scholarly journals Internal insulation of solid masonry walls – field experiment with Phenolic foam and lime-cork based insulating plaster

2020 ◽  
Vol 172 ◽  
pp. 01003 ◽  
Author(s):  
Nickolaj Feldt Jensen ◽  
Carsten Rode ◽  
Birgitte Andersen ◽  
Søren Peter Bjarløv ◽  
Eva B. Møller
Keyword(s):  
Relative Humidity ◽  
Cell Structure ◽  
High Relative Humidity ◽  
Masonry Walls ◽  
Mould Growth ◽  
Indoor Climate ◽  
Phenolic Foam ◽  
Closed Cell ◽  
Insulation Systems ◽  
Positive Effect

The study investigated the hygrothermal performance and risk of mould growth in two thermal insulation systems for internal retrofitting purposes; a phenolic foam system with a closed cell structure, and a capillary active diffusion-open lime-cork based insulating plaster. The setup consisted of a 40-feet (12.2 m) insulated reefer container with controlled indoor climate, reconfigured with several holes (1x2 m each) containing solid masonry walls with embedded wooden elements on the interior side and different interior insulation systems, with and without exterior hydrophobisation. Focus was on the conditions in the interface between wall and insulation system, and in the embedded wooden elements. Relative humidity and temperature were measured in several locations in the test walls over two years, and the mould risk was evaluated by measurements and the VTT mould growth model. Findings for the interior phenolic foam system indicated that exposed walls experienced high relative humidity and high risk of moisture-induced problems. Exterior hydrophobisation had a positive effect on the moisture balance for the southwest oriented wall with phenolic foam. The lime-cork based insulating plaster showed high relative humidity and risk of moisture-induced problems, with and without hydrophobisation.

Hygrothermal performance of six insulation systems for internal retrofitting solid masonry walls

2021 ◽  
pp. 174425912098874
Author(s):  
Nickolaj Feldt Jensen ◽  
Søren Peter Bjarløv ◽  
Carsten Rode ◽  
Birgitte Andersen ◽  
Eva B Møller
Keyword(s):  
Relative Humidity ◽  
Open Systems ◽  
Ph Value ◽  
Cell Structure ◽  
Fungal Growth ◽  
Masonry Walls ◽  
Indoor Climate ◽  
North East ◽  
Hygrothermal Performance ◽  
Insulation Systems

The study investigated the hygrothermal performance and risk of fungal growth in a phenolic foam system with a closed cell structure and a diffusion-open and capillary active lime-cork based insulating plaster, for internal retrofitting purposes. The setup comprised two 40-feet (12.2 m) insulated reefer container with controlled indoor climate, reconfigured with 24 holes (1 × 2 m each) containing solid masonry walls with embedded wooden elements on the interior side. Focus was on the conditions in the masonry/insulation interface and embedded wooden elements, and the performance of the two systems were compared to three diffusion-open insulation systems and one diffusion-tight. The effect of exterior hydrophobisation was also investigated. Relative humidity and temperature were measured in several locations in the test walls over 2½ years, and the risk of fungal growth was evaluated by on-site measurements and the VTT mould-growth model. The findings indicate that internally insulated walls with bare brick exterior surfaces performed poorly with high risk of fungal growth. The effect of exterior hydrophobisation was found to vary with the orientation and the installed insulation system, with a generally positive effect on walls facing south-west but limited effect for north-east. Furthermore, the more diffusion-tight insulation systems were found to perform better in combination with exterior hydrophobisation than the highly diffusion-open systems. The lime-cork insulating plaster showed high relative humidity and risk of moisture-induced problems. The on-site fungal tests showed no growth in the masonry/insulation interface inside the two insulation systems, probably due to high initial pH-value.

scholarly journals Hygrothermal assessment of internally insulated historic solid masonry walls with focus on the thermal bridge due to internal partition walls

2021 ◽  
Vol 2069 (1) ◽  
pp. 012079
Author(s):  
N F Jensen ◽  
C Rode ◽  
E B Møller
Keyword(s):  
Relative Humidity ◽  
Numerical Simulations ◽  
Masonry Walls ◽  
Test Field ◽  
Indoor Climate ◽  
Partition Wall ◽  
Interior Surface ◽  
Thermal Bridge ◽  
Hygrothermal Performance ◽  
Insulation Systems

Abstract This study investigated the hygrothermal performance of five insulation systems for internal retrofitting purposes. Focus was on the hygrothermal performance near partition brick walls compared to the middle of the wall. The setup comprised two insulated reefer containers with controlled indoor climate, reconfigured with several holes containing solid masonry walls with interior embedded wooden elements, an internal brick partition wall and different internal insulation systems, with and without exterior hydrophobisation. Relative humidity and temperature were measured over five years in the masonry/insulation interface and near the interior surface, in the centre of the test field and near the partition wall. In addition, calibrated numerical simulations were performed for further investigation of the thermal bridge effect. Findings for the masonry/insulation interface showed higher temperatures and lower relative humidity near the partition wall in comparison with the central part of the wall. Near the interior surface, measurements showed only minor differences between the two locations. The relative effect of the thermal bridge was smaller in the case of a high driving rain load on the exterior surfaces. The numerical simulations showed that the hygrothermal conditions were affected further away from the partition wall than what could be measured in the experimental setup.

