1. |
- Alev, Uellar, et al.
(författare)
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Indoor hygrothermal condition and user satisfaction in naturally ventilated historic houses in temperate humid continental climate around the Baltic Sea
- 2016
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Ingår i: Architectural Science Review. - : Informa UK Limited. - 0003-8628 .- 1758-9622. ; 59:1, s. 53-67
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Tidskriftsartikel (refereegranskat)abstract
- Indoor climate and user satisfaction were analysed by field measurement and a questionnaire in 67 traditional rural houses in Estonia, Finland and Sweden. Our findings showed that the indoor climate in all the investigated historic rural houses needs improvement. The room temperature was mainly too low during winter. Leaky houses had also a larger vertical temperature difference. The relative humidity in the unheated and periodically heated houses was high during winter and caused risk for mould growth in 17% of all houses and 33% of unheated houses. Significant differences of indoor humidity loads in different houses were revealed depending on the living density and usage profile. During the winter period, the design value of moisture excess was 4-5g/m(3) and the average moisture load was 2-3.5g/m(3). The indoor humidity load in historic houses was similar to that in modern houses. The results of the questionnaire showed that main problems were related to unstable or too low temperatures. At the same time, inhabitants rated the overall indoor climate as healthy and no statistically important relations were found between average indoor temperature and complaints about too cold or too warm indoor temperatures.
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2. |
- Alev, Ullar, et al.
(författare)
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Renovation alternatives to improve energy performance of historic rural houses in the Baltic Sea region
- 2014
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 77, s. 58-66
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Tidskriftsartikel (refereegranskat)abstract
- This paper analyses renovation alternatives to improve energy performance of historic rural houses in three countries (Estonia, Finland, Sweden) in the Baltic Sea region (cold climate). The study was conducted by a combination of field measurements and simulations. Indoor climate, typical houses and structures as well as the current condition and need for renovation were determined by field measurements. Based on field measurements, indoor climate and energy simulation models were validated and used to calculate energy use for different renovation measures. Energy renovation packages were calculated for different scenarios (minimal influence on the appearance of the house, improvement of thermal comfort, improvement of building service systems) for different energy saving levels. The analysis showed that the improvement of building service systems and the energy source holds the largest energy saving potential. The building envelope of old rural houses needs improvement also due to high thermal transmittance and air leakage. The insulation of the external wall has the largest single energy saving potential of the building's envelope. The results show how energy savings depend on energy saving targets, typology of the building, thermal transmittance of original structures, and building service systems. (C) 2014 Elsevier B.V. All rights reserved.
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3. |
- Altahr-Cederberg, Camilla, et al.
(författare)
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Vad tänker du på, när jag säger energieffektivisering i kulturhistoriskt värdefulla byggnader?
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten innehåller en sammanställning av intervjuer med byggnadsantikvarier på länsstyrelser och stift angående energieffektivisering i kulturhistoriskt värdefulla byggnader. Intervjuerna har utförs inom ett projekt på RAÄ som bedrivs inom forskningsprogrammet Spara och Bevara, energieffektivisering i kulturhistoriskt värdefulla byggnader, som finansieras av Energimyndigheten, Riksantikvarieämbetet och Svenska kyrkan.
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4. |
- Arumägi, Endrik, et al.
(författare)
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Indoor climate in a naturally ventilated unheated medieval church in Harju-Risti, Estonia
- 2010
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Ingår i: 10th REHVA World congress Clima 2010.
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Konferensbidrag (refereegranskat)abstract
- Indoor climate in a naturally ventilated unheated medieval church was analysed to determine if the conditions existing suit for three medieval wooden sculptures forming the Calvary group that were decorated the church until 1958. The values of temperature and RH were measured with data loggers at 1-h intervals inside and outside the church. Ventilation measurements were performed using a passive tracer gas technique. The current study shows that there is a considerable risk in bringing back the medieval sculptures forming the Calvary group to the Harju-Risti Church without creating conditions for indoor temperature and humidity regulation. To start risk assessment it is required to maintain a RH level that prevents the risk of mould growth, reduce fluctuations of air RH annually and in the short term period, avoid of too high and too low humidity levels in church that could cause flaking, peeling and cracking of wooden sculptures.
