Straw Bale Research Articles

Natural Material Awareness; Periodic Study

Nowadays a lot of enviromental problems are created by shanty settlements. Structures, raw materials of the structures are the main reasons of these enviromental problems. The reasons for these problems are using natural resources and energy, also creating and throwing waste materials away. Structure’s effect on the enviroment depends on their positive and negative features. Studies about sustainability tell us that an ideal structure's features are being built by natural resources, consuming small energy and receiving that energy from the sun and being easy and economic to care. A construction and the materials that are used in it should contain materials that is suitable and healthy for human life more than toxic and industrial materials. Sustainable materials are: adobe, wood, straw bale, steel, sandstone, plaster, ytong and natural rocks. As a construction material soil started to dissappear when concrete entered the construction market. That’s why we should reconsider soil and combine old methods with the needs of our current life's requirements to rehabilitate and raise consciousness about soil. Soil’s natural structure and the comfort it provides to the construction process and also soils's being recycleable and contribution of sustainability to the environment creates new goals for new researches about modern construction culture. Keywords ; Adobe, Space, Practice. DOI : 10.7176/JSTR/5-2-28

Hygrothermal behaviour of straw bale walls: experimental tests and numerical analyses

Straw is an organic material with hygroscopical properties. The high capacity it has of storing moisture from the surroundings can furthermore influence the performance and lead to the possible degradation of the material thereof. The aim of this study was to assess the conductance C-value of a complex material such as straw. A climatic chamber was used to study a sample, which reproduces a traditional plastered straw bale wall. Tests were conducted under different boundary conditions, setting constant values for temperatures and relative humidity. The revision of the assessment's results allowed the calculation of conductance and conductivity values under different conditions. A numerical model was then designed starting from the laboratory data, which was used to characterize material properties. The match between software simulations and laboratory analyses will be a starting point for further tests. Determining the straw conductance C-value is a difficult task to achieve, due to the complexity and the unique properties of the material. In spite of all this, laboratory tests have shown encouraging results, which reflect the great potential of straw as a building material.

Straw bale based constructions: Measurement of effective thermal transport properties

The use of eco-friendly thermal insulations in the building envelope is one of the passive and also sustainable means of achieving indoor thermal comfort. There are possibilities for significant improvements in energy efficiency over the life of a building with the prospect of reduced use of energy intensive space-conditioning technologies. Straw, an agricultural residue, with potential for utilization as an insulation material, is the focus of the current work. Reliable transient analysis of straw based construction requires knowledge of its thermal transport properties – effective thermal conductivity and thermal diffusivity. Variability in thermal conductivity owing to several factors and lack of thermal diffusivity values are the main takeaways from the comprehensive literature review undertaken and therefore, the current work attempts to address these issues. The measurements of these thermal transport properties of rice straw bale sample are carried out using transient plane source technique. The ranges of the influencing parameters considered are: temperature from 25 °C to 45 °C, packing density from around 50–90 kg m−3 for dry samples as well as samples conditioned at 40%, 60% and 80% RH. The experiments are performed for three different orientations with respect to heat flow: parallel, random and perpendicular. The effective thermal conductivity values obtained in the case of perpendicular/random orientation are approximately 1.7 times lower compared to parallel case. A significantly greater increase, as much as 130% and 60%, in thermal conductivity is found in parallel oriented case than perpendicular/random cases with increase in relative humidity and density, respectively. The thermal diffusivity values also show significant variation only in the parallel case. Correlations are proposed for both thermal conductivity and thermal diffusivity for all orientations.

Does grouping environmental enrichments together affect the way they are used by commercially housed broiler chickens?

