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Effect of service life in the emission assessment of ventilation systems. A case study in an office building
Full text linkIn the construction sector, the total carbon footprint of a building measures the greenhouse gas (GHG) emissions associated with all the stages in the building’s life cycle, including the replacement of elements over the years. The calculations are very relevant for installation systems, which generally have a shorter lifetime than the building itself and need to be replaced for proper operation of the building. Ventilation systems, particularly, are complex and include diverse components of various materials, functions and service lifetime. The literature data about the service life in years for the components is fragmented, different in diverse guidelines, or not specified for each composing component.
The impact of replacing ventilation system components was studied in a case study in an office building in Bergen, Norway. The emissions from the replacement were assessed for three replacement scenarios during the service life of 60 years. The first scenario was based on the experience of specialists dealing with ventilation systems and data from the literature. Two other border scenarios were considered: one frequent and one rare replacement of components through the years.
From the expert-assumed values, the emissions from the replacement are approximately 1.5 times higher than the emissions from the production of the components. When a frequent substitution occurs over the years, the emissions from the replacement cover approximately 2.5 times the emissions from the production, while when the replacement occurs rarely, the emissions are less than half of the embodied emissions. The assessment showed high fluctuations in the results when different scenarios were applied, highlighting the need for further work in the field to determine and unify the service life of components. A comprehensive database with service lives for installation components, and an increase of EPDs for such products from the producers would facilitate the assessment and integration of the carbon emissions of such systems in the overall carbon footprint of the building.publishedVersio
ZEN KPI tool user guide. A visual guide to using the ZEN KPI tool
Full text linkDette dokumentet er en brukerveiledning for ZEN KPI-verktøyet, utviklet ved forskningssenteret for nullutslippsområder i smarte byer (FME ZEN) i perioden 2017–2024. Verktøyet gir brukerne mulighet til å spore, rapportere, og visualisere ytelsen til et nullutslippsnabolag gjennom både i den strategiske planleggingsfasen og i implementeringsfasen. Verktøyet dekker ulike KPI-er innen seks kategorier: klimagassutslipp, energi, effekt, byform og arealbruk, mobilitet og økonomi. Denne veiledningen inneholder en detaljert, trinnvis forklaring for å bruke ZEN KPI-verktøyet effektivt.This document serves as a user guide for the ZEN KPI tool, which has been developed at the research center for zero emission neighbourhoods in smart cities (FME ZEN) between 2017 and 2024. The tool empowers users to track, report, and visualize the performance of a zero emission neighbourhood throughout both the strategic planning and the implementation phases. It encompasses various KPIs across six categories: greenhouse gas (GHG) emissions, energy, power, urban form and land use, mobility, and economy. Within this guide, you will find a detailed, step-by-step explanation for effective use of the ZEN KPI tool.publishedVersio
Optimal control of a bio-based phase change material thermal energy storage for demand response
Full text linkIn this study, the design and development of an optimal control strategy for the operation of an innovative bio-wax phase change material based pillow plate thermal energy storage unit delivering space heating to a four-storey-high research building is presented. The hydronic heating system in the ZEB-laboratory comprises an electric driven heat pump, the thermal storage unit and hydronic radiators. Numerical control-oriented dynamic models to simulate the phase-change dynamics of the thermal system are developed and validated. To predict the hourly heating load of the building reliably and accurately, a 14-node Resistance–Capacitance thermal network model is developed to be employed as a decision support tool. An optimal model-based predictive control strategy based on the validated system models is developed for application in real-time operation of the thermal storage unit. The control strategy is designed to optimally utilize the energy storage capability of the thermal energy storage unit to generate demand flexibility in response to time-varying electricity price signals. In comparison to a rule based control, the developed optimal control demonstrates a high degree of flexibility – as quantified by values of flexibility factor close to 1 being obtained – indicating a system operating with maximum flexibility, during one month of operation. Further, results demonstrate the availability of storage capacity of 100 kW h–200 kW h per day on average, indicating the capability of the optimized operation of the thermal energy storage unit to provide grid ancillary services. In addition to being demand flexible, the optimal charging schedule reduces the energy consumption and cost by about 40% – 50% on average. Thus, the developed optimal control strategy demonstrates a significant capability to generate and maximize demand flexibility to shift loads intelligently, provide grid services, and reduce energy cost and consumption. © 2024 Author keywords Demand flexibility; Optimal control; Phase change material; Thermal energy storageOptimal control of a bio-based phase change material thermal energy storage for demand responsepublishedVersio
Resource-Efficient and Climate-Friendly Design of Concrete Structures Through Advanced Structural Safety Concepts
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Non-contact interactance NIR spectroscopy for estimating TSS and sensory sweetness in conveyor-belt transported cherry tomatoes (Lycopersicon esculentum ’Piccolo’)
Full text linkSweetness in tomatoes is a crucial quality feature, especially for high-cost varieties. Without efficient measurements, producers cannot guarantee sweetness, which may lead to low repurchase rates and increased food waste. In this article we report how total soluble solids (TSS), a measure for total sugar content, can be measured in cherry tomatoes using non-contact near-infrared (NIR) interactance spectroscopy. A prototype system working in the wavelength range 760–1080 nm was tested and compared with a commercial handheld NIR reflection instrument operating in the range of 909–1676 nm. The instruments were calibrated using data collected from 200 tomatoes and tested on 5 independent sets harvested over the next 14 months, a total of 611 single tomatoes and 22 tomato trusses. TSS for single tomatoes was in the range 5.3–14 %. NIR interaction obtained typical standard errors of prediction in the range 0.38–0.52 %, significantly lower (p < 0.05) compared to NIR reflection (0.70–0.98 %). Approximately the same accuracy was obtained by interaction measurements on tomatoes moving on a conveyor belt, both in lab (0.47–0.53 %) and in industry (0.39 %). Whole tomato trusses were measured in movement, and TSS could successfully be measured in each tomato on the truss. Three of the test sets were subjected to sensory analysis performed by a trained panel of 10 assessors, revealing high correlations (0.88 – 0.99) between sensory sweetness and NIR estimated TSS. The results demonstrate that a carefully designed NIR interaction instrument can be used for rapid and non-contact monitoring and sorting of cherry tomatoes according to sweetness.publishedVersio
SIMLA module SimVis - User Guide
Full text linkThis report contains a guide on how to set up and use the SimVis module in context of the SIMLA program system. The guide covers how to generate a SimVis terrain database with SIM Scenery Creator and how to set up and use the SimVis module, both standalone and as a 3D visualization tool for viewing of results from SIMLA analyses.SIMLA module SimVis - User GuidepublishedVersio
Topography-based surface water modeling in Julia, with support for infiltration and temporal developments
Full text linkSWIM (Surface Water Integrated Modeling) is a Julia software package for static modeling and prediction of surface water and urban flooding based on analysis of terrain topography, terrain properties, and infrastructure.
