthermore, numerical simulations were implemented for clarification of WDR impact. Hygrothermal simulations and previous studies, inevitably show that high WDR loads result in higher moisture content behind the interior insulation. Results from the field measurements of WDR however, cannot directly be referred to the moisture content measured in walls behind interior insulation or beam ends. However, fluctuations in external air humidity proved to be influential on condiditons in the construction. Implementation of a semi-empirical model for calculations of WDR agreed with previous studies in predictions being too conservative when compared to measured WDR. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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