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  • 1.
    Blomqvist, Claes
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Conversion of Electric Heating in Buildings: an Unconventional Alternative2008In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 40, no 12, p. 2188-2195Article in journal (Refereed)
    Abstract [en]

    To decrease the electric energy used for heating buildings it has become desirable to convert direct electrical heating to other heat sources. This paper reports on a study of the possibility of using an unconventional method for conversion to avoid installing an expensive hydronic system. The conversion method combines the ventilation and heating systems and uses air instead of water for distribution of heat within the building, taking advantage of thermal forces and the special properties of gravity currents. Full-scale tests have been carried out in a test apartment inside a laboratory hall where the conditions could be controlled. Temperatures and efficiency of ventilation have been measured to ensure that the demands with respect to thermal climate and air exchange were fulfilled. The results show that it is possible to use the method for heating and ventilation when converting the heating system, but further work has to be done to develop a detailed solution that works in practice.

  • 2. Erell, E
    et al.
    Etizon, Y
    Carlstrom, N
    Sandberg, Mats
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Molina, J
    Maestre, I
    Maldonado, E
    Leal, V
    Gutschker, O
    "SOLVENT": development of a reversible solar-screen glazing system2004In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 36, no 5, p. 467-480Article in journal (Refereed)
    Abstract [en]

    Preliminary experiments with a novel glazing system developed at the Desert Architecture and Urban Planning Unit of Ben-Gurion University of the Negev in Israel indicated that it may provide improved visual and thermal performance in buildings with large glazed areas located in sunny regions, regardless of orientation. In winter, it reduces glare, local over-heating and damage to furnishings caused by exposure to direct solar radiation, with only a small reduction in solar space heating. In summer, it reduces the penetration of unwanted radiation without obstructing the view through the window, to an extent that may render external shading devices unnecessary. The SOLVENT project was contracted to complete the development of the glazing system, which is based on the concept of converting short-wave solar radiation to convective heat and long wave radiation. The glazing system was modeled and evaluated experimentally; a suitable frame was developed for it; and a design tool required for its application was developed. The current paper reports on physical modeling and experimental evaluation of the glazing system.

  • 3. Ghadimi, M.
    et al.
    Ghadamian, H.
    Hamidi, A. A.
    Shakouri, M.
    Ghahremanian, Shahriar
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Division of Energy Systems, Department of Management and Engineering, Linköping University, Sweden.
    Numerical analysis and parametric study of the thermal behavior in multiple-skin facades2013In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 67, p. 44-55Article in journal (Refereed)
    Abstract [en]

    The general aim of this research is contributed to the energy performance assessment of single storey multiple-skin facade. To cover this aim; multiple skin facade are studied by means of experiments and numerical simulation. In this research a numerical model for multiple-skin facades with mechanical and natural ventilation has been developed. The numerical model is two-dimensional and based on a cell centered volume method (CVM). As an improvement, radiation and convection are treated separately and by this means an innovative method is applied to calculate the view factors and heat transfer coefficients between surfaces and each cavity. Then the developed numerical model is validated using measurements from the vliet test building. However, there is no multiple-skin facade application in Tehran. Thus the model is used to assess the influence of different multiple-skin facade parameters in Tehran's climate conditions to show its effect on heat losses if this technology would be applied. As a consequence of the diversity of results, designer should be aware that multiple-skin facades do not necessarily improve the energy efficiency of their designs. (C) 2013 Elsevier B.V. All rights reserved.

  • 4.
    Gustafsson, Mattias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Gävle Energi AB, Gävle, Sweden.
    Karlsson, Björn
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Rönnelid, Mats
    Högskolan Dalarna.
    How the electric meter configuration affect the monitored amount of self-consumed and produced excess electricity from PV systems: case study in Sweden2017In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 138, p. 60-68Article in journal (Refereed)
    Abstract [en]

    This study evaluates how the principal function of bi-directional electric meters affects the monitored amount of self-consumed and produced excess electricity for dwelling buildings connected to the grid by three phases. The electric meters momentarily record the sum of the phases or the phases individually and then summarize the recorded values to a suitable time period and is then collected by the grid owner. In Sweden, both electric meter configurations fulfill laws and regulations.

    The meter configuration affects the monitored distribution of self-consumed and produced excess electricity significantly for the investigated single-family house but is negligible for the investigated multi-dwelling buildings. The monitored self-consumed electricity produced by the PV installation for the single-family house varies between 24% and 55% depending on the configuration and how the inverter is installed for the investigated year. The difference in economic value for the produced electricity varies between 79.3 to 142 Euros.

