Thermal, Moisture and Energy Performance of a Hempcrete Test Structure in the Northern Prairie Climate of Manitoba, Canada

The processing of industrial hemp, cannabis sativa, results in three basic constituents seed, fibre, and hurd. Within Manitoba the main focus is with seed and oil products. When considering the entire plant approximately 60-70% is the predominantly cellulose woody core called the hurd. A combination of hemp hurd, a binder and water in various proportions is used in the construction of buildings referred to as hempcrete. Hempcrete is used as an environmental barrier providing resistance to heat transfer and to manage moisture of the building envelope. Engineering and architectural designers practicing in the field of non-conventional material applications have clearly indicated a need for design data. This paper presents a portion of research data collected over the past 18 months from a 23.8 m2 (256 ft2) test building on the campus of the University of Manitoba at the Alternative Village. The design temperatures for this location range from-35°C to +32°C. The structure was built using 300 mm thick pre-fabricated hempcrete panels. In addition to indoor and exterior ambient conditions, the temperature is monitored at 40 locations within the envelope - at the interior, middle and exterior providing a profile through the wall system. Similarly, the relative humidity is monitored within the wall and used in conjunction with a sorption isotherm to estimate the moisture content within the assembly. The building is kept at a constant temperature during the heating season with the energy consumption monitored continuously. This building is one of several on the test site that are all identical in terms of size and configuration. This paper will provide a comparison between the thermal, moisture and energy performance of the hempcrete structure and a conventional wood frame, batt-insulated building that represents the vernacular construction in Manitoba.

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POWER CONSUMPTION COMPARISON OF FIVE BUILDING ENVELOPES IN THE NORTHERN PRAIRIE CLIMATE OF MANITOBA

Journal of Green Building ◽

10.3992/1943-4618-9.4.147 ◽

2014 ◽

Vol 9 (4) ◽

pp. 147-160 ◽

Cited By ~ 1

Author(s):

Kris J. Dick ◽

Hossein Safavian ◽

Grant Rayner

Keyword(s):

Power Consumption ◽

Thermal Gradient ◽

Building Envelope ◽

Expanded Polystyrene ◽

Expanded Polystyrene Foam ◽

Structural Insulated Panels ◽

Time Period ◽

Concrete Form ◽

Wood Frame ◽

The University

The energy efficiency of a building depends on building envelope performance. The results presented in this paper are the first of a long-term building envelope research project at the Alternative Village at the University of Manitoba in Winnipeg, Manitoba, Canada. Five test buildings were constructed using the following systems: two wood frames with fiberglass batt insulation and dense pack cellulose, one polyurethane structural insulated panels (PUR SIP), and two with the Stay in place PVC concrete form building system using 102mm and 204mm of concrete externally insulated with 102mm of expanded polystyrene foam. All of the buildings had a common foundation and roof system with a footprint of 23.8 m2. Blower door tests were conducted to determine air tightness. Each structure was heated with an electrical resistance heater and maintained at a constant internal temperature. The thermal gradient through the wall and power consumption were monitored. The study period discussed in this report represents the main heating season from October 2011 to April 2012 consisting of 209 days. Based on the power consumption, the PUR SIP consumed the least at 2498 kWh, while the 204 mm Stay in place PVC concrete form building used the most at 2898 kWh for the same time period. The thermal gradient through the cross section of the wood frame structures was compared through the cavity insulation and at the stud. It was found that the cellulose building provided better thermal resistance along the stud when compared to the fiberglass batt insulation.

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Investigation of the envelope’s thermal transmittance influence on the energy efficiency of residential buildings under various Mediterranean region climates

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/899/1/012009 ◽

2021 ◽

Vol 899 (1) ◽

pp. 012009

Author(s):

A C Karanafti ◽

T G Theodosiou

Keyword(s):

Energy Efficiency ◽

Residential Buildings ◽

Residential Building ◽

Energy Performance ◽

Building Envelope ◽

Ambient Conditions ◽

Cooling Period ◽

Thermal Transmittance ◽

System A ◽

Mediterranean Regions

Abstract Improving the energy efficiency of residential buildings is of outmost importance for reducing their environmental footprint. Recent studies demonstrate that a highly insulated building envelope may burden the building’s performance during the cooling period, especially in regions with hot summers. In this study, the energy performance of a residential building in different Mediterranean regions (Jordan, Greece, Iraq, Egypt, Syria, Morocco, Cyprus, Saudi Arabia, Libya, and Spain) is investigated. Two thermal transmittance values are applied to the building shell, a scenario with a very low one and a scenario with a higher one, to examine under which conditions the cooling performance is improved. A dynamic insulation configuration is also implemented, and its operation is studied for the cooling period of each city. It is concluded that in Southern European and Northern African regions building envelopes with lower thermal resistances perform better, while in even Southern regions an increased thermal resistance may prevent the heat from entering the building more effectively. With the switching insulation system, a great reduction in the cooling demands was reported, which reached up to 50% in Spain, and it was shown that in the southern regions the configuration’s operation should be customized to the ambient conditions to optimize its performance.

