Mineral Fiber Insulation Research Articles

Shrinkage characteristics of glass and mineral fibre insulation materials at elevated temperatures

The fire resistance of building assemblies can be determined through testing or by numerical modelling. As testing of building assemblies is expensive and time-consuming, the development of numerical modelling methods is gaining momentum. One of the challenges in modelling assemblies’ thermal performance is insulation dimensional shrinkage at elevated temperatures. To address this challenge, this paper presents a comprehensive experimental investigation into the shrinkage of glass and mineral fibre insulation materials under elevated temperature conditions. Initially, a series of tests was conducted to establish the temperature range within which significant shrinkage occurs for both types of insulation. Then, visual observations and measurements were recorded to assess the physical and dimensional changes of the insulation materials within the identified temperature range for shrinkage, indicating distinct responses of glass and mineral fibre insulation to thermal exposure. Compared to width and length variations, thickness reduction in insulation was more significant. Overall, the insulation thickness decreased as the exposed temperature increased. The glass fibre insulation completely melted at 710°C, while mineral fibre insulation disintegrated at 1000°C. In addition, empirical equations were derived to assess the thickness variations of these insulations at elevated temperatures, which can greatly enhance the accuracy of future thermal models under fire scenarios. Lastly, potential areas for future research are identified.

Measured Impact of Material Settlement in a Timber-Frame Wall with Loose Fill Insulation

Loose-fill thermal insulations in timber-frame structures are designed to provide efficient thermal protection with the ability to fill intricate details. In a previous study, we detected several air cavities formed in timber-framed wall samples filled with loose-fill mineral fiber insulation. This discovery led us to retrofit the walls by adding appropriate insulation, thus enabling us to evaluate the importance of proper amendment. This paper focuses on a wall fragment with an 80 mm high air gap at the top and a 30 mm high cavity in the middle of the wall height. The following paper compares data collected before the discovery and after the replenishment (refill of air gaps with additional insulation), evaluating potential thermal performance improvement. We were able to quantify the impact of these defects on the external wall exposed to realistic conditions. Based on temperature and relative humidity measurements, the results show significant advancement in the middle of wall thickness with an 8 °C and 45% difference. The results show that although this defect did not directly affect the energy balance of the building, it significantly increases the risk of mold growth due to thermal bridging.

Moisture performance of a new thermal insulation composite for interior application

The paper introduces prototypes of a new composite insulation product for interior application. The product consists of a standard mineral fibre insulation batt, which is wrapped in a combination of a thin fabric of moisture absorbing, capillary active material and vapour retarding membranes. The insulation composite has been tested with small samples in a laboratory setup and in an outdoor field test on a full-scale brick wall, and has so far shown promising results in comparison with other products. The paper describes the new insulation composite and the initial moisture tests that have been made with its constituents as well as results from the laboratory and field tests of its ability to prevent moisture accumulation.

Influence of envelope insulation materials on building energy consumption

In this paper, the influence of different external wall insulation materials on the energy consumption of a newly built apartment in Germany is investigated. Three types of insulation materials commonly used in Germany including mineral fiber, polyurethane, and vacuum insulation panel are chosen for the case studies. An energy analysis model is established to clarify the primary energy use for production of the insulation materials and for building space heating. The calculation results show that the energy consumption for insulation material production increases with the insulation thickness, whereas the energy use for space heating decreases with the insulation thickness. Thus, there exists an optimum thickness to get the lowest total energy consumption for each kind of insulation material. The ascending order of the total energy consumption of the three materials is mineral fiber, polyurethane, and vacuum insulation panel. However, the optimum insulation thicknesses for the three insulation materials show a verse order at a certain heat transfer coefficient of the base envelope. The energy payback time (EPT) is proposed to calculate the payback time of the primary energy use for insulation material production. Mineral fiber has the shortest time, followed by polyurethane and vacuum insulation panel. The EPTS is 10, 19 and 21 years, respectively when the heat transfer coefficient of the base envelope is 0.2 W/(m2·K). In addition, the simulated results show that the theoretical value and the simulated value are basically identical.

