| 1. |
- Abugabbara, Marwan, et al.
(författare)
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Validation of TEKNOsim 6 According to CIBSE TM33
- 2018
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Ingår i: Cold Climate HVAC 2018 : Sustainable Buildings in Cold Climates - Sustainable Buildings in Cold Climates. - Cham : Springer International Publishing. - 2352-2542 .- 2352-2534. - 9783030006617 - 9783030006624 ; , s. 665-676
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Bokkapitel (refereegranskat)abstract
- TEKNOsim is a simple and user-friendly program for analyzing thermal indoor climate and performing annual hourly simulations. The program was originally developed to calculate heating and cooling demands, and indoor climate conditions of a single zone building for peak winter and summer design days. However, TEKNOsim version 6 has been revised to incorporate several new features including annual energy and multi-zone simulations. These features greatly enhance the functionality and the ability of the program. Their implementation in TEKNOsim 6, however, entails a validation procedure to test the accuracy of the new algorithms. This paper presents preliminary results of the ongoing testing and validation of TEKNOsim 6 according to CIBSE TM33 tests for software accreditation and verification. The test results indicate that the new database libraries implemented in TEKNOsim 6 can be easily customized to precisely represent the actual building conditions. The results also show that the program can accurately calculate the total steady-state heat losses for all test cases of CIBSE TM33. The peak cooling loads calculated by TEKNOsim 6 are also in good agreement with CIBSE TM33 for most test cases. Some discrepancies are however observed between TEKNOsim 6 and CIBSE TM33, especially for test cases involving certain building elements. Nevertheless, TEKNOsim 6 is shown to be a fast and reliable program for performing early-design stage simulations.
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| 2. |
- Arghand, Taha, 1982, et al.
(författare)
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Dynamic Thermal Performance and Controllability of Fan Coil Systems
- 2018
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Ingår i: Cold Climate HVAC 2018: Springer Proceedings in Energy. - Cham : Springer International Publishing. - 2352-2542 .- 2352-2534. - 9783030006617 ; , s. 351-361
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Konferensbidrag (refereegranskat)abstract
- In order to characterize and control a system properly, it is inevitably necessary to understand and define the interactions between various design parameters and the controllability of the system. This study experimentally investigates effects of three design parameters, including supply water temperature, fan speed, and room heat load, on the dynamic response of a fan coil system. The experiments have been performed in a mock-up of an office room equipped with a fan coil unit (FCU). A direct ground cooling system has been used to supply the FCU with high-temperature chilled water ranging between 15 and 23 °C. The dynamic response of the system to step changes in the design parameters has been studied using room operative temperature as an indicator. The results of this study indicate that the system behaves as a first-order system without a time delay. The results also suggest that the time constant and the characteristic of the dynamic response of the fan coil system are not affected by the initial room temperature. Among the design parameters, fan speed is observed to have the most significant effect on the dynamic response of the system. Supply water temperature and room heat load are both found to have insignificant effects on the dynamic response characteristics of the system.
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| 3. |
- Bahrami, Soheila, et al.
(författare)
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Communicating the Acoustic Performance of Innovative HVAC Solutions
- 2018
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Ingår i: Springer Proceedings in Energy : Cold Climate HVAC 2018 - Cold Climate HVAC 2018. - 9783030006617 - 9783030006624 ; , s. 1085-1085
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Konferensbidrag (refereegranskat)abstract
- Recent years have seen considerable advancements in Demand Controlled Ventilation (DCV) systems aimed to improved energy efficiency and indoor environmental quality in buildings. A significant aspect of DCV systems is their impact on the acoustic comfort in buildings. This study is part of the Urban Tranquility project with a focus on innovative DCV systems. The objective is to add more understanding about communicating the acoustic performance of innovative HVAC solutions during the diffusion phase of the innovation. The research method is a case study on an innovative DCV system that shows how the acoustic performance of the system is communicated with the stakeholders and in what ways the applied methods can be improved. Data collection has been performed through reviewing relevant technical documents and software as well as semi-structured interviews with different stakeholders. The data has been analyzed with reference to three types of knowledge about an innovation. The results indicate that the acoustic performance of this new DCV system has not been effectively communicated due to inconsistent methods of expressing the information. This has revealed the need for developing a systematic method of communicating the acoustic information on DCV systems with the key stakeholders.
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| 4. |
- Berggren, Björn, et al.
