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Article

Aitor Erkoreka, Ivan Flores-Abascal, Cesar Escudero, Koldo Martin, Jose Antonio Millan and Jose Maria Sala

Understanding the dynamic hygrothermal behavior of building elements is very important to ensure the optimal performance of buildings. The Laboratory for Quality Control…

Abstract

Purpose

Understanding the dynamic hygrothermal behavior of building elements is very important to ensure the optimal performance of buildings. The Laboratory for Quality Control in Buildings of the Basque Government tested a flat roof designed by a construction company that developed a building to be constructed using prefabricated modules. This is a five to eight floor building with ventilated façade and a flat roof covered by gravel with the possibility of changing it to a green cover. The paper aims to discuss this issue.

Design/methodology/approach

The interest of this research was threefold. The first objective was to accurately test, under real dynamic weather conditions, the roof design in a PASLINK test cell to obtain the U-value and the thermal capacitance of the different roof layers, and of the roof as a whole, through the precise calibration of resistance-capacitance mathematical models of the roof. Based on the parameters and experimental information of these calibrated models, a second goal was to calibrate and validate a Wufi model of the roof.

Findings

This second calibrated model was then used to simulate the dynamic hygrothermal behavior of the roof, obtaining the roof’s hourly thermal demand per square meter for a whole year in different locations considered in the Spanish Building Code. These simulations also permitted the authors to study the risk of condensation and mold growth of the tested component under different climatic conditions.

Originality/value

The successful combination of the PASLINK method to calibrate the Wufi hygrothermal model is the main novelty of this research.

Details

International Journal of Building Pathology and Adaptation, vol. 38 no. 1
Type: Research Article
ISSN: 2398-4708

Keywords

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Article

Mohammadjavad Mahdavinejad, Kavan Javanroodi and Leyli Hashemi Rafsanjani

The purpose of this paper is to investigate moisture problems and defects which have been caused by condensation in historic buildings. Emphasis has been put on finding…

Abstract

Purpose

The purpose of this paper is to investigate moisture problems and defects which have been caused by condensation in historic buildings. Emphasis has been put on finding condensation possibility on the external walls and inside temperature and humidity.

Design/methodology/approach

A third-part study including survey method to identify moisture problems and exhaustion, then determining indoor and outdoor temperature and relative humidity in a two-part survey within four days periods, and finally computer modeling and simulation to finding condensation possibility in the building walls by WUFI and THERM software.

Findings

Results indicated that the case study has serious defects and almost 7.5°C differences (Δt) and about 6 percent relative humidity differences (Δh) between indoor and outdoor temperature, and from analyzing computer simulations, condensation risk occurrence between wall layers is witnessed. Also this study shows that some climatic methods applied by traditional architects despite enhancing thermal comfort have caused damages and defects to the building envelope and structure. In this paper, the authors suggest a method to reduce condensation possibility by active ventilation for reducing temperature differences.

Originality/value

While there is a lock of technical researches and investigations about architectural heritages conservation, this study tries to perform a technical research and filling the gaps in this subject area.

Details

World Journal of Science, Technology and Sustainable Development, vol. 10 no. 4
Type: Research Article
ISSN: 2042-5945

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Article

J.M.P.Q. Delgado, V.P. de Freitas, A.S. Guimarães and C. Ferreira

Crawl space ventilation became essential to avoid moisture damage. Historical houses with wood floor and crawl spaces unventilated correctly often face problems of…

Abstract

Purpose

Crawl space ventilation became essential to avoid moisture damage. Historical houses with wood floor and crawl spaces unventilated correctly often face problems of biological degradation. This paper seeks to address these issues.

Design/methodology/approach

In this work a case study of the Egas Moniz museum house, in Estarreja, Portugal, with different building pathologies, such as biological degradation and development of micro‐organisms and fungi, is presented. An experimental campaign was carried out with continuous monitoring of the relative humidity and temperature, to validate the real climatic conditions in the crawl spaces. Additionally, the authors analyse the treatment technologies used in the past and the characteristics of the rehabilitation solutions in order to control the hygrothermal behaviour. Simultaneously, numerical simulation was done using the software tool WUFI‐2D to simulate the hygrothermal building behaviour and a sensitivity study of parameters used was done.

Findings

The in‐situ experimental results showed that high values of relative humidity imply biological degradation of the wood floor and the numerical and analytical models used showed the same tendency. The numerical results showed the importance of crawl spaces with a good ventilation to avoid mould growth and, also, suggested that controlled mechanical ventilation is preferable to strongly continuous mechanical ventilation in this type of spaces. The experimental study shows that the continuous functioning of a ventilation system may lead to the occurrence of interior condensation, so a hygro‐regulated system is thus essential to control unwanted condensation, with an appropriate functioning criterion.

Practical implications

In accordance with the numerical and experimental results, the authors proceeded to the implementation of a hygro‐regulated system to ventilate the crawl spaces of the Egas Moniz museum house.

Originality/value

This paper presents a new proposed intervention methodology, in crawl spaces, to avoid mould growth, based on an extraction controlled by a hygro‐regulated ventilator.

