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Lindbergh, L., Olofsson, T., Vesterberg, J., Andersson, S. & Wilson, T. (2018). Reflections on sustainable Ålidhem: a case study in Swedish municipal public housing refurbishment. Property Management, 36(2), 203-220
Open this publication in new window or tab >>Reflections on sustainable Ålidhem: a case study in Swedish municipal public housing refurbishment
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2018 (English)In: Property Management, ISSN 0263-7472, E-ISSN 1758-731X, Vol. 36, no 2, p. 203-220Article in journal (Refereed) Published
Abstract [en]

Purpose: This work is initiated under the premise that reliable evaluation methods are necessary to ensure investments in energy conservation, and the purpose of this paper is to contribute to that literature. It describes some pilot changes and their impact in an actual field study oriented toward upgrading municipal public housing (MPH) units.

Design/methodology/approach: The research for this paper was connected to an MPH refurbishment project situated in northern Sweden. The overall energy efficiency goal within the project was a 40-50 percent reduction in the supplied energy for central electricity, domestic hot water and space heating. In order to evaluate if these goals were feasible, a measurement system was installed in a pilot building and in a neighboring building used as a reference. The evaluation was conducted by comparing the post-retrofit performance of the pilot building with the performance of the reference building when it was kept in its initial state (a comparison possible because both buildings had initial similarities).

Findings: Impacts could be quantified insofar as a reference (control) building in the same environment was sustained for comparison purposes. A 43 percent improvement was observed in energy utilization in the pilot building compared to its reference companion (99.8 vs 174.5 kWh/m2 per year). When the approach described herein was applied to new construction, the present goal of 65 kWh/m2 was approached as measured by Swedish standards.

Practical implications: Results should be of interest to academics in the housing field, professionals involved in refurbishment and residents themselves, renting MPH flats.

Originality/value: This study is unique in the following ways: first, it really was a field experiment with a control, thus it did not have any exogenous interference in interpreting results. To the best of our knowledge, this is the first study of its kind. The second interesting characteristic was that results were subsequently used in the refurbishment of other buildings in the complex and in the construction of others. The major value of the paper may be associated with its timing. It comes at a time when the Kyoto agreement has raised concerns about sustainability, but also at a time when many buildings are facing a need for refurbishment.

Place, publisher, year, edition, pages
Emerald Group Publishing Limited, 2018
Keywords
Refurbishment, Energy Savings, Systematic Approach, Municipal Public Housing, Sweden
National Category
Business Administration Civil Engineering
Research subject
Business Studies
Identifiers
urn:nbn:se:umu:diva-138657 (URN)10.1108/PM-04-2016-0017 (DOI)000428653800006 ()
Available from: 2017-08-26 Created: 2017-08-26 Last updated: 2018-06-09Bibliographically approved
Vesterberg, J. & Andersson, S. (2017). Achieved Energy and Climate Goals in Project Ålidhem: An Evaluation of a Refurbishment of 21 Swedish multifamily Buildings. Paper presented at 11th Nordic Symposium on Building Physics, NSB2017, 11-14 June 2017, Trondheim, Norway. Energy Procedia, 132, 51-56
Open this publication in new window or tab >>Achieved Energy and Climate Goals in Project Ålidhem: An Evaluation of a Refurbishment of 21 Swedish multifamily Buildings
2017 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 132, p. 51-56Article in journal (Refereed) Published
Abstract [en]

In Umeå, situated in the north part of Sweden, the largest refurbishment project undertaken by the public housing company in Umeå was completed in 2014. The project had ambitious goals to decrease the bought energy use for domestic hot water, building electricity and space heating, by 50 %. In order to achieve this, a variety of energy conservation measures were implemented in 21 multifamily buildings during the four-year project. This paper describes the used evaluation approaches and the achieved energy and climate goals. Finally, it offers some reflections that are hoped to be useful in similar projects. 

Keywords
Building refurbishment, Measurements, Energy performance
National Category
Environmental Analysis and Construction Information Technology
Identifiers
urn:nbn:se:umu:diva-136009 (URN)10.1016/j.egypro.2017.09.630 (DOI)000426435500009 ()
Conference
11th Nordic Symposium on Building Physics, NSB2017, 11-14 June 2017, Trondheim, Norway
Note

Special issue: 11th Nordic Symposium on Building Physics, NSB2017, 11-14 June 2017, Trondheim, Norway