Silent Room: A (non)sensory interactive art installation

Simon Heijdens, a London-based Dutch artist, was commissioned by South by Southwest (SXSW), an annual film, media, and music festival in Austin, TX, to create an installation artwork to premiere at SXSW in March 2016. In reaction to the sensory overload of the festival, he created Silent Room. Students and professors from the University of Texas at Austin worked alongside Mr. Heijdens to design a portable, self-sufficient, reusable space providing sound isolation and absorption from outside and inside the chamber, respectively. Housing the space in a shipping container, Silent Room was successfully built and showcased at SXSW in downtown Austin to hundreds of visitors, achieving a minimum sound reduction of 27 dBA at 40 Hz and a maximum reduction of 55 dBA at 1.45 kHz. These results were achieved using a suspended floor and decoupled wall/ceiling construction of Auralex rubber U-Boats, 2” x 4” wood studs, mineral fiber insulation, plywood, Auralex SheetBlok vinyl, and acoustically treated gypsum board. After initial acoustical measurements, more U-Boats were added, decoupling the container underside from the street and isolating it from ground-borne vibration. However, the room performance worsened after this change, possibly due to exposure to a new air-borne path for noise ingress.

Innovative mineral fiber insulation panels for buildings: Thermal and acoustic characterization

Thermal insulation of building envelope plays a key-role in energy saving: a growing interest is focused on new materials, such as the recycled and sustainable ones. Innovative mineral fiber insulating panels were developed and investigated as a strategy for building refurbishment. The thermal and acoustic properties were investigated in order to compare them to conventional solutions. The thermal conductivity was evaluated by means of a Heat Flow meter apparatus: it is in the 0.031−0.034W/(mK) range, depending on the density. The acoustic absorption coefficient and the Transmission Loss values measured by means of Kundt’s Tube showed a very good acoustic behavior, when compared to conventional solutions with similar chemical composition, but worse mechanical resistance, such as rock wool panels. The low value of thermal conductivity (0.0312W/(mK) for a density of 165kg/m3), together with other characteristics such as acoustic insulation improvement, sustainability (very low presence of additives, such as resin), mechanical resistance, high resistance to fire, and finally easy application in buildings with very low thicknesses (9−27mm) suggest this solution as a very useful one for building refurbishment, especially for historical buildings.

Hybrid and Reflective Insulation Assemblies for Buildings

Materials with a low thermal emittance surface have been used for many years to create reflective insulations that reduce the rate of heat flow across building envelopes. Reflective insulation technology is now being combined with other energy conserving technologies to optimize overall thermal performance. The basis for the performance of reflective insulations and radiant barriers will be discussed along with the combination of these materials with cellular plastic or mineral fiber insulations to form hybrid insulation assemblies. Calculations of thermal resistance for enclosed reflective air spaces and current field data from Southeast Asia will be presented. These data show that reductions in heat transfer across the building enclosure can be effectively reduced by the use of enclosed reflective air spaces and attic radiant barriers. Reflective technology increases the overall thermal resistance of the building enclosure when used to insulate poured concrete structures.

Impact of building materials on indoor formaldehyde levels: Effect of ceiling tiles, mineral fiber insulation and gypsum board

Materials like building products or furnishing present in climatically controlled or uncontrolled indoor environments influence the indoor air quality (IAQ) significantly. In this study, the contribution of formaldehyde emissions from building materials and influences of adsorption/desorption behavior to indoor air pollution is investigated in a custom-made test house environment, located in a climate-controlled 48 m3 stainless steel chamber. The complete test house study comprised three experimental cycles applying different types of ceiling tiles as target building materials. In each cycle one type of ceiling tile was used, while the housing construction and fittings were left unchanged. One cycle was divided into three steps to differentiate the contribution of each material to the overall IAQ: after the background monitoring of the empty housing frame (Step I), ceiling tiles were installed in the house and the air quality was monitored for one week (Step II). Finally, furniture and carpet were introduced into the house and the air was again monitored for one week (Step III). Additionally, gypsum boards and ceiling tiles were characterized by determination of their emission, diffusion and adsorption/desorption rates with regard to formaldehyde. It is the most important finding of this study that the resulting formaldehyde concentration does not simply result from additive emissions from the materials involved. In fact, it can only be explained accurately when taking into account multiple parameters.

Airtightness of the window–wall interface in cavity brick walls

In recent decades there has been an increased focus on enhanced thermal resistance of building components and as a consequence, the relative importance of airtightness on the overall energy losses of buildings has increased significantly. The construction industry requires practical information on the airtightness of individual construction elements and building envelope interfaces. A literature review on the airtightness of window–wall interfaces has shown that no experimental data are available for masonry construction. This paper offers an investigative study on the airtightness of window–wall interfaces of masonry walls, for 13 different installation methods. The results show that the selected solutions cover a wide range of airtightness levels, from 0 m 3/h m up to 31 m 3/h m at 50 Pa. The experiments have permitted determining that a very good performance can be obtained by using polyurethane foam and caulking, airtight membranes, polyurethane foam and plywood framing, and plaster and caulking. On the contrary, mineral fibre insulation, a partial fill with polyurethane foam and plaster without caulking should be avoided when good airtightness is required. Furthermore, a comprehensive methodology for error calculation is offered, based on error propagation of partially correlated parameters, including the effect of measurement errors, extraneous air leakage and conversion to standard boundary conditions.