Identifying the most attractive ways of presenting environmental enrichments in commercial broiler housing may encourage use and optimise their effectiveness. This study investigated the effect of grouping straw bales (SB), oat hulls (OH; as a dustbathing substrate) and pecking chain (Pe) together, compared to providing individual enrichments, on level of enrichment use and the behaviour of proximate broilers. Approximately 56 000 Ross 308 broiler chickens were placed in two matched commercial houses on one farm (max. 30 kg/m2). On day 4, SB, OH (in steel rings 1.1 diameter, 7.62 cm deep), and black/yellow plastic Pe were introduced. These enrichments were grouped into seven enrichment combinations per house: 1) SB only, 2) OH only, 3) Pe only, 4) SB + OH, 5) SB + Pe, 6) OH + Pe, and 7) SB + OH + Pe. The farm was visited twice weekly over one production cycle in weeks 2, 3, 4 and 5. Behavioural data were collected using scan and focal sampling from video footage. Each enrichment type was compared with its three alternative combinations. In general, level of use of SB and OH was similar to previous research, but use of Pe was higher than anticipated. Enrichment combination did not have a significant effect on the number of broilers around the straw bales or in the oat hull rings, or on the types of behaviours observed. Focal observations of direct enrichment use revealed that significantly more vertical wingshakes were performed when the oat hulls were placed singly (OH) rather than in the SB + OH + Pe combination (P = 0.026). There was a significant interaction between enrichment combination and week for the number of pecks directed at the straw bales (P = 0.013), and no effect of enrichment combination on the number of pecks directed at the pecking chain (P > 0.05). Specific effects of placing SB close to OH (as a possible form of vertical cover) on levels of dustbathing and disturbance was examined, but no significant effects were found. In conclusion, we found no obvious benefits to grouping these enrichments together rather than providing them singly, and some practical benefits to placing enrichments individually (such as more even distribution of fresh straw throughout the house). Straw bales did not appear to offer significant protective cover around dustbathing areas, with no increase in comfort behaviours or reduction in disturbances observed. Broilers were substantially more interested in pecking chain than has been previously reported, highlighting the need for more commercial scale research.

Behaviour of Walls Constructed using Kelempayan (Neolamarckia cadamba) Wood Wool Reinforced Cement Board

This research investigated the behaviour of walls produced from wood wool cement board (WWCB) which were reinforced with a lesser known commercial timber, Kelempayan, when subjected to compression load. Kelempayan timbers were shredded into wood wool and used as reinforcement agent in this study. WWCB having dimensions of 600 × 2400 × 50 mm and 600 × 2400 × 75 mm, respectively, were fabricated. Properties of the WWCB samples, namely swelling, bending and compression strength were tested. 75 mm WWCB has higher fracture toughness but lower strength compared to 50 mm WWCB. Four types of wall systems with different type of configuration were produced and the test results were compared focusing on their value of ultimate load and failure mode. Walls that constructed without application of link and plaster displayed the poorest performance. Plastered and linked wall had the highest ultimate load and comparable with other load bearing walls. The results suggested that walls constructed using WWCB reinforced with Kelempayan wood wool are suitable for load bearing as they exhibited comparable properties when compared to the other load bearing walls such as masonry and straw bale wall.

Study on round rice straw bale wrapping silage technology and facilities

Specific to problems of the existing round bale wrapping machine in China, such as small application scope and failing to satisfy the wrapping demands of round bales of different specifications, a tumbler-type round bale wrapping machine based on wrapping silage with stretch film was designed. By theoretical analysis and preliminary experiments of the corresponding wrapping process, revolving speed of tumbler, speed ratio between tumbler and carrier rollers, and pre-load force of stretch film were determined as experimental factors, while wrapping time and consumption of stretch film per unit mass of round bale were determined as evaluation indexes. Furthermore, quadratic regression orthogonal rotational combination experimental design was adopted to carry out the wrapping experiment. The regression models were set up, and influencing rules of experimental factors on evaluation indexes were also analyzed. The optimal parameter combination scheme was revolving speed of tumbler of 31-32 r/min, speed ratio between tumbler and carrier rollers of 2.6, and pre-load force of stretch film of 20-22 N. Under such a circumstance, the corresponding wrapping time required was 37.7-38.9 s and consumption of stretch film per unit mass of round bale was 3.21-3.46 kg/t. The predicted values and the measured values of evaluation indexes basically coincided with each other and the relative error fell below 5%, which indicated that both the optimized regression models acquired through the wrapping experiment and the relevant parameter optimization results were reliable. To guarantee the quality of rice straw silage, the round bale should be wrapped by no less than five layers of stretch films through the utilization of the tumbler-type round bale wrapping machine. The study results could be used as references for research and development of the round bale wrapping machine. Keywords: round bale, silage, wrapping machine, tumbler-type, analysis, experiment DOI: 10.25165/j.ijabe.20181104.2855 Citation: Li L Q, Wang D F, Yang X. Study on round rice straw bale wrapping silage technology and facilities. Int J Agric & Biol Eng, 2018; 11(4): 88-95.

