Zero Emission Buildings Research Articles

Review of the Current State of Development of the Progress Indicators in National Long-Term Renovation Strategies

The Commission Recommendation (EU) 2019/786 created a clear path towards a low and zero-emission building stock by 2050, based on milestones and progress indicators. National Long-Term Renovation Strategies (LTRS) are required to ensure the renovation into energy efficient and decarbonised buildings. This paper reviews the current status of the development of the progress indicators carried out by the Member States.

Performance investigation of a net-zero energy building in hot summer and cold winter zone

The net-zero energy building (NZEB) is spreading rapidly as an integrated solution to address energy saving and carbon emissions reduction in the building sector. However, few studies pay close attention to the operational performance of NZEBs as well as their life cycle impact on the environment. This study investigates the operational performance of NZEBs, analyzes the influence factors in achieving net-zero energy, and explores the pathway to reduce the building life cycle carbon emission via a case study conducted from March 2017 to February 2018 in the hot summer and cold winter climate zone of China. The one-year investigation results show that the case building, where energy-efficient technologies and renewable energy were integrated, achieved net-zero energy with good indoor environmental quality. Based on the investigation, influence factors in achieving net-zero energy were analyzed via DesignBuilder: the minimum area per capita was 42 m 2 /person under the circumstance of net-zero energy; when operational strategy was changed, the air-conditioning energy use reduction was less than 5%. Additionally, in order to achieve net-zero energy, an equation was proposed to estimate the area ratio of installed photovoltaic (PV) panels to that of the building roof, thereby providing guidance for NZEBs design. Furthermore, life cycle carbon emissions of the project were evaluated. Based on the foregoing results, it can be concluded that by increasing carbon offsets of the PV system appropriately, an NZEB can be transformed into a life-cycle zero-emission building. Moreover, it is necessary to mention that the life cycle carbon emissions of the PV system should be considered. • Efficient technology and renewable energy are integrated to achieve net-zero energy. • Indoor environment quality is kept within comfort range with low energy used. • Influence factors in achieving net-zero energy is analyzed. • A net zero-energy building can achieve zero emission throughout the life cycle. • Life cycle carbon emissions of PV system deserve consideration.

Design Options to Improve the Dynamic Behavior and the Control of Small H-Darrieus VAWTs

H-VAWTs or straight blades VAWTs are the most common turbine architecture employed for small VAWTs. The manufacture of straight, constant chord blades, coupled with the transport advantages, make this choice technologically simpler, compared to curved (eggbeater) type or curved-bent (Gorlov) type, allowing a large selection of materials, and design solutions. Recently, the strategies to accomplish the task of zero-emission buildings identified wind energy exploitation in the urban environment as one of the most promising. Micro and mini wind turbines installed on buildings (BAWT—building-augmented wind turbines) are considered the candidate technology after that of photovoltaic panels; under certain conditions, these technologies can be combined to obtain the maximum natural resources exploitation in the urban environment. VAWT, compared to HAWT, would ideally perform better in the fast-changing, turbulent winds, typical of the built environment. Additionally, its 3D shape favors a better architectonic integration with the volumes of the building. Nevertheless, despite these claimed advantages, this architecture did still not come to the expected fruition and experience, which revealed that the stochastic nature of the wind resource in the built environment determines a quite challenging context, reflecting not only the structural endurance, but also the operations and the annual energy production. These site characteristics stress the detrimental effect of the high polar inertia of this architecture hampering, be it a reduction in the acceleration and deceleration capability of the rotor, the required adaptation of the rotational speed to the varying wind conditions, or compromising any form of robust control. This leads to poor aerodynamic performance and potential structural damages. This paper contributes to mitigating the issue of the high rotor polar inertia of the H-VAWT without affecting other essential design requirements (strength, performances, needs of smooth control). The work identifies the design parameters governing the rotor acceleration and deceleration and develops a rational design procedure aimed at improving the H-VAWT control and performance.