    Due to the electric meter configuration, the profitability of PV systems will be different for identical single-family houses with identical conditions. This should be corrected for a well-functioning market. It is also important to decide how the configuration should be designed to ensure that different incentives and enablers results in desired effects.

  • 5.
    Hayati, Abolfazl
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Mattsson, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Single-sided ventilation through external doors: measurements and model evaluation in five historical churches2017In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 141, p. 114-124Article in journal (Refereed)
    Abstract [en]

    Ventilation through open doors is a simple way to temporarily enhance ventilation of indoor spaces, with the purpose to evacuate indoor air pollutants or to adjust the indoor temperature. In churches and other historical buildings, which otherwise are ventilated only through air infiltration, temporarily enhanced ventilation through open doors or windows may be a prudent deed after e.g. services involving large congregations and burning of candles or incense. In the present study, the air exchange occurring at single-sided ventilation through the external doors of five historical churches is measured by tracer gas decay method. Further, air velocity measurements and smoke visualization in a doorway are performed. Measurement results are compared with predictions attained from four previously developed models for single‐sided ventilation. Models that include terms for wind turbulence yielded somewhat better predictions. According to the performed measurements, the magnitude of one hour single-sided open-door airing in a church is typically around 50% air exchange, indicating that this is a workable ventilation method, also for such large building volumes. A practical diagram to facilitate estimation of a suitable airing period is also presented. The study adds particularly knowledge to the issue of airing through doors, in large single zones.

  • 6.
    Hed, Göran
    et al.
    University of Gävle, Department of Technology and Built Environment.
    Bellander, R
    Mathematical modelling of PCM air heat exchanger2006In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 38, no 2, p. 82-89Article in journal (Refereed)
    Abstract [en]

    In order to cool a room with a cold night air phase change material, PCM, is stored in an air heat exchanger. During night the PCM crystallises, energy is released. During daytime air is circulated in the unit, energy is absorbed and the indoor air is cooled. The characteristic of PCM is that there is an increase of the specific heat over a limited temperature span. This is the principle that is used in the design of the PCM air heat exchanger unit. The action of a PCM storage unit will act differently depending of the thermal properties of the material. In an ideal material the phase transition occurs at a given temperature. On the market, compounds containing PCM are available which, in order to create a suitable melting temperature, are mixtures of different products. In these materials, the transition from liquid to solid takes place over a temperature span, i.e. the specific heat varies with the temperature. This can be represented by a c(p)(T) curve, specific heat as a function of the temperature. In this paper, the development of a mathematical model of the PCM air heat exchanger is presented. Considerations are taken to different shapes of the cp(T) curve. The mathematical model is verified with measurement on a prototype heat exchanger. The development of the equipment is part of the CRAFT project Changeable Thermal Inertia Dry Enclosures (C-TIDE) the possibility of use of phase change materials integrated into a building is explored. 

  • 7.
    Karami, Peyman
    et al.
    KTH.
    Twumasi Afriyie, Ebenezer
    KTH.
    Norberg, Peter
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering. KTH.
    Gudmundsson, Kjartan
    KTH.
    A study of the thermal conductivity of granular silica materials for VIPs at different levels of gaseous pressure and external loads2014In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 85, p. 199-211Article in journal (Refereed)
    Abstract [en]

    Fast and reliable methods for the determination of thermal properties of core materials for vacuum insu-lation panels (VIPs) are needed. It is of great importance to know the thermal performance of a VIP core atdifferent levels of vacuum and external loads. In this study a new self-designed device, consisting of twocylindrical cavities connected to a Transient Plane Source instrument, is used to determine the thermalconductivity of low-density nanoporous silica powders, from atmospheric pressure down to 0.1 mbarwhile applying different levels of external pressure up to 4 bars. The study includes a brief theoreticaldiscussion of methods. The TPS is validated through comparison with available data for commercial silicaas well as through independent stationary measurements with a hot plate apparatus and with a TransientHot Bridge method. The different materials illustrate clear but different trends for the thermal conductiv-ity as a function of the level of vacuum and external pressure. The analysis of experimental results showsthat the transient methods are less suitable for measuring the thermal conductivity of low-density sil-ica powders, especially for the cases when the density is less than a limit at which the heat transfer byradiation becomes dominant compared to pure conduction.