Design, evaluation and heat transfer analysis of novel forced draft paddy straw bale combustor using heat sink pipe networks for greenhouse heating

In this study, first of its kind novel design of forced draft paddy straw bale combustor (FDPSBC) coupled with innovative pilot fuel injection system (PFIS) and furnace embedded internal water heat-exchanger for large scale water heating is presented. PFIS is optimized to spray 1.5 ml of diesel after every 3 min interval to achieve complete combustion of the compressed bale by maintaining the flame sustainability. Stainless steel heat-exchanger has 62 L water holding capacity circulating at the rate of 36 L per min using the heat of flue gas and has the capacity to heat 1000 L of water from 30 °C to 65 °C within three hours. Heat of combustion (>90% combustion efficiency) was utilized to generate flue gas at 350 °C and hot water above 65 °C applied to 100 m2 area greenhouse heating located at Punjab Agricultural University, Ludhiana (30.56°N), Punjab, India by designing two heat sink pipe networks; flue gas heat sink pipe network (FGHSPN) fabricated with galvanized iron (GI) and hot water heat sink pipe network (HWHSPN) fabricated with mild steel (MS) respectively laid inside the greenhouse for transfer of heat by radiation and free convection modes. Developed mathematical models showed that FGHSPN was able to transfer 9.6 kW (74%) and where as HWHSPN could transfer 3.38 kW (26%) of heat respectively out of the total heat (12.98 kW) transferred by both the networks to maintain the greenhouse air temperature 10 °C higher than the ambient air temperature after sunset hours as validated by experimental trials conducted in the month of November 2017. Installation cost of FDPSBC technology is Rs 5,00,000 ($8000) and with 24 h continuous operation, it can save about 80 kWh per day and can recover the 50% of installation and operating costs within five years time besides managing about 27% of the total paddy straw available in the state of Punjab (India) through useful heating applications including greenhouse heating.

Construction and monitoring of experimental straw bale building in northeast China

Straw bale buildings have the potential reduce the environmental impact of construction. Although the technique has been introduced into northern China more than a decade ago, the construction method and potential problems within straw bale walls have not been fully understood in existing research. Following an analysis of existing straw bale construction both in north China and worldwide, this paper proposes modifications to the straw bale construction details currently used in north China. The modifications involve in-fill raw material, toe-up design and lime render application. These modifications were incorporated into an experimental building constructed in north China, and after having been monitored for 12 months, the modified construction details were critically assessed. The data demonstrate that rice straw bale walls are resistant to agents of decay and offer reduced construction time and cost than standard wall construction in north China. The construction method has the potential to become a mature construction system in the Chinese market in the future offering significant benefits both in construction and operational cost and in environmental impact.

Static and Dynamic Thermal Characterization of Timber Frame/Wheat (Triticum Aestivum) Chaff Thermal Insulation Panel for Sustainable Building Construction

Common wheat is currently the most widely grown cereal and its grains are mainly used to produce white bread. Contrary to plant seeds, the plant itself may be considered an agricultural waste which is used as an animal feed, soil fertilizer, or pelletized solid fuel to produce heat energy. While wheat straw is used widely in sustainable building construction, mostly as straw bales, the use of the thin dry husk around the grain, the wheat chaff, remained unexplored. An insulation panel made of a medium-density fiberboard (MDF) envelope and wooden studs was manufactured. The 150-mm gap between the MDFs was filled with dry wheat chaff. The thermal transmittance of the panel was determined under static and dynamic thermal conditions using a modified guarded hot box method. The results were compared to an insulation panel of the same construction that was filled with mineral wool. The thermal transmittance of wheat chaff under steady-state and dynamic conditions was 0.307 W m−2 K−1 and 0.298 W m−2 K−1, respectively. While in steady-state conditions the mineral wool outperforms the wheat chaff insulation, after a period of dynamic thermal loading, the ability of both insulations to resist heat-energy dissipation becomes similar. In conclusion, wheat chaff agrowaste seems to be a promising environmentally friendly alternative to artificial thermal insulation. Moreover, the determination of the thermal transmittance of bio-based materials with relatively high specific heat capacities under dynamic thermal loading, provides more accurate results, compared to steady-state conditions.