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5. |
- Balksten, Kristin, et al.
(författare)
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Increased use of ruins through secured masonry and comfortable climate
- 2010
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Ingår i: Proceedings of the 7th International Conference on Science and Technology in Archaeology and Conservation, Petra, Jordan.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a unique scientific research project, funded by the KK-foundation in Sweden together with several companies participating in the project. A primary goal is to find methods to examine and take care of open masonry constructions thereby enabling an increased use of them in a safe and comfortable way without diminishing their cultural values. A second goal is to establish a long-term cooperation/network of researchers, conservators, engineers, antiquarians and craftsmen that can keep and develop the knowledge. The project takes place in year 2010 and 2011. This paper presents a model of cooperation as well as the ongoing experiment and expected results. The project is divided into three major parts:1) Description and assessment of historic masonry as load bearing structures. 2) Assessment of stone and mortar in old masonry and finding the methods to secure and preserve them. 3) The climate in the ruin with respect to comfort and preservation. The goals for the different parts of this research project are to find the best possible solutions of how to: a) Evaluate the construction of complex masonry structures to enable new additions that are appropriate with respect to statics. b) Find efficient methods to evaluate and conserve the status of the materials (stone, mortar) and walls in old masonry to grant safe accessibility. c) Create a comfortable climate in an open masonry structure without closing it. These three research areas all focus on the historic masonry which at the same time forms the climate shell, the bearer of plaster and the historical setting to the activities that are to take place in the ruin.
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6. |
- Balksten, Kristin, 1977-
(författare)
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Kalkputs : porstrukturens betydelse för beständighet
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- When restoring historic lime plaster it can be difficult to reach the required durability. Today newly made lime plaster can fall off due to frost damages after only a couple of winters. To understand and solve these problems, the subject has been studied from different perspectives. Several factors in the production step are making an influence on the durability of lime plaster: 1. A binder, suitable for the building, must be chosen along with sandthat gives good material properties in both fresh mortar and in plasters. 2. The lime/sand ratio and the mixing technique should be chosen from the properties in the lime and the sand, in order to get a mortar with good workability. 3. The craftsmanship should be adjusted to the mortar, the weather and the underlying materials. A plaster with good frost resistance has a certain pore structure. The plaster should have some round air pores that contain air even when the material is filled capillary with water. Such air pores give the water a free space to expand when it is freezing. If the air pores are missing, the ice crystals may damage the plaster when expanding. To increase the chance of making a frost resistant lime plaster, the lime/sand ration must be adjusted so the lime can fill up well in the sand. Otherwise a collapsed pore system can easily occur, which means an open pore system without distinct air pores. A collapsed pore system contains many pores well connected with each other. Such a system is easily damaged by frost. To increase the chance of success, it is of great importance to work the surface of the lime plaster at the right time and in the correct way. Before working on a surface the mortar must be aloud to stiffen. Only then a homogeneous material can be created; cracks due to shrinkage can be pressed together and the result is a more compact material with an open surface. The time necessary for mortars to stiffen is related to the water content of the mortar, the suction of the underlying surface and the weather conditions. If the surface is worked on while the mortar is still fresh, the binder can form a hard lime shell on the surface. Inside thematerial a lack of binder can appear. Such plasters have a very low frost resistance. Other durability problems related to plaster are damages in the underlying materials, i.e. rotten wood in covered constructions or leached lime in old joints. Such damages can occur if the covering mortar is made of strong hydraulic lime or cement, since they form plasters with a low permeability in comparison to lime. Due to mentioned findings, it is important to study how a pore structureis influenced by materials, mixture and craftsmanship. Only then it is possible to understand how damages can be decreased.
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7. |
- Balksten, Kristin, 1977-, et al.