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Impact of roof shading on building energy performance in warm & humid climatic places of India

iCRBE Procedia ◽

10.32438/icrbe.202037 ◽

2020 ◽

pp. 50-64

Author(s):

Kuladeep Kumar Sadevi ◽

Avlokita Agrawal

Keyword(s):

Energy Consumption ◽

Energy Conservation ◽

Energy Performance ◽

General Assumption ◽

Climatic Conditions ◽

Building Envelope ◽

Passive Cooling ◽

Base Case ◽

U Value ◽

The Impact

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.

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Energy Performance of a High-Rise Residential Building Using Fibre-Reinforced Structural Lightweight Aggregate Concrete

Applied Sciences ◽

10.3390/app10134489 ◽

2020 ◽

Vol 10 (13) ◽

pp. 4489

Author(s):

Zakaria Che Muda ◽

Payam Shafigh ◽

Norhayati Binti Mahyuddin ◽

Samad M.E. Sepasgozar ◽

Salmia Beddu ◽

...

Keyword(s):

Residential Building ◽

Green Building ◽

Lightweight Aggregate ◽

Energy Performance ◽

Building Envelope ◽

Lightweight Aggregate Concrete ◽

Aggregate Concrete ◽

High Rise ◽

Passive Design ◽

Envelope Material

The increasing need for eco-friendly green building and creative passive design technology in response to climatic change and global warming issues will continue. However, the need to preserve and sustain the natural environment is also crucial. A building envelope plays a pivotal role in areas where the greatest heat and energy loss often occur. Investment for the passive design aspect of building envelopes is essential to address CO 2 emission. This research aims to explore the suitability of using integral-monolithic structural insulation fibre-reinforced lightweight aggregate concrete (LWAC) without additional insulation as a building envelope material in a high-rise residential building in the different climatic zones of the world. Polypropylene and steel fibres in different dosages were used in a structural grade expanded clay lightweight aggregate concrete. Physical and thermal properties of fibre reinforced structural LWAC, normal weight concrete (NWC) and bricks were measured in the lab. The Autodesk@Revit-GBS simulation program was implemented to simulate the energy consumption of a 29-storey residential building with shear wall structural system using the proposed fibre-reinforced LWAC materials. Results showed that energy savings between 3.2% and 14.8% were incurred in buildings using the fibre-reinforced LWAC across various climatic regions as compared with traditional NWC and sand-cement brick and clay brick walls. In conclusion, fibre-reinforced LWAC in hot-humid tropical and temperate Mediterranean climates meet the certified Green Building Index (GBI) requirements of less than 150 kW∙h∙m−2. However, in extreme climatic conditions of sub-arctic and hot semi-arid desert climates, a thicker wall or additional insulation is required to meet the certified green building requirements. Hence, the energy-saving measure is influenced largely by the use of fibre-reinforced LWAC as a building envelope material rather than because of building orientation.

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Indoor Airflow Distribution in Repository Design: Experimental and Numerical Microclimate Analysis of an Archive

Buildings ◽

10.3390/buildings11040152 ◽

2021 ◽

Vol 11 (4) ◽

pp. 152

Author(s):

Karin Kompatscher ◽

Rick P. Kramer ◽

Bart Ankersmit ◽

Henk L. Schellen

Keyword(s):

Vertical Gradient ◽

Building Envelope ◽

Cfd Modeling ◽

Indoor Climate ◽

Ambient Conditions ◽

Climate Control ◽

Climate Conditions ◽

Airflow Distribution ◽

Air Mixing ◽

Delay Variations

The majority of cultural heritage is stored in archives, libraries and museum storage spaces. To reduce degradation risks, many archives adopt the use of archival boxes, among other means, to provide the necessary climate control and comply with strict legislation requirements regarding temperature and relative air humidity. A strict ambient indoor climate is assumed to provide adequate environmental conditions near objects. Guidelines and legislation provide requirements for ambient indoor climate parameters, but often do not consider other factors that influence the near-object environment, such as the use of archival boxes, airflow distribution and archival rack placement. This study aimed to provide more insight into the relation between the ambient indoor conditions in repositories and the hygrothermal conditions surrounding the collection. Comprehensive measurements were performed in a case study archive to collect ambient, local and near-object conditions. Both measurements and computational fluid dynamics (CFD) modeling were used to research temperature/relative humidity gradients and airflow distribution with a changing rack orientation, climate control strategy and supply as well as exhaust set-up in a repository. The following conclusions are presented: (i) supplying air from one air handling unit to multiple repositories on different floors leads to small temperature differences between them. Differences in ambient and local climates are noticed; (ii) archival boxes mute and delay variations in ambient conditions as expected—however, thermal radiation from the building envelope may have a large influence on the climate conditions in a box; (iii) adopting night reduction for energy conservation results in an increased influence of the external climate, with adequate insulation, this effect should be mitigated; and (iv) the specific locations of the supply air and extraction of air resulted in a vertical gradient of temperature and insufficient mixing of air, and adequate ventilation strategies should enhance sufficient air mixing in combination with the insulation of external walls, and gradient forming should be reduced.