Ecological Wall Systems as an Element of Sustainable Development—Cost Issues

Building construction based on ecological, locally available, and slightly processed materials have a positive effect on the environment and local economy. Due to its simplicity, and thus possibility to erect a building on one’s own and using inexpensive materials, it may potentially become a solution to satisfy the continuously growing demand for residential buildings. In the paper, three variants of ecological external walls were proposed: a wall made of clay blocks insulated with mineral wool boards; a wall made of clay compacted in formwork insulated with mineral wool boards; and a wooden frame structure filled with straw bales and cladded with fiberboards. The layers of the walls were chosen in such a manner that the heat transfer coefficient values for the studied variants are as equal as possible (0.2 W/m2K), thus allowing for a reliable comparative study. The cost calculation of each variant of walls construction was made. The obtained results allow selection of a more advantageous solution.

Time-dependent mechanical properties of straw bales for use in construction

Straw bale construction is a building technique with low environmental impact that has been gaining popularity over the last few decades. The aim of the paper is to contribute to the assessment of the potential of straw bales as a building material by measuring their dynamic mechanical properties and by modelling their response in time to mechanical load. To this end, relaxation tests, creep tests and tests with cyclic loads were performed on small prismatic straw bales at different loading levels. Data were fitted using different models: power models for cyclic load data and stretched exponential models for creep and relaxation data. Results show that bales exhibit a viscous-type response; the models used for data fitting predict that straw bales eventually settle to an asymptotic value of displacement in case of creep and of force in case of relaxation. Under cyclic loading, straw bales can dissipate energy; such capability, as well as the elastic performance of straw bales, decreases as cyclic loading continues, but can be retrieved after some time of resting from loading. A comparison between the creep performance of straw bales and that of conventional building materials showed that, in this respect, straw bales perform on average in a similar manner to masonry brickwork.

Integrated assessment methods applied to the materials of a high-altitude building

The article intends to highlight how building in exceptional environmental conditions (e.g. sites inaccessible to traditional vehicles, particularly harsh climate conditions, etc.) and reducing the environmental impact of the built environment lead to the adjustment of construction techniques, through applications of materials, even traditional, but made more efficient by innovative offsite and onsite production processes. A Life Cycle Assessment study has enabled to compare the impact of rice-based straw bale as a building material having both a load-bearing and insulation function, and to compare the results achieved with alternative scenarios characterised by materials conventionally used in construction, such as rock wool and concrete and masonry.

Straw bale construction in northern China – Analysis of existing practices and recommendations for future development

Straw bale buildings in China have been mainly limited to rural farm houses and self-builders. An expansion of straw-bale construction into main-stream medium-rise buildings has the potential to make a significant contribution to the reduction of both embodied and operational carbon in China as well as removing a major source of pollution. As a response, there has been the construction of straw bale buildings, however these buildings have several issues, resulting in the limited adoption of the technology.This paper makes recommendations for future straw bale design in northern China based on an inspection of existing buildings. The issues identified with existing construction details were subjected to computational simulation analysis which identified shortcomings in existing practice and proposes revisions to design detail in order to accommodate the environmental conditions in northern China. The paper provides a unique insight into current straw bale practice in northern China and proposes a practical and environmentally sound solution to the pollution crisis in this region.

Effects of environmental complexity on fearfulness and learning ability in fast growing broiler chickens

Increasing environmental complexity, i.e. by providing environmental enrichment, has been suggested as a way to improve broiler chicken welfare. One issue affecting broiler welfare is the level of fearfulness of the flock. Exaggerated fear responses may cause smothering and mortality. Environmental complexity has been found to reduce fearfulness in several species. It is known to promote the development of cognitive functions, including learning and memory. The aim of this study was to test the hypothesis that housing environments of different complexity, due to environmental enrichment or manipulation of standard resources, have an effect on learning ability and fearfulness in broilers. Fifty-eight pens with approximately 500 broilers in each (Ross 308), corresponding to a stocking density of 40 kg/m2, were used. Commercial feed and water were provided ad libitum, and wood shavings were used as litter material. Five environmental enrichment treatments (roughage, vertical panels, straw bales, elevated platforms at different heights), three treatments where the standard resources had been manipulated (increased distances between feed and water, lower stocking density) and one control group were randomly assigned to each pen. At 21 d, 10 broilers from each pen with treatments straw bales, elevated platforms, lower stocking density and control group were tested in a passive avoidance-learning task. At 31 d, 30 broilers from each pen from all treatment groups were subjected to a tonic immobility test. There was a tendency for broilers housed with access to straw bales to have better performance in a passive avoidance-learning task compared to broilers in the control group (F3,92 = 2.22; P = 0.091). In addition, chicks housed with access to 30 cm elevated platforms displayed shorter duration of tonic immobility compared to chicks housed with increased distance between feed and water (F8,49 = 2.22; P = 0.041; Tukey’s test P = 0.038), suggesting decreased fearfulness. The results show that increasing environmental complexity can have positive effects on decreasing fearfulness and promoting learning ability in broiler chickens, improving their welfare.