  • 8.
    La Fleur, Lina
    et al.
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Rohdin, Patrik
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Measured and predicted energy use and indoor climate before and after a major renovation of an apartment building in Sweden2017In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 146, p. 98-110Article in journal (Refereed)
    Abstract [en]

    This article presents a case study of a renovated Swedish apartment building with a common design built in 1961. The aim is to present numerical predictions, validation and evaluation of energy use and indoor climate for the building before and after renovation. Comprehensive field measurements were carried out before and after the renovation to be used as input data in the building energy simulation tool IDA ICE and for validation of model results. Indoor temperature is predicted with maximum standard deviation of 0.4 °C during winter. Annual heat demand is in good agreement with measurements. The building had an annual climate normalized district heat demand of 99.0 MWh before renovation and 55.4 MWh after, resulting in a 44% reduction. A slight under-prediction of the saving potential is noted, since the indoor air temperature has increased after the renovation. The results also show that assumptions of user behavior have significant impact on the energy-saving potential, and that choice of renovation measures, such as level of insulation, and efficiency of the ventilation heat recovery system need careful consideration. Choice of system boundaries also has a major effect on climate and resource impact from selected renovation measures. 

  • 9.
    La Fleur, Lina
    et al.
    Linköpings universitet.
    Rohdin, Patrik
    Linköpings universitet.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology. Linköpings universitet.
    Investigating cost-optimal energy renovation of a multifamily building in Sweden2019In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 203, article id 109438Article in journal (Refereed)
    Abstract [en]

    A significant reduction in energy use in the building stock is a major challenge for the future, and doing this in a cost-effective manner is important. This study uses an optimization approach to identify life cycle cost (LCC) optimal energy efficiency measures (EEMs) to implement as part of a renovation of a multifamily building in Sweden. The studied building is a multifamily building with a lightweight concrete construction and an exhaust air ventilation system, built in 1961. The optimization tool OPERA-MILP is used. The energy renovation approaches are compared to both the performed energy renovation of the building and a validated dynamic energy simulation model in IDA ICE 4.8. The results show that under the given framework conditions and assumptions it is not cost-optimal to improve the thermal performance of the building envelope or to implement heat recovery ventilation measures to reduce the space heating demand in the building when considering a life cycle of 40 years. Balanced mechanical ventilation system with heat recovery is cost-effective when an energy saving target of 40% is introduced. The energy renovation of the building has a slightly higher LCC than the cost-optimal level, and it would have been more cost-effective to add more insulation to the façade instead of the attic to achieve the same level of energy saving. A sensitivity analysis has been performed to reveal the effect of the discount rate, energy price, cost of EEMs, thermal properties of the building envelope and windows’ solar heat gain factors on the LCC.

  • 10.
    Larsson, Ulf
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Moshfegh, Bahram
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Sandberg, Mats
    University of Gävle, Department of Technology and Built Environment.
    Thermal analysis of super insulated windows (numerical and experimental investigations)1999In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 29, no 2, p. 121-128Article in journal (Refereed)
    Abstract [en]

    Windows are crucial for people's experience of the indoor climate, especially in the Nordic countries with cold climate and short days during the winter. This paper reports the first results from an ongoing research project focused on an improved integration of windows with the indoor air climate and people's perception of the windows. The thermal performance of a well-insulated window has been investigated both numerically and experimentally in a full scale test room. The window under consideration is a low-emissive triple-glazing window with two closed spaces filled with the inert gas krypton. An oxidised metal with low emissivity factor coats one pane in each space. Experimental and numerical investigations on the thermal performance of the window have been conducted for different winter cases. Temperature data obtained by direct temperature measurement using thermocouples and through numerical analysis are presented. The heat transfer through a window construction depends on three mechanisms i.e., conduction, convection and radiation. In this paper the convection-conducting mechanisms have been closely investigated. The numerical predictions agree well with the results from the measurements.

  • 11.
    Liu, Linn
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Division of Energy Systems, Department of Management and Engineering, Linköping University.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Division of Energy Systems, Department of Management and Engineering, Linköping University.
    Akander, Jan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Comprehensive investigation on energy retrofits in eleven multi-family buildings in Sweden2014In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 84, p. 704-715Article in journal (Refereed)
    Abstract [en]

    Rapidly growing energy use in the building sector is considered a serious problem by both the European Union (EU) and Sweden. Reducing energy demand in the building sector is important for Sweden in order to reach national energy goals for reduced energy use and CO 2 emissions in the future. This project aims to find energy efficiency potential in multifamily buildings in the Gävleborg region, which is a cold climate region in Sweden. Measurements and simulations have been made on eleven multifamily buildings from the whole region. The results include different energy efficiency measure packages, profitability analysis of individual measures and packages, and primary energy use analysis. The paper also includes CO 2 emissions reduction analysis based on different methods. The project shows that the multifamily buildings in the Gävleborg region have good potential to reduce their energy use by more than 50%, which in turn will contribute to 43% primary energy reduction and 48% CO 2 emissions reduction. 