(författare)
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A Net ZEB case study – Experiences from freezing in ventilation heat exchanger and measured energy performance
- 2019
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Ingår i: Cold Climate HVAC 2018. CCC 2018. - Cham : Springer International Publishing. - 9783030006617 - 9783030006624 ; , s. 613-622
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Konferensbidrag (refereegranskat)abstract
- Net Zero Energy Buildings constitute one measure to reduce energy use and increase use of energy from renewable sources. Hence, it is important share knowledge and experiences from completed projects. This case study show that it is possible to build Net Zero Energy Buildings with existing techniques. However, a common strategy to prevent or limit the build-up of ice and frost in ventilation heat exchangers, Supply fan shut off, were not suitable this project, since it is air tight buildings. After occurring problems in the first winter, ventilation pre-heater were installed to prevent the build-up of ice and frost. Thanks to placement of temperature sensor after the pre-heater, the increased energy use for pre-heater may be expected to be low, roughly 1 kWh/m2a.
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| 5. |
- Berggren, Björn, et al.
(författare)
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Normalisation of Measured Energy Use in Buildings — Need for a Review of the Swedish Regulations
- 2019
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Ingår i: Cold Climate HVAC 2018. CCC 2018. - Cham : Springer International Publishing. - 9783030006617 - 9783030006624 ; , s. 995-995
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Konferensbidrag (refereegranskat)abstract
- Normalisation of measured energy use in buildings is important in order to verify their performance in user phase. Two methods for normalisation have been presented in Sweden, static and dynamic normalisation. The static normalisation considers deviating hot water use, indoor temperature, internal loads and external climate. The dynamic normalisation is based on repeated simulation, meaning that the initial simulation, carried out during the design phase, is repeated with updated conditions regarding actual use of the building and exterior climate. The ratio between the first and second simulation is used as a factor for normalisation. A pre-study has been initiated in Sweden to enable further development of the two methods. This paper present the two methods, the initiated pre-study, and some early findings. The early findings show that there is need for further development of the methods presented.
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| 6. |
- Dahlblom, Mats, et al.
(författare)
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Vertical temperature gradients in apartments with hydronic radiator heating
- 2019
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Ingår i: Cold Climate HVAC 2018 : Sustainable Buildings in Cold Climates - Sustainable Buildings in Cold Climates. - Cham : Springer International Publishing. - 9783030006617 - 9783030006624 ; , s. 575-585
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Konferensbidrag (refereegranskat)abstract
- A vertical temperature stratification normally exists in rooms during the heat-ing season in cold climates. An expression of the gradient in apartments heated by hydronic radiator heating systems with exhaust ventilation has ear-lier been developed assuming a dependency of the outdoor temperature. The expression was used by a public real estate owner when re-calculating meas-ured indoor temperature at 2.1 m above floor to 1.2 m above floor represent-ing the occupancy zone and used for individual metering and billing of space heating cost. To validate the suggested expression temperature measurements have been made at four heights in living rooms in apartments built in the 70’s. The heights includes 0.0, 0.1, 1.1 and 1.7 m above floor. The theoreti-cal expression has been compared to the full-scale measurements and in general the expression overestimates the vertical temperature gradient. The measured gradients are generally very low. The thermal comfort in the aspect of vertical temperature gradient is good for the studied period.
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| 7. |
- Danielski, Itai, 1973-, et al.
(författare)
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Atrium in residential buildings – a design to enhance social interaction in urban areas in Nordic climates
- 2018
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Ingår i: Cold Climate HVAC 2018. - Cham : Springer. - 9783030006617 - 9783030006624 ; , s. 773-789
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Bokkapitel (refereegranskat)abstract
- The design concept of conditioned atria receive growing popularity in both commercial and service buildings all over the world, but still not common in the residential sector. This study used a psychological framework to examine if building design with enclosed heated atria in apartment buildings can enhance sense of community and social interactions in Nordic climates. A qualitative study was conducted to understand the perception of residents living in apartment buildings with heated atrium. One of the few examples in Sweden. This was compared to the experience of residents in a “traditional” apartment building without an atrium. The questionnaire was comprised of six parts: (i) socio-demographic aspects; (ii) information about the apartment; (iii) social activities within the building; (iv) social interaction with neighbours; (v) information about principles in life; and (vi) sense of community linked to their homes.The results showed significant social differences between the residents of the atrium and “traditional” buildings, which could not be explained solely by differences in preferences and principles in life. A large proportion of the social differences between the buildings could be explained by the building design, as the common and semi-private areas within the atrium building provide opportunities to establish social interactions. The residents in the atrium building was found to have greater sense of community and higher frequency of interactions, which are both parts of social sustainability.
