| 1. |
- Jönsson, Åsa, 1965, et al.
(author)
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Life cycle assessment of flooring materials: Case study
- 1997
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In: Building and Environment. - 0360-1323. ; 32:3, s. 245-255
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Journal article (peer-reviewed)abstract
- The environmental impact of the three flooring materials linoleum, vinyl flooring and solid wood flooring during their life cycles was assessed and compared through life cycle assessment (LCA). The scenarios used describe a Swedish situation. Only impacts on the natural environment were studied The quantitative results of the inventory analysis were evaluated by using three different assessment methods. According to the results, solid wood flooring proved to be clearly the most environmentally sound flooring. Linoleum was ranked as more environmentally sound than vinyl flooring, although this was less evident in comparison with ranking the solid wood flooring.
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| 2. |
- Karimipanah, Taghi, 1953-
(author)
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Deflection of wall-jets in ventilated enclosures described by pressure distribution
- 1998
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In: Building and Environment. - 0360-1323 .- 1873-684X. ; 34:3, s. 329-333
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Journal article (peer-reviewed)abstract
- The pressure field in fluid systems reflects the flow configuration. Measurements of the pressure along the perimeter of a slot ventilated room have been conducted for different room sizes. The momentum of the jet at the end of the room is decreased with increasing room length. The impingement region (region where the influence of the opposing wall is present) starts, independent of room size, when the distance from the supply device is about 70% of the room length. Corner flows could not be predicted by CFD using the linear eddy viscosity or standard stress models. However, these effects may be captured by using a second moment closure turbulence model with a new near wall approach now available in literature.
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| 3. |
- Karimipanah, Taghi, 1953-, et al.
(author)
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Theoretical and experimental investigation of impinging jet ventilation and comparison with wall displacement ventilation
- 2002
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In: Building and Environment. - 0360-1323 .- 1873-684X. ; 37:12, s. 1329-1342
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Journal article (peer-reviewed)abstract
- This paper focuses on evaluating the performance of a new impinging jet ventilation system and compares its performance with a wall displacement ventilation system. Experimental data for an impinging jet in a room are presented and non-dimensional expressions for the decay of maximum velocity over the floor are derived. In addition, the ventilation efficiency, local mean age of air and other characteristic parameters were experimentally and numerically obtained for a mock-up classroom ventilated with the two systems. The internal heat loads from 25 person-simulators and lighting were used in the measurements and simulations to provide a severe test for the two types of ventilation systems. In addition to a large number of experimental data CFD simulations were used to study certain parameters in more detail. The results presented here are part of a larger research programme to develop alternative and efficient systems for room ventilation.
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| 4. |
- Larsson, Ulf, 1966-, et al.
(author)
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Experimental investigation of downdraught from well-insulated windows
- 2002
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In: Building and Environment. - 0360-1323 .- 1873-684X. ; 37:11, s. 1073-1082
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Journal article (peer-reviewed)abstract
- Since the climate in the Nordic countries is cold for several months a year, windows are crucial in building envelopes. The current trend to reduce heat losses by building components has resulted in many modifications to window design in order to improve thermal performance and the indoor climate. Improvements in window construction have resulted in a higher surface temperature on the inner pane and considerably lower downdraught, which in turn has created an opportunity for the unconventional design of the heating and ventilation systems. The impetus for this paper is to experimentally investigate the effect of thermal performance, window bay and displacement ventilation on the downdraught. The measurements show that the use of well-insulated windows, besides lowering energy consumption, gives rise to a higher quality of indoor climate. The results show a considerably reduced velocity and turbulent intensity by employing a well-insulated window instead of a conventional one. The influence of the window bay on the downdraught is also shown in the paper. © 2002 Elsevier Science Ltd. All rights reserved.
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| 5. |
- Mundt, Elisabeth, 1946-
(author)
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Non-buoyant pollutant sources and particles in displacement ventilation
- 2001
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In: Building and Environment. - 0360-1323 .- 1873-684X. ; 36:7, s. 829-836
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Journal article (peer-reviewed)abstract
- Particle transportation and ventilation efficiency, with non-buoyant pollutant sources, in a displacement-ventilated room were evaluated. A resuspension of floor deposited particles caused by the influence of the supply air or people moving around may increase the number of particles in the convection flows. Particle concentrations at different positions under steady state and transient conditions were measured. The results indicate that there seem to be little risk of resuspension of particles, in the measured size interval, by the influence of the supply air. With a forced resuspension the particle concentrations in the convection flows differ from the concentration outside the convection flow. The contaminant removal effectiveness was much dependent on the position of the pollutant sources.
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| 6. |
- Rolfsman, Björn
(author)
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CO2 emission consequences of energy measures in buildings
- 2002
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In: Building and Environment. - 0360-1323 .- 1873-684X. ; 37:12, s. 1421-1430
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Journal article (peer-reviewed)abstract
- This paper studies the way in which CO2 emission levels are affected by different measures to reduce energy consumption in a building. A case study is presented which deals with a residential building in Navestad, a suburb of the Swedish city Norrköping. The building is supplied with district heating primarily delivered from a combined heat and power (CHP) plant. Three types of energy measures are studied: extra insulation, new types of window and the introduction of a heat pump. The first perspective is the city of Norrköping, with the system boundary encompassing the residential building and the CHP plants. A second worst case scenario is then presented: a Nordic perspective in which electricity produced in coal condensing power plants is assumed to cover the marginal electricity production. With the former perspective, the measures extra insulation and new windows reduce the CO2 emissions, and with the latter both measures increase the CO2 emissions. The measures extra insulation and new windows are ranked, with respect to cost for the first perspective, using a cost reduction curve for CO2 emissions. In the paper, costs from the ExternE research project are also used. © 2002 Elsevier Science Ltd. All rights reserved.