  • 12.
    Liu, Linn
    et al.
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Sweden.
    Rohdin, Parrik
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Sweden.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Division of Energy Systems, Department of Management and Engineering, Linköping University, Sweden.
    Investigating cost-optimal refurbishment strategies for the medieval district of Visby in Sweden2018In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 158, p. 750-760Article in journal (Refereed)
    Abstract [en]

    This paper presents a methodology, using Life Cycle Cost (LCC) optimization and building categorization, to achieve a systematic study of the cost-optimal energy efficiency potential (CEEP) for 920 listed buildings in the medieval district of Visby in Sweden. The aim is to study the CEEP and CO2 emission reductions for this city that is included in the World Heritage List by UNESCO. The total CEEP is found to be 31% (20.6 GWh) resulting in a CO2 reduction of 57% (33.3 kton). The categorization method showed that the buildings could be divided in four clusters depending on building material, geometry and layout. The LCC analysis revealed that the energy efficiency measure packages were cluster specific. It is shown that multi-story wood buildings (Cluster II) have lowest specific LCC, and would arguably be the starting point for a renovation process. Presently most of the studied buildings are connected to the district heating (DH). The results show that heat pump (HP) and wood boiler (WB) is cost-optimal heating system for multi-story stone and wood buildings, respectively. In order for the DH to compete with HP and WB, the DH price needs to be reduced by 23% and 16%.

  • 13.
    Liu, Linn
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Rohdin, Patrik
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Evaluating indoor environment of a retrofitted multi-family building with improved energy performance in Sweden2015In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 102, p. 32-44Article in journal (Refereed)
    Abstract [en]

    The building sector within both the EU and Sweden accounts for about 40% of total energy use. It is therefore important to introduce energy efficiency measures in this sector in order to meet the national implementation of the Building Performance Directive. Retrofits that result in improved energy performance are important in order to meet national energy targets, but the impact on the indoor environment has to be considered. Properly chosen energy efficiency measures may affect the indoor environment positively. One retrofitted multi-family building, located in the city of Linköping, Sweden, was chosen as the study object. The building represents a common type of construction in Sweden. This study presents an evaluation of both the indoor environment and energy use of the retrofitted building in comparison with a similar non-retrofitted building from the same area. The results show that the building has potential to reach a 39% reduction of space heating demand. The indoor environment has been improved compared to the non-retrofitted building. Adding external blinds from 15 May to 15 September between 10am-12pm on the east side and 12pm-3pm on the west side seems to be the best option for improving the indoor climate during summer. 

  • 14.
    Liu, Linn
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Division of Energy Systems, Department of Management and Engineering, Linköping University, Sweden.
    Rohdin, Patrik
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Sweden.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Division of Energy Systems, Department of Management and Engineering, Linköping University, Sweden.
    LCC assessments and environmental impacts on the energy renovation of a multi-family building from the 1890s2016In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 133, p. 823-833Article in journal (Refereed)
    Abstract [en]

    The 2020 and 2050 energy targets increase requirements on energy performance in the building stock, thus affecting both listed and non-listed buildings. It is important to select appropriate and cost-optimal energy efficiency measures, using e.g. Life Cycle Cost (LCC) optimization. The aim of this paper is to find cost-optimal packages of energy efficiency measures (EEMs) as well as to explore the effects of specific predesigned energy target values for a listed Swedish multi-family building from the 1890s. The purpose is also to show the effects on energy use, LCC, primary energy use and CO2 emissions of different energy targets, discount rates, electricity prices and geographic locations. The results show that separate energy targets could be an effective way to simplify the implementation for listed buildings. Furthermore, a cost-optimal package of EEMs is more sensitive to changes in discount rate than in electricity price. The energy renovation has impact on the primary energy use and CO2 emissions. The lower the discount rate is, the more EEMs will be implemented and the easier the national energy targets may be achieved. A higher electricity price also leads to more EEMs being implemented but at the same time higher running costs. 

  • 15.
    Milić, Vlatko
    et al.
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Ekelöw, Klas
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Andersson, Maria
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology. Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Evaluation of energy renovation strategies for 12 historic building types using LCC optimization2019In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 197, p. 156-170Article in journal (Refereed)
    Abstract [en]

    The life cycle cost (LCC)optimization is a vital method when performing building energy renovation. The present paper provides an evaluation of cost-optimal energy renovation strategies for historic buildings using LCC optimization software OPERA-MILP. The evaluation is performed based on preset targets depending on LCC (LCC optimum)and energy use (decrease by 50%), where the environmental performance is also addressed. Twelve building types, which are typical of the historic building stock in Visby, Sweden, are used as the study object. The results show possible decreases of 12–38% in LCC when targeting LCC optimum. When targeting a 50% decrease in energy use, the LCC is decreased in 21 of 26 cases compared to before energy renovation. Cost-efficient EEMs on the building envelope are characterized by low renovation costs and additional insulation of building components with poor thermal properties. Furthermore, the environmental performance from the energy renovations is highly dependent on the chosen energy system boundary. 