Experimental investigation and performance assessment of a solar-driven thermoelectric unit for localized heating and cooling applications

Heating, ventilation, and air conditioning systems help maintain the appropriate level of thermal comfort and air quality in buildings. To this end, the energy supply of these systems must be guaranteed. However, continuous efforts are required to improve the energy efficiency of this system and reduce greenhouse gas emissions. In the zero-emission building approach, the use of thermoelectric devices has been proposed to meet the heating/cooling needs in the building and help in flexibly changing the operating conditions according to the user's needs. In this study, an experimental setup was developed consisting of a multipurpose thermoelectric system that is directly powered by a solar photovoltaic panel. The heating mode was designed for space heating, whereas the cooling mode was tailored to an adiabatic box that could cool food and beverages. The results of this study will facilitate the practical use of this device in the future by directly connecting the thermoelectric system to the room and evaluating the response of the system to temperature changes requested by the user. This system has a high potential for delivering heating and cooling loads, achieving a coefficient of performance of 1.6 in the heating mode and 0.8–1.1 in the cooling mode. These results are promising given the current need to reduce negative environmental impacts in the building sector yet maintaining the same level of thermal comfort.

A stochastic operational planning model for a zero emission building with emission compensation

The primary objective of Zero Emission Buildings (ZEBs) is to achieve net zero emission over the buildings’ lifetime. To achieve this goal, accurate cost-effective emission compensation is needed during the operational phase. This paper presents a stochastic planning model comprising an emission inventory for the operation of ZEBs. The operational planning methodology uses stochastic dynamic programming (SDP) to analyze and represent the expected future cost curve (EFCC) for operation based on the electricity price and accumulated CO2eq-inventory during the year. Failing to compensate for net zero emission makes the leftover amount subject to a penalty cost at the end of the year. This renders the overall problem multi-objective optimization including emission compensation and cost of operation. The model is applied to a case study of a Norwegian building, tested for a range of penalty costs for leftover CO2eq-inventory. The results show that, for a ZEB, including emission compensation demonstrates a significant impact on the operation of the building. The penalty cost puts a limit on how much the operational cost increase for additional compensation should be, influencing the end CO2eq-inventory. Increasing penalty costs decreases the end inventory, and a penalty cost of 10 EURkgCO2eq resulted in zero emission. The case achieving zero emission had an operational cost increase of 4.8% compared to operating without a penalty cost. This shows the importance of accounting for emissions during the operation of a ZEB, and the value of having an operational strategy that presents the future impact of operation.

Large potentials for energy saving and greenhouse gas emission reductions from large-scale deployment of zero emission building technologies in a national building stock

High energy and material demand in the building sector causes large greenhouse gas (GHG) emissions. This sector needs large-scale technological improvements in the transition to a future low-emission society. Extensive research is carried out on highly energy-efficient and zero emission buildings (ZEB), but the new technologies slowly penetrate the market. Until now, no bottom-up studies have applied a dynamic building stock energy model at the national level to quantify effects of a large-scale ZEB introduction. Using the RE-BUILDS 2.0 model, we explore and extensively discuss the aggregated potential for energy and GHG emission savings in the Norwegian building stock towards 2050. A Baseline scenario is compared with two ZEB scenarios assuming introduction of the ZEB definition and ZEB technologies applied in the future new built and renovated buildings, with an increased ambition level over time. The results reveal a large potential for energy and GHG emission savings of ZEB deployment towards 2050. Hence, stricter future regulations and practice will have important aggregated effects. Due to the long lifetime of buildings and potential lock-in effects, it is urgent that ZEB policies are implemented if the climate change mitigation potential of the Norwegian building stock is going to be reached.