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Occupant behaviour and thermal comfort in buildings: Monitoring the end user

E3S Web of Conferences ◽

10.1051/e3sconf/201911104056 ◽

2019 ◽

Vol 111 ◽

pp. 04056

Author(s):

Loes Visser ◽

Boris Kingma ◽

Eric Willems ◽

Wendy Broers ◽

Marcel Loomans ◽

...

Keyword(s):

Thermal Comfort ◽

Energy Performance ◽

The Body ◽

Activity Level ◽

Biophysical Model ◽

Zone Model ◽

Occupant Behaviour ◽

Ambient Conditions ◽

Skin Temperatures ◽

Thermoregulatory Behaviour

Studies indicate that the energy performance gap between real and calculated energy use can be explained for 80% by occupant behaviour. This human factor may be composed of routine and thermoregulatory behaviour. When occupants do not feel comfortable due to high or low operative temperatures and resulting high or low skin temperatures, they are likely to exhibit thermoregulatory behaviour. The aim of this study is to monitor and understand this thermoregulatory behaviour of the occupant. This is a detailed study of two females living in a rowhouse in the city of Heerlen (Netherlands). During a monitoring period of three weeks over a time span of three months the following parameters were monitored: activity level, clothing, micro climate, skin temperatures and thermal comfort and sensation. Their micro climate was measured at five positions on the body to assess exposed near body conditions and skin temperature. Every two hours they filled in a questionnaire regarding their thermal comfort and sensation level (7-point scale), clothing, activities and thermoregulatory behaviour. The most comfortable (optimal) temperature was calculated for each person by adopting a biophysical model, a thermoneutral zone model. This study shows unique indivual comfort patterns in relation to ambient conditions. An example is given how this information can be used to calculate the buildings energy comsumption.

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The determination of the thermal reliability criterion for building envelope structures

Tehnički glasnik ◽

10.31803/tg-20181123111226 ◽

2019 ◽

Vol 13 (2) ◽

pp. 129-133

Author(s):

Gennadiy Farenyuk

Keyword(s):

Thermal Insulation ◽

Building Energy ◽

Energy Performance ◽

Building Envelope ◽

Time Analysis ◽

Thermal Reliability ◽

Thermal Failure ◽

Reliability Criterion ◽

Building Operation

The paper presents the basic methodical principles for the time analysis of the variations of envelope structures’ thermal insulation properties and for the substantiation of the thermal reliability criterion, which should allow the analysis of the actual parameters of heat losses during the operation of buildings. In the paper, the state of the envelope structures thermal failure, the concept of building thermal envelope thermal reliability and the principles of its rating are defined. The physical meaning and basic criterion of the envelope structure thermal reliability are formulated. The application of the thermal reliability criterion allows determining the probable variations in the thermal insulation properties during the building operation and, accordingly, the changes of the building energy performance over time.

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Fidelity enhancement of a rotorcraft simulation model through system identification

The Aeronautical Journal ◽

10.1017/s0001924000006102 ◽

2011 ◽

Vol 115 (1170) ◽

pp. 453-470 ◽

Cited By ~ 1

Author(s):

L. Lu ◽

G. D. Padfield ◽

M. White ◽

P. Perfect

Keyword(s):

System Identification ◽

Simulation Model ◽

Linear Models ◽

Aircraft Design ◽

Design Data ◽

Loads Analysis ◽

Physics Based Simulation ◽

Six Degree Of Freedom ◽

The University ◽

Frequency Domain Approach

AbstractHigh fidelity modelling and simulation are prerequisites for ensuring confidence in decision making during aircraft design and development, including performance and handling qualities, control law developments, aircraft dynamic loads analysis, and the creation of a realistic simulation environment. The techniques of system identification provide a systematic framework for ‘enhancing’ a physics–based simulation model derived from first principles and aircraft design data. In this paper we adopt a frequency domain approach for model enhancement and fidelity improvement of a baseline FLIGHTLAB Bell 412 helicopter model developed at the University of Liverpool. Predictability tests are based on responses to multi–step control inputs. The techniques have been used to generate one, three, and six degree-of-freedom linear models, and their derivatives and predictability are compared to evaluate and augment the fidelity of the FLIGHTLAB model. The enhancement process thus involves augmenting the simulation model based on the identified parameters. The results are reported within the context of the rotorcraft simulation fidelity project, Lifting Standards, involving collaboration with the Flight Research Laboratory (NRC, Ottawa), supported with flight testing on the ASRA research helicopter.

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