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| 8. |
- Dodoo, Ambrose, 1979-, et al.
(författare)
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Impacts of Common Simulation Assumptions in Sweden on Modelled Energy Balance of a Multi-family Building.
- 2019
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Ingår i: Cold Climate HVAC 2018. - Cham : Springer. - 9783030006617 - 9783030006624 ; , s. 689-699
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Konferensbidrag (refereegranskat)abstract
- Here, we explore key input parameters and common assumptions for energy balance analysis of residential buildings in Sweden and assess their impacts on simulated energy demand of a building. Our analysis is based on dynamic hour-by-hour energy balance modelling of a typical Swedish multi-storey residential building constructed in 1972. The simulation input parameters studied are related to microclimate, building envelope, occupancy behaviour, ventilation, electric and persons heat gains. The results show that assumed indoor temperature set points, internal heat gains and efficiency of ventilation heat recovery systems have significant impact on the simulated energy demand. For microclimate parameters, the outdoor temperature, ground solar reflection and window shading gave significant variations in the simulated space heating and cooling demands. We found that input parameter values and assumptions used for building energy simulation vary significantly in the Swedish context, giving considerably different estimated annual final energy demands for the analysed building. Overall, the estimated annual final space heating demand of the building varied between 50 and 125 kWh/m2 depending on the simulation dataset used. This study suggests that site-specific parameter values may be appropriate for accurate analysis of a building’s energy performance to reduce data input uncertainties, as such factors may have a significant impact on building energy balance and energy savings of retrofit measures.
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| 9. |
- Femenias, Paula, 1966, et al.
(författare)
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Renovating the Housing Stock Built Before 1945: Exploring the Relations Between Energy Efficiency, Embodied Energy and Heritage Values
- 2018
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Ingår i: Springer Proceedings in Energy: Cold Climate HVAC 2018, Kiruna, Sweden, 12-15 March, 2018. - Cham : Springer International Publishing. - 9783030006617 - 9783030006624 ; , s. 291-301
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Konferensbidrag (refereegranskat)abstract
- Swedish multi-family buildings constructed before 1945 constitutes an important part of the national built heritage. However, the majority does not have a formal heritage protection. Part of this building stock has already been renovated, notably through earlier energy saving programmes where additional exterior insulation, new façades and windows were frequently installed with little consideration for the original architecture. Now, 40 years later, these buildings face new renovations. This provides opportunities to improve the energy efficiency, indoor climate and user comfort. At the same time, the original architectural and historical characters lost in previous renovations could be recreated. In this paper, an inter-disciplinary research team illustrates the challenges met in practice to reach a sustainable renovation based on three cases. The case buildings are so-called "Landshövdingehus”, constructed in the 1930s and owned by a public housing company. The relations between building physics, energy efficiency, embodied energy, and the effect on heritage aspects in renovation are studied. The results demonstrate the potential to reach 30% calculated energy efficiency without investing in ventilation systems. When comparing embodied energy to savings in operational energy a short payback time is achieved. However, focusing on the replacement of windows, the cases illustrate difficulties to recreate heritage values at same time as achieving an air-tight and energy efficient construction. In order to improve the results from a heritage point of view, there is a need for quality assurance of the renovation and building permit process.
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| 10. |
- Hayati, Abolfazl, et al.
(författare)
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Simulation of Ventilation Rates and Heat Losses during Airing in Large Single Zone Buildings in Cold Climates
- 2019
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Ingår i: Cold Climate HVAC 2018. - : Springer. - 9783030006617 - 9783030006624
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Konferensbidrag (refereegranskat)abstract
- Airing can be a solution to introduce extra ventilation in large single zone buildings, especially where there are large aggregations of people such as churches or atriums. In naturally ventilated domestic and ancient buildings, opening of a window or door can introduce extra fresh air and remove particles and other contaminants emitted from people and other sources such as lit candles in churches. However, the energy use might be an issue in cold climates, where airing might lead to waste of heated air, at the same time as indoor air temperatures can be uncomfortably low. In the present study, the energy loss and ventilation rate due to airing in a large single zone (church) building is investigated via IDA-ICE simulation on annual basis in cold weather conditions. The results can be used in order to prepare airing guidelines for large single zone buildings such as atriums, churches, industry halls and large sport halls. According to the results, one-hour of airing in the studied church building resulted in 40-50 % of exchanged room air and, if practiced once a week, an increase of around 1 % in heating energy.
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