A Study on Introduction of Hydrogen Utilization System for Zero Emission Buildings

A Study on Introduction of Hydrogen Utilization System for Zero Emission Buildings

The Study of Facial Muscle Movements for Non-Invasive Thermal Discomfort Detection via Bio-Sensing Technology. Part I: Development of the Experimental Design and Description of the Collected Data

In the time of climate change, as heat waves become a more regular occurrence, indoor thermal comfort is an important factor in day to day life. Due to such circumstances, many researchers have focused their studies on finding an effective solution that will not only enable thermal comfort, but also increase satisfaction within the indoor environment and, as a result, productivity. The fast development of the biometrical field encouraged the study focused on the investigation of how bio-markers, in combination with artificial intelligence algorithms, can be collected within an experimental setting to create a new approach for non-invasive thermal discomfort detection. The developed experimental design provides synergy between automatic facial coding, pulse, and galvanic skin response measurements via iMotions software in a controlled environment. The iMotions software has built-in machine vision algorithms, and with Shimmer sensors and a post-processing tool through Affectiva AFFDEX, is able to collect facial action data through detection of the facial muscle movements and various bio-markers. The Zero Emission Building (ZEB) Test Cell laboratory was used as the control environment and transformed to imitate an office space for the data collection campaign at NTNU in Trondheim. The given experimental design provides an opportunity to create an immense database with bio-markers that are linked to the subcortical level of the brain, indoor parameters, and direct feedback on the comfort level of occupants within an office-like environment. In total, 111 data collection sessions were registered with iMotions. The discomfort button was pressed 240 times and 1080 planned indoor comfort evaluation surveys were held during experiment. The discomfort button was pressed 49 times to indicate that participant felt discomfort due to low temperature and 52 due to high temperature. Collected data revealed a big deviation in the discomfort temperature values for experiment participants with respect to performed temperature ramps. While it is common to use the same predefined temperature range for facility management, it became clear that the complexity of the task is greater and should not be approached on a human computational level. Implementation of AI can potentially provide higher value accuracy within thermal discomfort detection and enable unique personal user experience at the workplace.

(Net-) zero-emission buildings: a typology of terms and definitions

Several different definitions of ‘net-zero’ or ‘climate-neutral’ buildings have arisen and are causing confusion. Different approaches quantify the greenhouse gas (GHG) emissions of buildings over their life-cycle. A typology is proposed based on distinctions between absolute and net-zero-emission buildings in relation to operational and full life-cycle approaches. Besides the absolute zero-emission approach, three different net-zero-emission approaches are: (1) a net-balance approach, which includes credits caused by potentially avoided emissions beyond the system boundary provided by exported energy; (2) an offsetting approach, based on the purchase of CO2 certificates; and (3) a technical approach, based on negative-emission technologies. The declaration of the approach chosen will provide clarity when discussing (net/absolute)-zero emission or climate-neutral buildings. Policy relevance The use of suitable terms, definitions, system boundaries as well as calculation and assessment rules is a prerequisite for credibility and transparency. Legal requirements for limiting GHG emissions from buildings and their fulfilment should therefore be formulated in a way that is understandable by both industry professionals and stakeholders with clear rules for documentation and the provision of evidence. This is particularly important for the proof of the political goal to create a climate-neutral building stock. A typology of (net-) zero building approaches is presented that explains their level of ambition, fosters transparency, and reduces misperceptions and misunderstandings.

Parametric Design to Maximize Solar Irradiation and Minimize the Embodied GHG Emissions for a ZEB in Nordic and Mediterranean Climate Zones

This work presents a validated workflow based on an algorithm developed in Grasshopper to parametrically control the building’s shape, by maximizing the solar irradiation incident on the building envelope and minimizing the embodied emissions. The algorithm is applied to a zero-emission building concept in Nordic and Mediterranean climate zones. The algorithm enables conducting both energy and environmental assessments through Ladybug tools. The emissions embodied in materials and the solar irradiation incident on the building envelope were estimated in the early design stage. A three-steps optimization process through evolutionary solvers, such as Galapagos (one-objective) and Octopus (multi-objective), has been conducted to shape the most environmentally responsive ZEB model in both climates. The results demonstrated the replicability of the algorithm to optimize the solar irradiation by producing an increment of solar incident irradiation equal to 35% in the Mediterranean area, and to 20% in the Nordic climate. This could contribute to compensate the additional 15% of emissions due to the higher quantities of employed materials in the optimized design. The developed approach, which is based on the parametric design principles for ZEBs, represents a support instrument for designers to develop highly efficient energy solutions in the early design stages.