(författare)
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Permeability in lime plaster in relation to durability of covered materials
- 2004
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Ingår i: Proceedings of the 32nd IAHS World Congress on Housing Sustainability of the Housing Projects. Trento, Italy 2004.. ; 1
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Konferensbidrag (refereegranskat)abstract
- In restoration of old buildings, lime plasters are used for reasons of authenticity and for technicalreasons as well. In many traditional constructions, there is wood behind the plasters or there is old limemortar in the masonry. For the durability of both these underlying materials, it is important that therelative humidity, RH is not too high under a long time of exposure. This can lead to an accelerateddegradation process of wood and leaching of lime in mortars. To prevent this, the plaster must have aproper permeability.The permeability of a material determines its ability to transport gas and moisture. In lime plasters,permeability affects hardening, carbonation as well as durability of the underlying materials. In thepresent paper, eleven mixtures of lime mortar were studied. The binders used were lime slaked in fourdifferent ways, hydraulic lime and cement.The following measurements were made to analyse the permeability and the pore structure of thesamples. Gas permeability and draining curves give an indication of rate of carbonation. Vapourpermeability shows the ability of plaster to transmit moisture at different RH. Thin sections were madefor microscopically investigations of the samples.The investigations show that both the vapour permeability and gas permeability decreases with anincreased amount of hydraulic binder in the lime plasters. Even small amounts of hydraulic binderhave a significant effect.By connecting these results with examples from reality, the picture becomes clearer. In the medievaltown Visby in Sweden, there are several examples of both rotten wood and disintegrated lime mortars.It is constructions from 13th to 19th centuries and low permeable cementitious plasters have coveredthem all, during the middle of the 20th century.
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8. |
- Balksten, Kristin, 1977-
(författare)
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Traditional lime mortar and plaster : Reconstruction with emphasis on durability
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lime mortar and plaster have been investigated with the aim to improve the knowledge on how to make them as durable as before the cement technology was developed. The background was the durability problems experienced for newly produced lime plaster on the medieval churches on the island of Gotland, Sweden. In some cases the new lime plaster façades showed severe frost damages after only one winter. Although the lime was burnt and produced according to old local traditions, the lime mortar was still mixed and worked onaccording to methods developed for lime-cement mortar. This often led to a very porous lime plaster with a lime shell in the surface and such a plaster has been shown to be sensitive to frost expansion. Field studies were combined with laboratory studies of thin section specimens. Optical microscopy and scanning electron microscopy have been important analytical methods showing the porosity and the structure of the binder and aggregate materials. The investigations have been carried out on both historic and on newly made reference mortar and plaster. The field studies were carried out mainly on Gotland, using local materials. The influence of the raw materials, i.e. lime, aggregate and blending ratio was investigated. The focus has been on the workability of the fresh mortars as well as the pore structure of the carbonated plaster. The craftsmanship, meaning mixing and application of mortar and working the plaster surface, was studied in order to clarify its final pore structure. The pore structure in a material determines many of its technical properties, such as moisture transportation, compressive strength, permeability and frost resistance. All these properties are closely connected to the durability of the mortar and plaster. The permeability of the plaster has an impact also on the durability of the covered construction materials. Behind low-permeable plasters made with hydraulic binder, examples of extensive damages of rotten wood and leached lime have been shown. The investigations have shown the importance of choosing a mortar adjusted to the building construction. They also showed the importance of choosing a blending ratio adjusted to the specific binder and sand used in order to get a mortar with a suitable pore structure and good durability. It has also shown the importance of knowing when and how to work on the plaster surface in order to obtain a homogenous material that is well receptive for lime wash and has a good frost resistance. The combination of all the investigations has led to a method for reconstructing historic mortar and plaster with good durability.
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9. |
- Berg, Fredrik, et al.