Integrated Strip Foundation Systems for Small Residential Buildings~!2009-10-20~!2010-01-01~!2010-03-30~!

A prefabricated lightweight element was designed for a strip foundation that was used on site as the bases of two small residential buildings, in this case single-family houses; one was built with a double-brick exterior wall separated by mineral fiber insulation and the other was built with a wood-stud exterior wall with mineral fiber insulation. The element was placed on a stable surface underneath the top soil layer, just 0.25 m below the finished ground surface. The prefabricated element was designed to comply with the requirements of a high energy-efficient performance stipulated in the new Danish Building Regulations. The base of the two individual buildings was cast in one working operation and completed within two working days. Produced and shaped as one coherent element of expanded polystyrene, the element was designed to be handled on site by one man. Non-freezing ground was established by using outer insulation located at the outer plinth. Temperatures were measured at measurement points at the outer plinth and onwards from these points beneath the building. In addition the soil temperature, the temperature within the concrete floor slab and outdoor as well as indoor temperatures were measured.

Evidence for heat losses via party wall cavities in masonry construction

This paper presents empirical evidence and analysis that supports the existence of a significant heat loss mechanism resulting from air movement through cavities in party walls in masonry construction. A range of heat loss experiments were undertaken as part of the Stamford Brook housing field trial in Altrincham in the United Kingdom. Co-heating tests showed a large discrepancy between the predicted and measured whole house heat loss coefficients. Analysis of the co-heating results, along with internal temperature data, thermal imaging and a theoretical analysis indicated that the most likely explanation for the discrepancy was bypassing of the thermal insulation via the uninsulated party wall cavities. The data show that such a bypass mechanism is potentially the largest single contributor to heat loss in terraced dwellings built to the 2006 revision of the Building Regulations. A comparable convective heat bypass associated with masonry party walls was identified in the late 1970s during the course of the Twin Rivers Project in the United States, albeit in a somewhat different construction from that used at Stamford Brook. A similar effect was also reported in the United Kingdom in the mid 1990s. However, it appears that no action was taken at that time either to confirm the results, to develop any technical solutions, or to amend standards for calculating heat losses from buildings. Current conventions for heat loss calculations in the United Kingdom do not take account of heat losses associated with party walls and it is suggested by the authors that such conventions may need to be updated to take account of the effect described in this paper. In the final part of the paper, the authors propose straightforward solutions to prevent bypassing of roof insulation via party walls by for example filling the cavity of the party wall with mineral fibre insulation, or by inserting a cavity closer across the cavity in the plane of the roof insulation. Practical application: The heat bypass mechanism described in this paper is believed by the authors to contribute to a significant proportion of heat loss from buildings in the UK constructed with clear cavities such as those found in separating walls between cavity masonry dwellings. It is proposed that relatively simple design changes could be undertaken to eliminate such heat loss pathways from new buildings. In addition, simple and cost effective measures are envisaged that could be used to minimise or eliminate the bypass from existing buildings. Such an approach could give rise to a significant reduction in carbon emissions from UK housing. a The Department for Communities and Local Government, previously the Office of the Deputy Prime Minister, ODPM. References produced before the change of name are listed under ODPM. b Difficulties in the recruitment of households have delayed the long term monitoring programme to 2007 but, fortuitously, this has provided the capacity for a more detailed investigation of the party wall heat loss issues discussed in this paper with further co-heating tests (incorporating a more detailed measurements) planned for the winter of 2006/07. c A co-heating test involves electrically heating the inside of a house to a constant temperature over a period of several weeks. Correlation of the measured electrical heat input with external temperature and solar insolation then allows an estimation of the total dwelling heat loss coefficient. d House A is an end-of-terrace house with one adjacent house. House E is a mid-terrace house with two adjacent houses, D and F. e In the UK, the regulations consist of a broadly framed, performance based, legal requirement supported by detailed technical guidance on compliance. Such guidance is provided by a system of approved documents issued by the Secretary of State. The current methodology for dwelling heat loss calculations is contained in the Standard Assessment Procedure 200512 which is invoked by regulation 17A and Approved Document L1A.2 f The Building Regulations do limit the leakage of air from within each dwelling into the cavity through an overall limit on dwelling permeability. g The higher-than-normal inside-outside temperature difference during the co-heating tests implies that background ventilation rates and ventilation heat loss coefficients during these tests are likely to have exceeded those in the table. Calculations based on a semi-analytical model of air flow14 suggest that the increase is of the order of 3 WK—1 (10%) for the two-storey house A and 15 WK—1 (27%) for the three-storey house E. h Note that the correction is only used to improve the graphical presentation of the data. The heat loss coefficient is calculated directly from multiple regression of heating power against ΔT and S.