Conversion of Residential Building into Green Building by using Thermal Properties of Cow Dung

Abstract This study focuses on converting a normal building with emission into a green building or zero emission building. The need of the green building is the need of the time. Building such things now would be more costly as conversion of the old buildings would be more profitable. Solar energy is one of the first resources that strike the mind after listening green building. Use of PV modules to fulfil the need has been focused in this paper. Using solar energy for fulfilling daily household needs is one of the major factors in making a house a green building. Another thing that has been focused in this paper is about the thermal comfort that is achieved by maintaining room temperature. Insulation was the major factor in doing this. Adding another layer of insulation in the walls of a house can prevent heat exchange from outside and thus helps in maintaining the temperature of room. And finally the reduced value of heat transfer coefficient was achieved along with the increased value of resistance. Keywords: PV modules, solar energy, thermal comfort, renewable energy, TERI, GRIHA Cite this Article Subodh Kumar, Palash Shriwastava, Pankaj Jain. Conversion of Residential Building into Green Building by using Thermal Properties of Cow Dung. Journal of Thermal Engineering and Applications . 2020; 7(1): 1–8p.

Annulus eccentricity optimisation of a phase-change material (PCM) horizontal double-pipe thermal energy store

Abstract The application of phase-change materials (PCMs) has received significant interest for use in thermal energy storage (TES) systems that can adjust the mismatch between the energy availability and demand. In the building sector, for example, PCMs can be used to reduce air-conditioning energy consumption by increasing the thermal capacity of the walls. However, as promising this technology may be, the poor thermal conductivity of PCMs has acted as a barrier to its commercialization, with many heat-transfer enhancement solutions proposed in the literature, such as microencapsulation or metal foam inserts, being either too costly and/or complex. The present study focuses on a low-cost and highly practical solution, in which natural-convective heat transfer is enhanced by placing the PCM in an eccentric annulus within a horizontal double-pipe TES heat exchanger. This paper presents an annulus-eccentricity optimisation study, whereby the optimal radial and tangential eccentricities are determined to minimize the charging time of a PCM thermal energy store. The storage performance of several geometrical configurations is predicted using a computational fluid dynamics (CFD) model based on the enthalpy-porosity formulation. The optimal geometrical configuration is then determined with response surface methods. The horizontal double-pipe heat exchanger studied considered here is an annulus filled with N-eicosane as the PCM for initial studies. In presence of N-eicosane, for the concentric configuration (which is the baseline case), the charging is completed at Fo = 0.64, while the charging of optimum eccentric geometries with the quickest and slowest charging is completed at Fo = 0.09 and Fo = 2.31, respectively. In addition, an investigation on the discharging performance of the studied configurations with N-eicosane shows the quickest discharge occurs with the concentric annulus case at Fo = 0.99, while the discharge time of the proposed optimum annuli is about three times this value. In other words, the proposed optimum geometry with the quickest charging time charges ~7.1 times faster but also discharges ~3 times slower, which is ideal for a TES, especially when used as passive thermal storage systems in nearly zero-emission buildings. Complementary studies demonstrate that the proposed optimum configuration improves the TES performance also when employing other PCM types as well as various shell-to-tube diameter ratios.

Latent heat storage for centralized heating system in a ZEB living laboratory: integration and design

The ZEB Lab project, coordinated by SINTEF and NTNU, aims at building a ZEB (Zero Emission Building) in Trondheim (Norway) in 2019, to be used both as office building and living laboratory. An innovative latent heat storage (LHS) unit using phase change material (PCM) will be integrated in the centralized heating system. The LHS unit will be able to store excess heat from various heat sources connected to the heating system, when they are not required for space heating. One challenge is to make use of the full potential of the PCM latent heat to have a compact and effective unit, while the unit itself should have a low associated CO2-footprint. The LHS system consists of two units designed for a total heat storage capacity of 0.6 MWh, corresponding to the heat needed on top of the heat pump to cover for up to 3 consecutive days in the coldest period of the year, with a maximum combined effect of 26 kW. A bio-based wax is used as PCM with melting temperature 37 °C and measured latent heat 198 kJ/kg. Dynamic system modelling is used to support the design of the LHS unit and ensure sufficiently high heat transfer rates.