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Article

Philipp Kölsch

The surface temperature of the sub-roof beneath the ventilation layer and the tiles is one of the most important factors for the hygrothermal performance of pitched roofs…

Abstract

Purpose

The surface temperature of the sub-roof beneath the ventilation layer and the tiles is one of the most important factors for the hygrothermal performance of pitched roofs. The air layer between tiles and sub-roof and the air exchange with the outdoor air influence the heat transfer and therefore affect the moisture level inside the roof construction. The paper aims to discuss these issues.

Design/methodology/approach

This paper provides the results of a research project performed at Fraunhofer-Institute for Building Physics, based on field test results. The investigations analyze the thermal behavior of different vented and ventilated roof constructions.

Findings

It was found that for a detailed model with roof cladding and ventilated air layer normally too many parameters are unknown. For that reason a simplified approach was set up, especially to consider the radiation exchange between the tiles and the underlay as well as the effects of the ventilation.

Originality/value

Now, effective surface transfer parameters can substitute both cladding and air layer in the simulation, while the approach still provides a high accordance with the measured values. The paper provides characteristic values for different roofing situations to simulate ventilated roofs by means of hygrothermal simulation in a simplified way.

Details

International Journal of Building Pathology and Adaptation, vol. 37 no. 4
Type: Research Article
ISSN: 2398-4708

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Article

Christoph Morbitzer

This article reviews the development of low energy and sustainable housing in the UK and Germany. It illustrates that despite their close geographical proximity…

Abstract

This article reviews the development of low energy and sustainable housing in the UK and Germany. It illustrates that despite their close geographical proximity substantially different approaches have been applied in the two countries in the pursuit of an energy efficient, domestic built environment.

The article describes and compares the German Passivhaus and the UK Code for Sustainable Homes, both important drivers for low energy housing. It also relates them to two project examples, the ‘Energieautarkes Haus’ (energy independent house) in Freiburg and the BeDZED project near London.

A main conclusion from the article is that Germany has developed with the Passivhaus a design concept that holds a considerable potential to reduce the energy consumption of the UK housing sector, and points out the surprisingly limited uptake so far. It however also emphasises the ability of the UK to apply a holistic building design approach, and points out that the UK has developed with BREEAM and the Code for Sustainable Homes a framework that directs the flow of activity in the pursue of buildings with a low environmental impact.

Finally, the article emphasises the need for better collaboration between different countries.

Details

Open House International, vol. 33 no. 3
Type: Research Article
ISSN: 0168-2601

Keywords

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Article

Cormac Flood and Lloyd Scott

The residential sector in Ireland accounted for 25 per cent of energy related CO2 emissions in 2016 through burning fossil fuels, a major contributor to climate change. In…

Abstract

Purpose

The residential sector in Ireland accounted for 25 per cent of energy related CO2 emissions in 2016 through burning fossil fuels, a major contributor to climate change. In support of Ireland’s CO2 reduction targets, the existing housing stock could contribute greatly to the reduction of space-heating energy demand through retrofit. Approximately 50 per cent of Ireland’s 2m dwellings pre-date building regulations and are predominantly of cavity and solid wall construction, the performance of which has not been extensively investigated at present. Although commitment to thermal upgrade/retrofit of existing buildings may increase under future government policies, the poor characterisation of actual thermal performance of external walls may hinder the realisation of these targets. Thermal transmittance (U-values) of exterior walls represents a source of uncertainty when estimating the energy performance of dwellings. It has been noted in research that the standard calculation methodology for thermal transmittance should be improved. Implementing current U-value calculation methods may result in misguided retrofit strategies due to the considerable discrepancies between in situ measurements and calculated wall U-values as documented in the case studies carried out in this research. If the method of hygrothermal analysis were to be employed as a replacement for the current standard calculation, it could have significant implications for policy and retrofit decision making. The paper aims to discuss this issue.

Design/methodology/approach

This research project analysed a case study situated in Dublin, Ireland. The case studies offer an account of the in situ thermal transmittance of exterior walls and link these to hygrothermally simulated comparisons along with more traditional design U-values.

Findings

The findings of this research identify discrepancies between in situ and design U-values, using measurement, hygrothermal simulation and standard method U-value calculations. The outcomes of the research serve as an introduction to issues emanating from a larger research project in order to encourage researchers to understand and further explore the topic.

Originality/value

It has previously been highlighted that moisture content is linked to the increase in thermal conductivity of building materials, thus reducing the thermal effectiveness and increasing the elemental U-value. Therefore, it is vital to implement reliable prediction tools to assess potential thermal performance values. This paper presents the findings of a critical instance case study in Dublin, Ireland in which an existing west facing external wall in a semi-detached dwelling was analysed, simulated and measured to verify the elemental wall assembly and quantify thermal transmittance (U-value) incorporating the major criteria required for building performance simulation.