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| 7. |
- Aarts, Mariëlle P.J., et al.
(author)
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Performance of personally worn dosimeters to study non-image forming effects of light : Assessment methods
- 2017
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In: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 117, s. 60-72
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Journal article (peer-reviewed)abstract
- When determining the effects of light on human beings, it is essential to correctly measure the effects, and to correctly measure the adequate properties of light. Therefore, it is important to know what is being measured and know the quality of the measurement devices. This paper describes simple methods for identifying three quality indices; the directional response index, the linearity index and the temperature index. These indices are also checked for several commonly used portable light measurement devices. The results stresses what was already assumed, the quality and the outcome of these devices under different circumstances were very different. Also, the location were these devices are normally worn has an impact on the results. The deviation range between worn vertically at eye level and the wrist is between 11% (outdoor) to 27% (indoor). The smallest deviation, both in indoor and outdoor, was found when the device was placed on the sides of the eye (7%).
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| 8. |
- Abdul Hamid, Akram, et al.
(author)
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Hygrothermal assessment of internally added thermal insulation on external brick walls in Swedish multifamily buildings
- 2017
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In: Building and Environment. - : Elsevier BV. - 0360-1323. ; 123, s. 351-362
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Journal article (peer-reviewed)abstract
- Proper and efficient renovation requires understanding the behavior of existing buildings and of different building materials. Analyzing hygrothermal measurements in two case studies, one with and the other without an internally added thermal insulation system, enabled us to identify factors of critical importance for further assessment through simulations, and to validate a hygrothermal simulation model of a solid brick masonry wall, a model used then to assess internally added thermal insulation systems of different types. A mold resistance design (MRD) model shows that, in connection with all internally added thermal insulation systems, the risk of mold growth is appreciable when brought on by solar driven vapor from the exterior. This, if biological material is present in either of two critical areas, those of the boundary between the thermal insulation and either 1) the existing masonry wall, or 2) the exterior surface of an internally added vapor barrier. Furthermore, assessments of corrosion risks are conducted for two critical placements of the bed-joint reinforcement. At a depth of 30 mm from the exterior surface, the corrosion risk was found to be less with use of capillary-active vapor-open systems than when no thermal insulation was employed, other systems increase the corrosion risk. At a depth of 90 mm, all thermal insulation systems increase the corrosion risk. Excluding precipitation uptake eliminates all risks, showing that this is the most crucial factor. Solutions that limit this uptake or increase the drying-out rate should thus be considered beneficial.
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| 9. |
- af Klintberg, Tord, 1951-, et al.
(author)
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Air Gap Method : Dependence of water removal on RH in room and height of floor air gap
- 2012
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In: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 56, s. 1-7
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Journal article (peer-reviewed)abstract
- This study is performed in combined floor and wall constructions with air gaps within and with a heating cable in the vertical air gap. All surfaces of the air gap are covered with polystyrene plastic to avoid leakage into the construction. Wet gypsum boards that are weighed at start and end of experiment are used to measure the dry out process.Three different heights of the floor air gap, 25 mm, 15 mm and 5 mm are investigated. The influences of the RH in the surrounding room and of the wetness of the gypsum boards are also investigated.It is shown that the height of the floor air gap has a great impact on the rate of drying. The optimal height is less than 25 mm and somewhere between 15 and 5 mm.
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| 10. |
- Albuquerque, Daniel P., et al.
(author)
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Experimental and numerical investigation of pumping ventilation on the leeward side of a cubic building
- 2020
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In: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 179
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Journal article (peer-reviewed)abstract
- Unstable interaction between shear layers that form in the wake of an isolated building exposed to wind can drive natural pumping ventilation in windward and leeward facing rooms with two or more horizontally separated openings. This paper presents an experimental and numerical study of pumping ventilation in a three-story cubic building with two leeward openings in its middle floor. Reduced-scaled measurements were performed in the University of Gävle atmospheric-boundary-layer wind tunnel. The ventilation mechanism was investigated using smoke visualization, hot wire anemometry and particle image velocimetry. Effective ventilation rates were obtained using a tracer gas decay method. Experimental results confirmed that pumping ventilation is a 3D oscillatory unstable phenomenon with periodic behavior over several oscillation cycles. Measured flowrates show a linear relation between the effective ventilation rate and window separation. The numerical simulations used two turbulence modeling approaches: unsteady Reynolds-averaged Navier-Stokes (URANS) and large eddy simulation (LES). Both URANS and LES could predict vortex shedding frequency with an error below 5%. LES showed a good agreement with the measured ventilation rates, with an error below 10%, while URANS underestimated ventilation rates by at least 40%. The ventilation efficiency, obtained by LES, ranged between 0.60 and 0.75 (for the case with larger window separation). The results show that LES may be a suitable simulation approach for pumping ventilation. In contrast, URANS cannot simulate pumping ventilation.
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