A GREENHOUSE EVALUATION OF THE EFFECTS OF SOIL MOISTURE, RELATIVE HUMIDITY, AND HELMINTHOSPORIUM SATIVUM INFECTION ON BRITTLENESS OF BARLEY AWNS

1964 ◽  
Vol 44 (2) ◽  
pp. 157-160
Author(s):  
R. B. MacLaren ◽  
J. D. E. Sterling
Keyword(s):  
Soil Moisture ◽  
Relative Humidity ◽  
Cell Structure ◽  
Ash Content ◽  
High Relative Humidity ◽  
High Soil Moisture ◽  
High Soil ◽  
Greenhouse Evaluation ◽  
Helminthosporium Sativum

High soil moisture and high relative humidity gave a higher incidence of brittle awns on barley than did restricted soil moisture and low relative humidity. Ash content of awns was highest when soil moisture and relative humidity were maintained at high levels. Helminthosporium sativum (P, K and B) infection reduced awn brittleness of one variety and had no effect on the others.No differences in cell structure of the awns were attributed to treatment.

scholarly journals Preparation and Properties of 3-Pentadecyl-phenol In-Situ Modified Foamable Phenolic Resin

2018 ◽  
Author(s):  
Tiejun Ge ◽  
Kaihong Tang ◽  
Yang Yu ◽  
Xiapeng Tan
Keyword(s):  
Molecular Structure ◽  
Phenolic Resin ◽  
Bending Strength ◽  
Cell Structure ◽  
In Situ Modification ◽  
Phenolic Foam ◽  
Closed Cell ◽  
Ft Ir ◽  
Limited Oxygen

In this present study, 3-pentadecyl-phenol was selected as a modifier to prepare a foamable phenolic resin with excellent performance, which was successfully prepared by in-situ modification. Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H NMR, 13C-NMR) were used to test and characterize the molecular structure of the modified resin. The results showed that 3-pentadecyl-phenol successfully modified the molecular structure of phenolic resin with a reduction in resin gel time. The effect of changing the added amount of 3-pentadecyl-phenol on the mechanical properties, microstructure and flame retardancy of the modified foam was investigated. The results showed that when the amount of added 3-pentadecyl-phenol was 15% of the total amount of phenol, this resulted in the best toughness of the modified foam, which could be increased to 300% compared to the bending deflection of the unmodified phenolic foam. The cell structure showed that the modified phenolic foam formed a more regular and dense network structure and the closed cell ratio was high. Furthermore, the compressive strength, bending strength, and limited oxygen index were improved, while the water absorption rate was lowered. However, the foam density could be kept below 40 mg/cm3, which does not affect the load.

A Field Study of Mould Growth for Institute Higher Education Library Buildings in Malaysia

2014 ◽  
Vol 567 ◽  
pp. 553-558
Author(s):  
Ngah Abdul Wahab Suriani ◽  
Nurul Izma Mohammed ◽  
Mohd Faris Khamidi ◽  
Nazhatulzalkis Jamaludin
Keyword(s):  
Higher Education ◽  
Relative Humidity ◽  
Literature Review ◽  
Field Study ◽  
Visual Inspection ◽  
Field Studies ◽  
Mould Growth ◽  
Indoor Climate ◽  
Assessment Technique ◽  
Result Show

This paper is part of a PhD field study that focuses on the importance of conducting a visual inspection and evaluation of the indoor climates in libraries. Libraries contain a large amount of stored books that require a stable relative humidity to guarantee its preservation. Mould can survive and grow when indoor relative humidity is high and fungus is present all the time in the air that we breathe. Recording data through visual inspection and field studies. Its recorded the indoor relative humidity, temperature and lighting to assess mould growth problems. The assessment technique for this paper is based on guidelines survey and literature review. Visual inspection found few symptoms of mould growth that related to the amount of moisture appeared when the relative humidity in the library increases. Finally, the recording data for temperature and relative humidity demonstrate the result show that the stable indoor climate in the library building.

scholarly journals Preparation and Properties of the 3-pentadecyl-phenol In Situ Modified Foamable Phenolic Resin

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1124 ◽  
Author(s):  
Tiejun Ge ◽  
Kaihong Tang ◽  
Yang Yu ◽  
Xiapeng Tan
Keyword(s):  
Molecular Structure ◽  
Phenolic Resin ◽  
Bending Strength ◽  
Cell Structure ◽  
In Situ Modification ◽  
Phenolic Foam ◽  
Closed Cell ◽  
Ft Ir ◽  
Limited Oxygen