Details

International Journal of Building Pathology and Adaptation, vol. 38 no. 1
Type: Research Article
ISSN: 2398-4708

Keywords

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Article

Sara Stingl de Freitas and Vasco Peixoto de Freitas

The purpose of this paper is to present a case study of cracks on external thermal insulation composite systems (ETICS) along the thermal insulation joints and the…

Abstract

Purpose

The purpose of this paper is to present a case study of cracks on external thermal insulation composite systems (ETICS) along the thermal insulation joints and the information available on the building pathology catalogue – PATORREB. The aim is to establish the methodology to study the cause of the pathology observed on a building which is located on the interior of Portugal based on in situ probing together with the analysis of hygrothermal and mechanical behaviour.

Design/methodology/approach

An in situ analysis was performed to assess the causes. The hygrothermal dynamic behaviour of the wall was analysed with a numerical simulation advanced tool considering the climatic conditions, the characteristics of the thermal insulation plates as well as the support and finishing layer properties. Moreover, a qualitatively analysis of the mechanical behaviour, based on the bonding process, thermal insulation and exterior rendering properties was performed.

Findings

It was concluded that the insulation properties – thermal expansion coefficient and stiffness, the thermal expansion coefficient of the exterior rendering, together with adverse climatic conditions were critical for the appearance of cracks along the plate joints, particularly with spot bonding. The expansion and retraction stresses and the restrained movements of the components can result in bending moments, especially when the insulation material has a high stiffness value, which will create the crack on the rendering system.

Originality/value

A combination between a hygrothermal and mechanical analysis of an ETICS pathology concerning the appearance of cracks with a subsequent integration into a building pathology catalogue.

Details

Structural Survey, vol. 34 no. 1
Type: Research Article
ISSN: 0263-080X

Keywords

Abstract

Details

International Journal of Building Pathology and Adaptation, vol. 37 no. 4
Type: Research Article
ISSN: 2398-4708

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Article

Sofie Pelsmakers, Evy Vereecken, Miimu Airaksinen and Cliff C.A. Elwell

Millions of properties have suspended timber ground floors globally, with around ten million in the UK alone. However, it is unknown what the floor void conditions are…

Abstract

Purpose

Millions of properties have suspended timber ground floors globally, with around ten million in the UK alone. However, it is unknown what the floor void conditions are, nor the effect of insulating such floors. Upgrading floors changes the void conditions, which might increase or decrease moisture build-up and mould and fungal growth. The purpose of this paper is to provide a review of the current global evidence and present the results of in situ monitoring of 15 UK floor voids.

Design/methodology/approach

An extensive literature review on the moisture behaviour in both uninsulated and insulated suspended timber crawl spaces is supplemented with primary data of a monitoring campaign during different periods between 2012 and 2015. Air temperature and relative humidity sensors were placed in different floor void locations. Where possible, crawl spaces were visually inspected.

Findings

Comparison of void conditions to mould growth thresholds highlights that a large number of monitored floor voids might exceed the critical ranges for mould growth, leading to potential occupant health impacts if mould spores transfer into living spaces above. A direct comparison could not be made between insulated and uninsulated floors in the sample due to non-random sampling and because the insulated floors included historically damp floors. The study also highlighted that long-term monitoring over all seasons and high-resolution monitoring and inspection are required; conditions in one location are not representative of conditions in other locations.

Originality/value

This study presents the largest UK sample of monitored floors, evaluated using a review of current evidence and comparison with literature thresholds.

Details

International Journal of Building Pathology and Adaptation, vol. 37 no. 4
Type: Research Article
ISSN: 2398-4708

Keywords

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Article

Bahram Abediniangerabi, Mohsen Shahandashti and Atefe Makhmalbaf

The purpose of this study is to investigate the effect of panel connections on the hygrothermal performance of facade panels using a coupled, transient heat and moisture…

Abstract

Purpose

The purpose of this study is to investigate the effect of panel connections on the hygrothermal performance of facade panels using a coupled, transient heat and moisture transfer analysis.

Design/methodology/approach

A coupled, transient heat and moisture transfer analysis has been conducted to investigate the effect of panel connections in the hygrothermal behavior of facade panels. Governing partial differential equations for the coupled heat and moisture transfer were formulated. Four panel connections proposed by pre-cast/pre-stressed concrete institute were modeled for the ultra-high performance fiber-reinforced concrete facade panel as illustrations and a finite element method was used to solve the numerical models.

Findings

The results of heat transfer analysis showed that steel connections could significantly reduce the thermal resistivity of facade panels by converging heat fluxes and acting as thermal bridges within facade panels. The results also showed that the maximum heat flux in the steel connector of the panel to foundation connection was 10 times higher compared to the other connections. Also, the results of moisture transfer showed that air gaps between the panels had higher moisture flux compared to the other layers in the models. The results show the significant importance of panel connections in the energy performance analysis of facade systems. They also highlight the importance of devising novel connection designs and materials that consider the transient, coupled heat and moisture transfer in the connections to effectively exploit the potential opportunities provided by innovative facade systems to improve building energy efficiency.

Originality/value

This paper, for the first time, investigates the effect of panel connections in the hygrothermal performance of building facade systems using a coupled, transient heat and moisture transfer analysis.

Details

Journal of Engineering, Design and Technology , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1726-0531

Keywords

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