(författare)
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User-driven energy efficiency in historic buildings : A review
- 2017
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Ingår i: Journal of Cultural Heritage. - : Elsevier BV. - 1296-2074 .- 1778-3674. ; 28, s. 188-195
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Forskningsöversikt (refereegranskat)abstract
- The paper draws from the general literature on energy efficiency and historic buildings to explain the importance and potential of user-driven energy efficiency in historic buildings. It is the first review that places the user as a central object of study in the research field of historic buildings and energy efficiency. Relevant interdisciplinary topics and research results that make up the core of the field are presented and discussed in relation to user behaviour and its impact on energy consumption. The paper also investigates how user behaviour aspects can be integrated in a procedural approach to energy refurbishment in historic buildings. Research and experience from the building stock in general clearly shows how a user's awareness and behaviour, such as choice of temperature, zone heating and controlled airing, can have a significant effect on energy demand yet have no physical impact on the building. However, this has not received enough attention with regards to the historic building stock, where many physical energy efficiency measures can have negative impacts on the historic qualities of the building. Modification of user behaviour can therefore be a way not only to reduce energy demand but also to minimise the physical impact of increasing energy efficiency on historic buildings. The paper concludes that the current research agenda on historic buildings and energy efficiency has broken much ground but remains focused more on technical solutions than bottom-up user perspectives. Two main topics are identified as key barriers and future research fields: First, energy performance modelling is identified as a general barrier to developing sustainable strategies that promote user impact in historic buildings. Accurate energy modelling of historic buildings is a complex field reliant on the thermal interplay between user-building and building-district. Improved knowledge and intensified research is necessary to avoid distorted energy modelling results and unwanted rebound effects. Practical tools also require that the modelling can be used for trade-off scenarios where other sustainability aspects such as cultural heritage and economy are weighed in. Second, awareness raising in order to foster a deeper understanding and knowledge about the construction, system and cultural heritage values of a building is proposed as a key ingredient and driver for improved and sustainable energy behaviour. The paper argues that while user-driven energy efficiency represents an important resource for fostering less energy-demanding and less intrusive interventions in historic buildings, there are no guarantees for achieving the planned level of energy efficiency without taking into account user behaviour and the actual operation and energy performance of the historic building. To do this without risking negative consequences, improved decision-making processes are needed on policy, building and user level. An interdisciplinary bottom-up approach to energy refurbishment is presented. The essence of the model is that users and residents should always play a central role in the decision-making process because the well-being of the historic building will always depend on its day-to-day users, and vice versa.
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10. |
- Broström (red), Tor, et al.
(författare)
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Brandsäkerhet för byggnader med kulturvärden: En kunskapsöversikt
- 2021
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Abstract [sv] Arbetet med brandsäkerhet för byggnader med kulturvärden kräver anpassade lösningar som också kan tillgodose ett bevarande av byggnaderna och deras kulturvärden. Det finns, utspritt, mycket kunskap och erfarenhet inom det här området både i Sverige och internationellt. För att tillgodose ett behov av samlad kunskap inom detta område initierade Brandforsk en kunskapsöversikt tillsammans med Akademiska hus, Fortifikationsverket, Kammarkollegiet, Kyrkans försäkring, Riksantikvarieämbetet och Statens fastighetsverk. Den här kunskapsöversikten syftar till att sammanställa och presentera den kunskap som finns. Ett kompletterande syfte är att definiera områden där kunskap saknas. Kunskapsöversikten är indelad i sex områden: 2. Skydd mot brands uppkomst 3. Spridning av brand inom byggnad 4. Spridning av brand till byggnad 5. Brandens påverkan på byggnadens stomme 6. Utrymning 7. Räddningstjänstens insats Med utgångspunkt från workshops har en sammanställning av behovsbilden gjorts. Kunskapsöversikten och behovsbilden ligger till grund för en gap-analys vilken pekar på behov av fortsatt forskning och utveckling. Abstract [en] Working with fire safety in historic buildings requires adapted solutions that can also satisfy the preservation of the buildings and their cultural values. There is a lot of knowledge and experience in this area both in Sweden and internationally. In order to make this available to end users, Brandforsk initiated a literature review together with a group of national sponsors. This literature review aims to compile and present the documented knowledge in the field. A complementary purpose is to define knowledge gaps. The review is divided into six areas: 2. Fire prevention 3. Fire spread within buildings 4. Fire spread between structures 5. Structural fire resistance 6. Evacuation 7. Fire and rescue service activities Based on workshops the needs of end users have been compiled. A comparison of the outcome of the review and the end user needs defines a knowledge gap pointing to the need for continued research and development.
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