Mineral fiber problems and their management: UK 1890-1935.

The first intimation that mineral fibers other than asbestos were biologically active, is generally identified with reports of experimental studies by Stanton and Wrench, and Pott and Friedrichs, in the early 1970s. In 1890 however, man-made mineral fiber was recognized to present human health hazards; in 1912 experimental study confirmed asbestos to be fibrogenic, and by 1935 other mineral fibers came to notice as potential lung hazards. Published and archival sources have been reviewed to trace the emergence between 1890 and 1935 of the awareness of the health hazards of various fibrous minerals, and the development of strategies for their control. By the early 1900s there was evidence that the asbestos substituted for the man-made mineral fiber insulation material employed to improve the thermal efficiency of steam powered engines, presented a serious health problem. In the early 1930s, other mineral fibers came to be suspected of causing pneumoconiosis. Containment, local exhaust ventilation and personal respiratory protection were instituted for the amelioration of asbestosis, but because of the limitations of what was perceived to be reasonably practicable on economic grounds, and what was feasible technologically, their benefits were severely limited. Initial and periodic medical examination were introduced as precautionary measures, based on hope rather than on experience. When in the early 1930s, the investigation of coal mine dust and siliceous dust, threw up the hypothesis that fibrous natural mineral dusts other than asbestos might be fibrogenic, this was ignored and no further investigations were pursued and no precautionary measures were set in train.

Nasal lavage biomarkers: effects of water damage and microbial growth in an office building.

Selected nasal symptoms were studied in personnel who worked in a damp office building that had microbial growth (including Stachybotrys sp.) in mineral fiber insulation and gypsum board. There were also signs of dampness in the floor. Clinical examinations included nasal lavage and peak expiratory flow measurements in 12 subjects in the damp building; an additional 8 subjects in a control building (i.e., no signs of dampness or microbial growth) were also examined. Hygienic air measurements of microorganisms and volatile organic compounds were performed in both buildings. The concentrations of eosinophil cationic protein, myeloperoxidase, and albumin, and the number of subjects with eosinophils in lavage fluid, were higher among office workers in the damp building than among controls. The damp biiilding had greater amounts of total molds and bacteria in its construction than the building materials in nondamp buildings. In addition, an increase of 2-ethyl-1-hexanol in the indoor air was detected in the damp building-a sign of dampness-related alkaline degradation of diethyl-hexyl phthalate in polyvinyl chloride floor coatings. In conclusion, the results of this study indicate that exposures in a damp office building may cause an inflammatory nasal mucosal response. The results also support conclusions of earlier studies, indicating that building dampness is related to respiratory inflammation.

Industrial Insulation: Protects the Environment, Improves Efficiency, and Saves More Money Than you Can Imagine!

ABSTRACT Stabilizing greenhouse gas emissions to stem the impact of global climate change is becoming one of the hottest topics heading into the new century. Regardless of which side of the issue you are on, there is no debate that increasing energy efficiency is important to environmental preservation. One of the most effective energy efficient technologies available is mineral fiber insulation. The examples presented will give energy management professionals the evidence they need to consider industrial insulation a time-tested, off-the-shelf technology for achieving major reductions in operating costs and C02 emissions.

Analytical Models for Settling of Attic Loose-Fill Thermal Insulation

Settling of attic loose-fill thermal insulation is a long-term process. Settling depends on the quality of the loose-fill insulation and the attic conditions during the service life. The main factors affecting settling of attic loose-fill insulation are density (mass), climate of the attic, and vibrations of the building structure. Analytical models for settling of attic loose-fill thermal insulation can be helpful for both interpretation and prediction of observed settling behaviour. The prediction of the settling process of loose-fill thermal insulation in a model is valuable when estimating the thermal properties of the loose-fill insulation after a certain lifetime. Efforts to carry out a preliminary analytical model for the settling property have been made in two ways. Firstly, experimental field settling data have been used to fit a common logarithmic mathematical function. Secondly, a four-element linear vis coelastic model, the Burger model, has been adjusted to experimental field settling data. Comparison of the thirty years settling data calculated with the fitted logarithmic functions and the Burger equations has been performed for cellulose fibre and mineral fibre insulation (Svennerstedt, 1993).