Productive Performance of Ossimi Ewes Post-Lambing as Affected by Selenium Yeast and/or Vitamin E Supplemented Rations Under Two Different Housing Types

This experiment was carried out to study the effect of selenium yeast (SeY) and/or vitamin E (VitE) supplemented diets which is a commercial antioxidants containing SeY and VitE on productive performance and some blood biochemical parameters of Ossimi ewes and their offspring under two different housing types. Eighty Ossimi ewes in late pregnant period were divided into two equal groups (40 ewes each), the first group averaged 40.38±0.93kg body weight and was settled in semi-opened house with concrete floor and roofed with west-east direction (1st H). While the second group averaged 39.49±1.12kg body weight and was settled in fully shaded house, roofed by single asbestos sheetin and topped with rice straw bales and natural earthen ground with north-south direction (2nd H). Each group randomly divided into four equal subgroups; G1: fed 40% rice straw + 60% concentrate feed mixture (control). G2: fed control + 0.3 mg SeY /kg diet. G3: fed control + 40 mg VitE /kg diet. G4 fed control + 0.3 mg SeY and 40 mg VitE /kg diet. Results indicated that ewes body weight was higher (P 0.05) differences for all blood constituents' values among groups in the 1st house. While, concentrations of serum total protein, albumin, globulin, glucose and cholesterol were significantly (P<0.05 and P<0.01) higher in the treated groups (G2, G3 and G4) than those in G1 in 2nd house type. Concerning serum AST and ALT values obtained here in were within the normal range for healthy sheep. It was concluded that dietary supplementation with SeY plus VitE could be used for the improvement in productive performance of pregnant and lactating ewes post-lambing without any side effects on the general health. Also, sustenance in the second house type had useful impacts on improving growth rate, feed conversion rate, milk production and some related serum biochemical indicators.

Construction Time of Three Wall Types Made of Locally Sourced Materials: A Comparative Study

Similarly to any other industry, the construction sector puts emphasis on innovativeness, unconventional thinking, and alternative ideas. At present, when sustainable development, ecology, and awareness of people’s impact on the environment grow in importance, low impact buildings can become an innovative alternative construction technology for the highly industrialized construction sector. The paper presents a comparative study of three walls made of available materials used locally, which can be classified as biosourced materials, in terms of construction time. The comparison of times necessary to make 1 m2 of the wall allows us to decide which building technology is more advantageous in terms of the construction duration. A shorter construction time means lower labour costs and lower expenses for construction machines. In order to obtain answers to the questions posed, the authors made extensive searches of source data on the time‐consuming building works which used locally sourced materials. Reference is made to “Temporary principles of erecting clay buildings” issued by the Institute of Housing Construction in Warsaw (Poland). Three types of walls made of locally sourced materials were studied: a wall made of clay blocks insulated with mineral wool boards, a wall made of clay compacted in formwork, and one insulated with mineral wool boards and wooden frame structure filled with straw bales and cladded with fibreboards. The layers have been chosen in such a manner that heat transfer coefficient values for the studied variants are as equal as possible (0.2 W/m2 K), thus allowing a reliable comparative study.