The Norwegian ZEB definition and lessons learnt from nine pilot zero emission building projects

In the frame of the Norwegian Research Centre on Zero Emission Buildings, nine real-life zero emission pilot building projects were initiated during the period of 2009 to 2017. Eight of the pilot building projects have been constructed and are currently in use, whilst one of them is still in the planning phase. All the pilot projects have been followed up by researchers during the design, construction, and operation phases, by e.g. analyses of construction documents, and post-occupancy surveys. The main lessons learnt from this work are presented in this paper. They include the importance of an integrated design process, having clear goals and associated assessment methods, following a strategy based on ‘trias energetica’, as well as choosing locally sourced materials with low embodied carbon and long service lives, and increasing the focus on the users.

Life cycle assessment for Zero Emission Buildings – A chronology of the development of a visual, dynamic and integrated approach

Current regulations to reduce energy consumption, and GHG emissions from buildings have focused on reducing operational impacts [1] This paper addresses the specific challenge of increasing complexity and decreasing usability when dealing with the level of detail required when modelling life cycle assessment (LCA) and integrating embodied emission calculations in the design process of a ZEB. It is well known that architectural design processes inherently have high degrees of complexity, and this paper investigates how the use of information and communication technology (ICT) in the design process can have a great impact on reducing GHG emissions and increasing sustainability in ZEBs. Visualisation is an invaluable tool to communicate complex data in an interactive way that makes it easier for non-expert users to integrate LCA thinking early and throughout the design process.The paper presents a chronology in the development of a more visual, integrated and dynamic approach involving the use of parametric LCA models for decision-support purposes. Such an approach provides the designer with a direct link between the 3D digital model and embodied emissions data contained in the ZEB Tool to perform life cycle GHG emission calculations of buildings. Integrating LCA in a more visual and easily understood way in the holistic design process can also influence more tangible material choices in terms of, for example, architectural tectonics or cultural heritage. This allows designers the possibility to choose, for example, durable or natural materials with the lowest environmental impact or innovative materials with high or low associated emissions and consider these holistically early in the design phase when the level of design freedom is greater. The extent to which existing ICT tools and User Interfaces (UI), such as dashboards, can provide dynamic visual feedback on selected parameters, including LCA, in the design process of zero emission buildings, is discussed. The paper presents two ‘proof of concept’ dashboards to visualise LCAs at the building (ZEB) and neighbourhood (ZEN) scale. Both approaches are currently being further developed in The ZEN research centre to visualise, analyse and model the data at different scales for different ZEN Key Performance Indicators (KPIs) using visualisation and immersive technologies, such as Extended Reality (XR) technologies including Virtual Reality (VR) and Augmented Reality (AR).

Simulation and control of shading systems for glazed facades

This paper presents a simulation study on the use of shading devices in highly glazed facades in the context of zero emission buildings (ZEB) located in a Nordic climatic context. Shading devices have the task to control different uses of solar energy (solar gain for passive solar heating and daylighting) and to avoid cooling load, and to find the best strategy (i.e. to optimize the overall performance) for controlling shading devices is not trivial.Different control strategies for the activation of the shading devices (venetian blinds) are simulated, and their performance calculated in this study through a dynamic whole-building simulation tool (EnergyPlus). The results of the simulation studies show that it is possible to achieve very high performance and balanced use of solar energy (for passive solar heating, daylighting), without occurring in too high cooling load, even in the case of fully glazed facades. The optimal strategy for shading activation is not straightforward, and different strategies should be recommended during the year to assure an overall optimal performance.