  • 16.
    Twumasi Afriyie, Ebenezer
    et al.
    Kungliga tekniska högskolan (KTH).
    Karami, Peyman
    Kungliga tekniska högskolan (KTH).
    Norberg, Peter
    Kungliga tekniska högskolan (KTH).
    Gudmundsson, Kjartan
    Kungliga tekniska högskolan (KTH).
    Textural and thermal conductivity properties of a low density mesoporous silica material2014In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 75, p. 210-215Article, review/survey (Refereed)
    Abstract [en]

    In this study, the pore structure, tapped density and thermal conductivity properties of a new type of nanoporous silica material have been studied. We have applied nitrogen physisorption, high resolution scanning microscopy and Transient Plane Source thermal conductivity measurements to investigate these properties. The new mesoporous silica SNP have large BET surface area, 400–439 m2 g−1 and possess high porosity in the range of 95–97%. The results further show pore diameter centred at 43 nm or 47 nm for the two materials studied. Tapped densities as low as 0.077 g/cm3 have so far been obtained and the thermal conductivity of these materials has been measured to 0.0284 and 0.0294 W (m K)−1 at room temperature and atmospheric pressure. The effects of tapped density, pore size diameter and particle morphology on thermal conductivity are discussed.

  • 17.
    Yang, Bin
    et al.
    Department of Applied Physics and Electronics, Umeå University, Umeå, Sweden.
    Melikov, A.K.
    International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Denmark.
    Kabanshi, Alan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Zhang, C.
    Department of Civil Engineering, Aalborg University, Aalborg, Denmark.
    Bauman, F. S.
    Center for the Built Environment, University of California, Berkeley, CA, United States.
    Cao, G.
    Department of Energy and Process, Norwegian University of Science and Technology, KolbjørnHejesVei 1B, Trondheim, Norway.
    Awbi, H.
    School of Construction Management and Engineering, University of Reading, United Kingdom.
    Wigö, Hans
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Niu, J.
    School of Architecture, Design and Planning, The University of Sydney, Australia.
    Cheong, K. W. D.
    Department of Building, School of Design and Environment, National University of Singapore, Singapore.
    Tham, K. W.
    Department of Building, School of Design and Environment, National University of Singapore, Singapore.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Nielsen, P. V.
    Department of Civil Engineering, Aalborg University, Aalborg, Denmark.
    Kosonen, R.
    Department of Mechanical Engineering, School of Engineering, Aalto University, Espoo, Finland; College of Urban Construction, Nanjing Tech University, Nanjing, China.
    Yao, R.
    School of Construction Management and Engineering, University of Reading, United Kingdom.
    Kato, S.
    Institute of Industrial Science, The University of Tokyo, Tokyo, Japan.
    Sekhar, S. C.
    Department of Building, School of Design and Environment, National University of Singapore, Singapore.
    Schiavon, Stefano
    Center for the Built Environment, University of California, Berkeley, CA, United States.
    Karimipanah, Taghi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Li, X.
    Department of Building Science, School of Architecture, Tsinghua University, Beijing, China.
    Lin, Z.
    Division of Building Science and Technology, City University of Hong Kong, Hong Kong, Hong Kong.
    A review of advanced air distribution methods - theory, practice, limitations and solutions2019In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 202, article id 109359Article in journal (Refereed)
    Abstract [en]

    Ventilation and air distribution methods are important for indoor thermal environments and air quality. Effective distribution of airflow for indoor built environments with the aim of simultaneously offsetting thermal and ventilation loads in an energy efficient manner has been the research focus in the past several decades. Based on airflow characteristics, ventilation methods can be categorized as fully mixed or non-uniform. Non-uniform methods can be further divided into piston, stratified and task zone ventilation. In this paper, the theory, performance, practical applications, limitations and solutions pertaining to ventilation and air distribution methods are critically reviewed. Since many ventilation methods are buoyancy driving that confines their use for heating mode, some methods suitable for heating are discussed. Furthermore, measuring and evaluating methods for ventilation and air distribution are also discussed to give a comprehensive framework of the review.

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