In this present study, 3-pentadecyl-phenol was selected as a modifier to prepare a foamable phenolic resin with excellent performance, which was successfully prepared by in situ modification. Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H NMR, 13C NMR) were used to test and characterize the molecular structure of the modified resin. The results showed that 3-pentadecyl-phenol successfully modified the molecular structure of phenolic resin with a reduction in the resin gel time. The effect of changing the added amount of 3-pentadecyl-phenol on the mechanical properties, microstructure, and flame retardancy of the modified foam was investigated. The results showed that when the amount of added 3-pentadecyl-phenol was 15% of the total amount of phenol, this resulted in the best toughness of the modified foam, which could be increased to 300% compared to the bending deflection of the unmodified phenolic foam. The cell structure showed that the modified phenolic foam formed a more regular and dense network structure and the closed cell ratio was high. Furthermore, the compressive strength, bending strength, and limited oxygen index were improved, while the water absorption rate was lowered. However, the foam density could be kept below 40 mg/cm3, which does not affect the load.

scholarly journals Monte Carlo Simulation to Evaluate Mould Growth in Walls: The Effect of Insulation, Orientation, and Finishing Coating

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Ricardo M. S. F. Almeida ◽  
Eva Barreira
Keyword(s):  
Monte Carlo ◽  
Relative Humidity ◽  
Case Studies ◽  
Prediction Models ◽  
Growth Models ◽  
Untreated Wood ◽  
Mould Growth ◽  
Indoor Climate ◽  
Growth Phenomenon ◽  
One Year

Mould growth can have severe consequences both on the health of occupants and on constructions’ durability. Mould growth is a very complex process that depends on many factors such as temperature and relative humidity, presence of nutrients, and exposure time. Several mould prediction models, which allow estimating mould growth in building components and performing risk analysis, are available in the literature, such as the updated VTT model or the Biohygrothermal model. A Portuguese typical wall configuration was used for a sensitivity analysis. The importance of insulation (with and without insulation), orientation (north and south), and finishing coating (gypsum-based rendering, medium density fibreboard (mdf), and untreated wood) for the mould growth phenomenon was tested using both the updated VTT model and the Biohygrothermal model. A total of 12 case studies were investigated. The influence of indoor climate was evaluated by simulating 200 scenarios previously generated using the Monte Carlo method. Each of the scenarios has been applied to the 12 case studies, and 2400 hygrothermal simulations were carried out. Initially, the case studies were simulated using WUFI 1D since both mould growth models require the superficial temperature and relative humidity as input. Simulations were carried out for a one-year period. The updated VTT model produced results (mould index—M) ranging between 0.4 (gypsum-based rendering, insulated, and south oriented wall) and 5.9 (untreated wood, noninsulated, and north oriented wall) and the Biohygrothermal model (mould growth) between 10.1 and 406.4 mm for the same case studies. Despite that the effect of the orientation of the wall could be identified, the importance of insulation and nature of substrate was more evident. Although the two models produced overall comparable results, some differences could be found, creating the opportunity to discuss their strengths and weaknesses as well as their sensitivity to the input parameters.

Persistence of nosocomial bacteria on 2 biocidal fabrics based on silver under conditions of high relative humidity

2014 ◽  
Vol 42 (8) ◽  
pp. 879-884 ◽  
Author(s):  
Rosa López-Gigosos ◽  
Alberto Mariscal ◽  
Mario Gutierrez-Bedmar ◽  
Eloisa Mariscal-Lopez ◽  
Joaquín Fernández-Crehuet
Keyword(s):  
Relative Humidity ◽  
High Relative Humidity

A comparison of hygrothermal simulation results derived from four simulation tools

2021 ◽  
pp. 174425912098876
Author(s):  
Maurice Defo ◽  
Michael Lacasse ◽  
Abdelaziz Laouadi
Keyword(s):  
Relative Humidity ◽  
Outer Layer ◽  
Growth Index ◽  
Mould Growth ◽  
Simulation Tools ◽  
Assembly Design ◽  
Hygrothermal Simulation ◽  
Moisture Performance ◽  
Wood Frame ◽  
Wall Assembly

The objective of this work was to compare the hygrothermal responses and the moisture performance of four wood-frame walls as predicted by four hygrothermal (HAM) simulation tools, namely: DELPHIN, WUFI, hygIRC and COMSOL. The four wall systems differ only in their cladding type; these were fibreboard, vinyl, stucco and brick. Three Canadian cities having different climates were selected for simulations: Ottawa, Ontario; Vancouver, British Columbia and Calgary, Alberta. In each city, simulations were run for 2 years. Temperature and relative humidity of the outer layer of OSB sheathing were compared amongst the four simulation tools. The mould growth index on the outer layer of the OSB sheathing was used to compare the moisture performance predicted by the respective hygrothermal simulation tools. Temperature profiles of the outer layer of the OSB sheathing were all in good agreement for the four HAM tools in the three locations. For relative humidity, the highest discrepancies amongst the four tools were found with stucco cladding where differences as high as 20% could be found from time to time. Mould growth indices predicted by the four HAM tools were similar in some cases but different in other cases. The discrepancies amongst the different HAM tools were likely related to: the material property processing, how the quantity of wind-driven rain absorbed at the cladding surface is computed and some implementation details. Despite these discrepancies, The tools generally yielded consistent results and could be used for comparing the impacts of different designs on the risk of premature deterioration, as well as for evaluating the relative effects of climate change on a given wall assembly design.

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