SWIM consists of a collection of algorithms for analyzing terrain, identifying watershed boundaries, and providing a better understanding of how water accumulates and moves across the landscape. Such analyses are valuable for various purposes, including water resource management, flood modeling and mitigation, and environmental planning.
The algorithms are based on the assumption of infinitesimal flow and the identification of spill points. Spill-point analyses are highly computationally efficient compared to tools based on numerical simulation, making it easy to work interactively and test out various scenarios and measures. SWIM offers unique functionality, such as simplified infiltration models for both permeable and impermeable surfaces, as well as the calculation of time series that model how water accumulates or drains over time without resorting to computationally intensive numerical time-stepping approaches.publishedVersio
An Engineering Equation for Thermal Ice Loads on Dams
Full text linkThis research project was jointly financed through the project Dam Safety in a Holistic Perspective (DHSP) and the Norwegian Water Resources and Energy Directorate (NVE). The goal was to derive an engineering-friendly assessment of thermal ice loads on dams based on an energy-conserving ice growth model and published relationships between ice temperature changes and compressive stress. This report presents both a probabilistic and a deterministic approach to the problem and presents associated design solution. Key results include a physically-based justification for the shape of the ice load equation, and the presentation of an ice load probability distribution that accounts for ice-free years. It is suggested that further improvements to ice load predictions consider regional differences of the snow cover. Also, the data basis of measured thermal ice loads should be improved in Norway.An Engineering Equation for Thermal Ice Loads on DamspublishedVersionpublishedVersio
Impact of water leaching of biomass on the composition of torrefaction condensates
Full text linkThis work has been carried out to demonstrate the effect of water-leachable biomass components on the liquid product distribution of torrefaction. For the partial removal of the mineral matter, each biomass feedstock was leached with hot water. The original and leached wheat straw, rape straw and black locust wood as non-food agricultural and forestry waste samples were torrefied within the temperature range of 200–300 °C. The composition of the collected torrefaction condensates as liquid products was determined from solution by GC/MS and the compositional differences were evaluated. The analysis of the torrefaction condensates allowed us to reveal the effects of water-soluble inorganic contents on the thermal decomposition processes, the yield, and the compositional changes as a function of the applied temperature. Formation of 5-hydroxymethylfurfural (HMF) was detected from the unleached black locust wood and rape straw samples at as low as 200 °C apparently formed by dehydration of the extractable sugar content. Aromatic compounds derived from lignin were released in a significant amount at and above 225 °C. The formation of these decomposition products was hindered from the water-leached samples below 250 °C. In the cases of leached samples, depolymerization of both cellulose and hemicellulose was favored contrary to fragmentation processes within the temperature range of torrefaction similarly to pyrolysis at higher temperatures. The influence of water-leachable inorganic content was also shown on the formation of lignin decomposition products with different side-groups. Interaction between the organic components of biomass was exemplified by the thermal reaction of the lipid content with the methoxy groups of lignin resulting in the formation of methyl palmitate. © 2025 The AuthorspublishedVersio
Effects of climate change and anthropic water uses on ecosystem services provided by an Alpine river
Full text linkSeveral Alpine river ecosystem services (ES) depend on the streamflow regime, thus they might be affected by multiple stressors such as changing climate and anthropic water uses, with still poorly investigated consequences. We focused on the supply of three ES in an Alpine river, namely habitat provision, recreational activities, and hydroelectricity production from run-of-the-river (RoR) power plants. We applied an integrated hydrological, hydraulic and habitat modeling approach to quantify the effects of climate change (CC) on these services, based on the outcomes of four regional climate models. The paper investigated the effects of water use policies such as the introduction of prescriptions for environmental flow (EF) under the same CC models. We observed that CC significantly affects the river suitability for the supply of ES at the catchment scale, while the introduction of EF releases are relevant at a more local scales (several reaches). Under future scenarios, simulated increasing abstractions for hydroelectricity production from RoR power plants have a stronger effect on white-water rafting and a relatively smaller effect on fish habitat. Quantifying the potential effects of CC and of different strategies of river flow management under these scenarios is a promising approach to support the design of long-term water resources management strategies at catchment and local level.Effects of climate change and anthropic water uses on ecosystem services provided by an Alpine riverpublishedVersio