Methods to determine whole building hygrothermal performance of hemp–lime buildings

Barclay, Michael; Holcroft, Neal; Shea, Andrew

doi:10.1016/j.buildenv.2014.06.003

Cited by 49 publications

(21 citation statements)

References 13 publications

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“…Their apparent density was in the range of 356 to 476 kg/m 3 and 405 to 467 kg/m 3 depending on composition, which corresponds to literature data. Similar composites manufactured and examined by other authors were characterized by apparent densities ranging between 258 and 463 kg/m 3 [ 43 ] and between 275 and 440 kg/m 3 [ 44 ]. The apparent density of other plant origin composites, such as straw-clay composite, ranged 241–531 kg/m 3 [ 45 ].…”

Section: Discussionmentioning

confidence: 99%

Composite Materials Based on Hemp and Flax for Low-Energy Buildings

et al. 2017

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The article presents the results obtained in the course of a study on prospective application of flax/hemp wastes as a filling material of lime-based composites in the construction of low-energy buildings. The utilized filler comprised the hydrated lime with clay and Portland cement used as additives. The analysis involved evaluation of such properties as porosity, density, thermal conductivity, absorptivity, permeability, as well as compressive and flexural strength. Depending on the quantity of the filler, the properties of the composite changed. This, in turn, enabled to evaluate whether the utilized composite met the thermal requirements established for low-energy buildings. Afterwards, the obtained data were cross-referenced with the results gathered in the case of a room built of autoclaved aerated concrete. In order to prevent reaching the critical surface humidity, the internal surface temperature had to be calculated. Moreover, the chances of interstitial condensation occurring in the wall made of the analyzed lime–flax–hemp composite were determined as well. The study showed that the composite exhibits low strength, low density, low thermal conductivity, and high absorptivity. The external walls made of the lime–flax–hemp composite receive a limited exposure to condensation, but not significant enough to constitute any threat. The requirements established for low-energy buildings can be met by using the analyzed composite.

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Section: Discussionmentioning

confidence: 99%

Composite Materials Based on Hemp and Flax for Low-Energy Buildings

et al. 2017

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“…In another research, Collet [1] presented that the composite fabricated for walls rising using spraying revealed the total porosity of 79% and open porosity below 70% with the densities of 430-460 kg/m 3 . The research presented in [51] has investigated the composites with densities of 256-460 kg/m 3 and porosities of 80-72%, respectively.…”

Section: Apparent Density and Porositymentioning

confidence: 99%

Capillary Uptake Monitoring in Lime-Hemp-Perlite Composite Using the Time Domain Reflectometry Sensing Technique for Moisture Detection in Building Composites

Brzyski

Suchorab

2020

Materials

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The use of waste plants in the production of building materials is consistent with the principles of sustainable development. One of the ideas involves using hemp shives as an aggregate for the production of a composite used as a filling of the timber frame construction of the walls. The most important disadvantage of using the building materials based on organic components is their susceptibility to the water influence. The wall material is exposed to rising groundwater. The research part of the paper presented the preparation method and the investigation of the hemp-perlite-lime composites. Flexural and compressive strength, apparent density, total porosity, thermal conductivity, and mass absorptivity were examined. The main research part pertained to the analysis of capillary uptake occurrence in the composites, being the important phenomenon present in the external walls. The study on this phenomenon was carried out using the technique of indirect moisture evaluation—Time Domain Reflectometry (TDR). The indirect readouts were additionally verified with the traditional evaluation using the gravimetric method based on the PN-EN 1925 standard. The study proved that the tested composites were characterized by low apparent density, thermal conductivity, strength parameters, high total porosity, and mass absorptivity. The partial replacement of hemp shives by expanded perlite had a beneficial effect on the tested properties of composites.

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“…Results shown in Figure 5. 20 times the thermal mass of the room air [192]. The simulation time-step size was 15 minutes.…”

Section: Estimating Energy-savings Potentialmentioning

confidence: 99%

Improving energy efficiency in office buildings through adaptive control of the indoor climate

Gunay¹

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Zone level heating and cooling systems, lighting and blinds in offices have been either controlled by occupants or automated based on fixed setpoints and schedules. Occupants' control of these systems target maintaining a comfortable indoor climate with minimum number of control actions with little intention to save energy. This leads to the suboptimal utilization of daylight and passive solar heat gains. However, when they are automated to mitigate the extravagance in occupant behaviour, operators tend to choose conservative setpoints and schedules that maintain the comfort of the majority and minimize the frequency of complaints with little consideration to save energy again. Although we have been treating the building controllers as our servants maintaining fixed setpoints and schedules, they represent great potential to implement distributed artificial intelligence. To this end, within the scope of this thesis, an adaptive indoor climate control tool was developed. The tool contains novel algorithms that recursively learn from the occupancy patterns, adaptive occupant behaviours, and develop an inverse model of the heat transfer problem in each zone. The algorithms were designed to be embedded inside local building controllers to undertake the learning process in real-time using a small number of low-cost building sensors. The information derived from the occupants and the building's temperature response was used to autonomously choose operating setpoints and schedules-tailored to exploit the nuances amongst subspaces in a building. The algorithms were implemented and tested for over a year in a controls laboratory which was a shared-office space with a standalone controls network. Furthermore, iii they were implemented and tested in private offices for over a year. Energy and daylighting simulations were conducted to analyze alternative scenarios regarding the design of these algorithms. Implementation results indicate that the use of adaptive indoor climate control algorithms developed in this thesis can substantially reduce the space heating, cooling, and lighting loads in office buildings-without adversely affecting the occupant comfort. The simulation results indicate that adaptive control of the indoor climate not only reduces the expected load intensities but also reduces the risk of poor operational decisions leading to discomfort and excessive energy use. iv Hofstadter 's Law: It always takes longer than you expect, even when you take into account Hofstadter 's Law.

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Methods to determine whole building hygrothermal performance of hemp–lime buildings

Cited by 49 publications

References 13 publications

Composite Materials Based on Hemp and Flax for Low-Energy Buildings

Composite Materials Based on Hemp and Flax for Low-Energy Buildings

Capillary Uptake Monitoring in Lime-Hemp-Perlite Composite Using the Time Domain Reflectometry Sensing Technique for Moisture Detection in Building Composites

Improving energy efficiency in office buildings through adaptive control of the indoor climate

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