Relation between daylight availability and electric lighting in a single-family house

Daylight availability is an important aspect that can potentially improve both the quality and the energy performance of buildings. However, it is not always straightforward easy to assure that an increase in the daylight availability leads to a reduction of electric energy use for artificial lighting. In this study, experimental measurements and numerical simulations were conducted to analyse the relation between the uses of artificial light and the daylighting availability for different groups of users who lived for one month each in a Zero Emission Building single-family house located in Trondheim, Norway. The use of electric lighting and the outdoor environment conditions (irradiance and illuminance on the horizontal plan) were recorded through advanced daylighting simulations, carried out with DIVA-for-Rhino, the daylighting availability during the periods of occupancy was then reconstructed, using as input data the outdoor environmental variable recorded during the experimental analysis. The results show that the coefficient of correlation between daylight availability and the artificial light is in general low and the use of artificial lighting seems to be largely independent from the availability of natural light.

Effect of Ultraviolet Radiation on Organic Photovoltaic Materials and Devices.

Organic photovoltaics are a sustainable and cost-effective power-generation technology that may aid the move to zero-emission buildings, carbon neutral cities, and electric vehicles. While state-of-the-art organic photovoltaic devices can be encapsulated to withstand air and moisture, they are currently still susceptible to light-induced degradation, leading to a decline in the long-term efficiency of the devices. In this study, the role of ultraviolet (UV) radiation on a multilayer organic photovoltaic device is systematically uncovered using spectral filtering. By applying long-pass filters to remove different parts of the UV portion of the AM1.5G spectrum, two main photodegradation processes are shown to occur in the organic photovoltaic devices. A UV-activated process is found to cause a significant decrease in the photocurrent across the whole spectrum and is most likely linked to the deterioration of the charge extraction layers. In addition, a photodegradation process caused by UV-filtered sunlight is found to change the micromorphology of the bulk heterojunction material, leading to a reduction in photocurrent at high photon energies. These findings strongly suggest that the fabrication of inherently photostable organic photovoltaic devices will require the replacement of fullerene-based electron transporter materials with alternative organic semiconductors.

Construction and operation of hydrogen energy utilization system for a zero emission building

A bench-scale stationary hydrogen energy utilization system with renewable energy (RE) that realizes a zero emission building (ZEB) is presented. To facilitate compactness, safety, and mild operation conditions, a polymer electrolyte membrane (PEM) electrolyzer for hydrogen production (5 Nm3/h), PEM fuel cells (FC) for hydrogen use (3.5 kW), and metal hydride (MH) tanks for hydrogen storage (80 Nm3) are incorporated. Each hydrogen apparatus and Li-ion batteries (20 kW/20 kWh) are installed in a 12-ft. container and 20-kW photovoltaic panels provide power. A building energy management system (BEMS) controlled these system components in an integrated manner. The PEM Ely and FC have fast start-up and high efficiency under partial load operations, indicating suitability for daily start-stop operations. An AB-type TiFe-based alloy (520 kg) is used as the MH (not an AB5-type rare earth alloy that has been commonly used in bench-scale hydrogen store) because, in addition to being low-cost, it is non-hazardous material under Japanese regulations. The results of a 24-h operation experiment verify ZEB attainment. PEM FC and TiFe-based tanks thermal integration results indicate that hydrogen use operation is achievable without external heat sources.

Homemaking in a Living Laboratory: Interpretations of a Zero Emission Housing Solution

A zero emission building (ZEB), as defined by the Research Centre on Zero Emission Buildings (ZEB Centre) in Norway, is one solution towards achieving the aims set by the Paris Climate Agreement on dramatically reducing carbon emissions. The structure for a zero emission building includes a variety of technical strategies such as passive and active energy design and renewable energy sources, and is currently under development and testing. Many of the future ZEBs will become homes, implying a change in the use and understanding by those living there. Based on the response from six residential groups who lived in ZEB Living Lab, this paper studies how zero-emission housing technology impacts the use and understanding of it as a home. The paper presents two different interpretations, one that felt at home, and one that did not, and discusses the reasons and implications on the wider use and introduction of this kind of housing technology in Norway.