Study on round rice straw bale wrapping silage technology and facilities

Specific to problems of the existing round bale wrapping machine in China, such as small application scope and failing to satisfy the wrapping demands of round bales of different specifications, a tumbler-type round bale wrapping machine based on wrapping silage with stretch film was designed. By theoretical analysis and preliminary experiments of the corresponding wrapping process, revolving speed of tumbler, speed ratio between tumbler and carrier rollers, and pre-load force of stretch film were determined as experimental factors, while wrapping time and consumption of stretch film per unit mass of round bale were determined as evaluation indexes. Furthermore, quadratic regression orthogonal rotational combination experimental design was adopted to carry out the wrapping experiment. The regression models were set up, and influencing rules of experimental factors on evaluation indexes were also analyzed. The optimal parameter combination scheme was revolving speed of tumbler of 31-32 r/min, speed ratio between tumbler and carrier rollers of 2.6, and pre-load force of stretch film of 20-22 N. Under such a circumstance, the corresponding wrapping time required was 37.7-38.9 s and consumption of stretch film per unit mass of round bale was 3.21-3.46 kg/t. The predicted values and the measured values of evaluation indexes basically coincided with each other and the relative error fell below 5%, which indicated that both the optimized regression models acquired through the wrapping experiment and the relevant parameter optimization results were reliable. To guarantee the quality of rice straw silage, the round bale should be wrapped by no less than five layers of stretch films through the utilization of the tumbler-type round bale wrapping machine. The study results could be used as references for research and development of the round bale wrapping machine. Keywords: round bale, silage, wrapping machine, tumbler-type, analysis, experiment DOI: 10.25165/j.ijabe.20181104.2855 Citation: Li L Q, Wang D F, Yang X. Study on round rice straw bale wrapping silage technology and facilities. Int J Agric & Biol Eng, 2018; 11(4): 88-95.

Hysteresis Analysis of Prestressed Brick Frame with Strawbale Masonry Infill Subjected to Seismic Loads

This study looks at designing and evaluating strength of typha strawbale wall cross section rather than the assumption of edge column acting as axially loaded members that should resist all vertical members from the loads acting on the wall. Based on the aforementioned claim, the objective of this work is to provide the average design thickness for the cement-plastered typha strawbale that stiffens the prestressed brick frame. Data on strength and deformation of the structure are the input for the analytical models. Pseudo-dynamic earthquake response tests, of a one quarter (¼) scale model low rise storeys prestressed brick frames stiffened with cement plastered strawbale masonry was conducted. The structure is idealized as plane frames. The analysis utilised the hysteresis models for members’ models as timeindependent. The force-displacement relationship of the members’ models has been evaluated by the approximate method on the basis of the material properties and structural geometry. A model was investigated with straw bale infill panel to determine the hysteretic parameters, stiffness deterioration and strength degradation due to seismic forces.

A RESEARCH ON THE PERCEPTION OF ARCHITECTURE STUDENTS ABOUT STRAW-BALE BUILDINGS

Although straw-bale construction has been used for thousands of years, currently doesn‟t attract considerable attention by professional architects and students. The reason behind this is assumed to be the prejudices and lack of knowledge about straw-bale buildings. In the scope of this research understanding candidate architects point of view on the preference criterias that are effective about choice of straw-bale construction is aimed. For this purpose, among 214 students of private university (in Turkey) in 2015-2016 academic year, 100 students were selected through simple random sampling and the survey was conducted. The results show that according to the candidate architects, the properties such as its being compatible to nature, harmless to human health, recyclable and low-cost are the main positive qualities of straw-bale construction, whereas lifetime, structural properties and fire resistance are still calling into question. This study demonstrates that straw bale construction techniques, which have the potential to solve environmental problems, need to be given more attention in the architecture educational. Keywords: Straw-bale construction, preference criterias, architecture students

THERMAL PERFORMANCE OF PANELS WITH HIGH DENSITY, RANDOMLY ORIENTED STRAW BALES

This paper describes the hot-box testing (based on ASTM C1363-11) of seven straw bale wall panels to obtain their thermal conductivity values. All panels were constructed with stacked bales and cement-lime plaster skins on each side of the bales. Four panels were made with traditional, 2-string field bales of densities ranging from 89.5 kg/m3–131 kg/m3 and with the bales on-edge (fibres perpendicular to the heat flow). Three panels were made with manufactured high-density bales (291 kg/m3–372 kg/m3). The fibres of the manufactured bales were randomly oriented. The key conclusion of this paper is that within the experimental error, there is no difference in the thermal conductivity value for panels using normal density bales and manufactured high density bales up to a density of 333 kg/m3. However, because of lack of precision of the hot-box, no conclusions can be made on the true thermal conductivity of the high density bale panels. In addition, the panels tested were found to have significant voids between bales, and this is believed to have contributed to higher measured thermal conductivity values compared to those reported in the literature for normal density bale panels. Thermal properties may be affected for bales with higher densities than 333 kg/m3, therefore further testing is suggested.