Novel Innovative Concept for Self-Drying of the Insulation of Cold Piping

The self-drying concept for the insulation of cold piping is based on the wicking action of a hydrophillic fabric which is wound around the pipe and ex tended through the slot of the tubular insulation mantel. If the dew point of the am bient air is below the temperature of the surface of the pipe, water vapour will diffuse through the insulation, condense on the pipe and be sucked up by the wick fabric and transported by wicking action through the slot to the surface of the insulation mantel, from where it will evaporate into the ambient air. In this paper, an experimental set-up is described which within a few hours can demonstrate the self-drying concept. Results are given that show that the concept is able to prevent moisture build up in tubular mineral fibre insulation even without any vapour retarder jacket. The concept can also be used on piping below freezing temperature if the cooling plant is closed down for a short period once a year or every other year, depending on the permeability of the vapour retarder jacket.

Measured Thermal Resistance of Frame Walls with Defects in the Installation of Mineral Fibre Insulation

Studies have shown that convective air flow can significantly reduce the thermal resistance of frame walls insulated with mineral fibre insulation (MFI). It has also been shown that convective air flow can be avoided if the MFI products are installed with at least one face against an air impermeable material. The evolution of MFI products has seen the introduction of products with smaller fibre diameters and lighter densities, and there is a dominance of the frame wall insulation market by fric tion fit products. The effect of these changes on the installed (field) performance of MFI products is unknown, as is the effect of "minor" installation defects on the per formance of frame wall insulation systems. This article examines, through a program of full scale laboratory measurements, the effect of corner installation defects and product density on the thermal resistance of frame walls insulated with MFI prod ucts.

The Thermal Resistance of Spray-Applied Fiber Insulations

The thermal resistances of four cellulosic and three mineral fiber spray-applied m- sulations have been determined using the flat Nichrome screen-heater apparatus de veloped at the Oak Ridge National Laboratory. Measurements were also made at Dynatech Scientific, Inc., on two of the same specimens of the cellulosic material and one similar specimen of the same mineral fiber product using conventional guarded hot plate and heat flow meter apparatuses. The experimental data obtained at ORNL were used to calculate R-values at 75°F from data obtained in the range 81 to 133 ° F The R-values obtained at Dynatech in cluded measurements at 75°F as well as measurements from 50 to 100°F for cellu losic insulations and 25 to 150°F for a mineral fiber insulation. The results from the two laboratories for the thermal resistance of identical specimens of spray-applied cellulose agreed to better than 1% while the agreement on similar specimens of a spray-applied mineral fiber insulation differed by less than 3%. The data discussed in this paper include spray-applied insulations that span the density range 1 to 8 lb/ft3 and the results show that material R -values for the spray- applied products can be predicted to within ± 10%, using correlations for the ap parent thermal conductivities of loose-fill insulation of the same type and density. They show further that existing plate and similar longitudinal heat flow methods are most appropriate for evaluating the performance of these types of materials.

Apparent Thermal Conductivity Measurements by an Unguarded Technique

An unguarded longitudinal heat flow apparatus for measuring the apparent thermal conductivity (λ a) of insulations was tested with mean specimen temper atures from 300 to 330°K on samples up to 0.91 m wide, 1.52 m long, and 0.15 m thick. Heat flow is provided by a horizontal electrically heated Nichrome screen that is sandwiched between test samples that are bounded by tempera ture controlled copper plates and 9 cm of mineral fiber insulation. A deter minate error analysis shows λ a measurement uncertainty to be less than ±1.7% for insulating materials as thin as 3 cm. Three-dimensional thermal modeling indicates negligible error in λ a due to edge loss for insulations up to 7.62 cm thick when the temperature difference across the sample is measured at the screen center. System repeatability and reproducibility were determined to be ±0.2%. Differences of λ a results from the screen tester and results from the National Bureau of Standards were 0.1% for a 10-kg/m3 Calibration Transfer Standard and 0.9% for 127-kg/m3 fibrous glass board (SRM 1450b). Measurements on fiber glass and rock wool batt insulations showed the dependence of λ a on density, temperature, temperature difference, plate emittance, and heat flow direction. Results obtained for λ a as a function of density at 24°C differed by less than 2% from values obtained with a guarded hot plate. These results demonstrate that this simple technique has the accuracy and sensitivity needed for useful λ a measurements on thermal insulating materials.

Thermal performance of mineral fibre insulation

Experimental ‘U’-values have been derived for actual and simulated building components insulated with fibrous material. They cover a range of thicknesses from 90 to 360 mm and the values compare well with theoretical values calculated using CIBS methods. This rebutts earlier reports which suggested that thick layers of insulation perform less well than theoretically predicted.