Available from: 2017-06-12 Created: 2017-06-12 Last updated: 2018-06-25Bibliographically approved
Mejtoft, T. & Vesterberg, J. (2017). Integration av generiska kunskaper inom ingenjörsutbildning. In: Universitetspedagogiska konferensen 2017: . Paper presented at Universitetspedagogiska konferensen 2017, Umeå universitet, 24-25 oktober, 2017.
Open this publication in new window or tab >>Integration av generiska kunskaper inom ingenjörsutbildning
2017 (Swedish)In: Universitetspedagogiska konferensen 2017, 2017Conference paper, Oral presentation only (Other academic)
National Category
Didactics
Identifiers
urn:nbn:se:umu:diva-142324 (URN)
Conference
Universitetspedagogiska konferensen 2017, Umeå universitet, 24-25 oktober, 2017
Available from: 2017-11-27 Created: 2017-11-27 Last updated: 2019-06-19Bibliographically approved
Mejtoft, T. & Vesterberg, J. (2017). Integration of generic skills in engineering education: Increased student engagement using a CDIO approach. In: R. Brennan, K. Edström, R. Hugo, J. Roslöf, R. Songer & D. Spooner (Ed.), The 13th International CDIO Conference: Proceedings – Full Papers. Paper presented at The 13th International CDIO Conference, Calgary, Canada, June 18-22, 2017 (pp. 386-395). Calgary AB, Canada: University of Calgary
Open this publication in new window or tab >>Integration of generic skills in engineering education: Increased student engagement using a CDIO approach
2017 (English)In: The 13th International CDIO Conference: Proceedings – Full Papers / [ed] R. Brennan, K. Edström, R. Hugo, J. Roslöf, R. Songer & D. Spooner, Calgary AB, Canada: University of Calgary, 2017, p. 386-395Conference paper, Published paper (Refereed)
Abstract [en]

To be able to successfully pursue a future career within engineering, students need to acquire not only disciplinary knowledge but also generic skills to become professionals. The CDIO model provides a foundation of generic skills that can be expected by the students’ future employers. This paper presents pros and cons when integrating generic skills in disciplinary projects and is based on surveys and interviews with students and teachers on two integrated courses, Project management and Interactivity in smart environments, on an integrated five-year Master of Science program at Umeå University.

The results show that integrating two courses to give disciplinary meaning to projects make the students maintain their motivation during the course in Project management. In addition, the integration of the courses led to more time for the students for the actual project work. Lastly, both students and teachers also had the possibility to provide a better formal project structure on the disciplinary course. However, the results also show that the confusion among the students increased due to different requirements in each course. Thus, a high level of communication and a holistic view among the involved teachers is desirable to improve the overall success in course integration.

Place, publisher, year, edition, pages
Calgary AB, Canada: University of Calgary, 2017
Series
Proceedings of the International CDIO Conference, ISSN 2002-1593, E-ISSN 1796-9964
Keywords
Project management, Case-based, Project work, Standards 1 2 3 5 8 11
National Category
Didactics
Identifiers
urn:nbn:se:umu:diva-136637 (URN)978-0-88953-399-8 (ISBN)
Conference
The 13th International CDIO Conference, Calgary, Canada, June 18-22, 2017
Available from: 2017-06-28 Created: 2017-06-28 Last updated: 2018-06-09Bibliographically approved
Lindbergh, L., Olofsson, T., Vesterberg, J. & Wilson, T. L. (2017). Project Ålidhem: a case study of a sustainable Swedish municipal public housing installation. Energy Procedia, 121, 11-17
Open this publication in new window or tab >>Project Ålidhem: a case study of a sustainable Swedish municipal public housing installation
2017 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 121, p. 11-17Article in journal (Refereed) Published
Abstract [en]

A refurbishment project conducted within a municipal public housing complex is described and discussed through Project Ålidhem in northern Sweden. The overall energy efficiency goal within the project was a 40-50% reduction in the supplied energy for domestic hot water, building electricity and space heating. In the pilot study, a 43% improvement was observed. This paper focuses on the performance of four buildings constructed under a Delegation for Sustainable Cities program that specified an energy efficiency goal of 65 kWh/m2. This goal was approached, but not attained. Observations of utilization in four free-standing buildings were 68.3, 76.8, 87.2 and 87.6 kWh/m2 per year respectively, which are described and discussed herein.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2017
Keywords
Energy efficiency, refurbishment, project Ålidhem, Sweden
National Category
Economics and Business
Identifiers
urn:nbn:se:umu:diva-139779 (URN)10.1016/j.egypro.2017.08.002 (DOI)000426789900002 ()
Available from: 2017-09-22 Created: 2017-09-22 Last updated: 2018-06-09Bibliographically approved
Vesterberg, J., Andersson, S. & Olofsson, T. (2016). A single-variate building energy signature approach for periods with substantial solar gain. Energy and Buildings, 122, 185-191
Open this publication in new window or tab >>A single-variate building energy signature approach for periods with substantial solar gain
2016 (English)In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 122, p. 185-191Article in journal (Refereed) Published
Abstract [en]

The use of regression analysis for the identification of building performance parameters based on measurements is often difficult due to collinearity between the outdoor temperature and the global solar radiation (S). This study proposes a method to overcome this issue. The proposed method is based on using the seasonal symmetry of S to pair data from time-periods equidistant from the winter solstice. In addition, a method to utilize synthetic data to fine-tune the paired-data approach is presented. To evaluate the paired-data approach, two years data from a multifamily building in Umeå was used to estimate the heat loss factor (air-to-air transmission including air leakage). The results were compared with results obtained when S was very low (S ≈ 0). It was found that, the fine-tuned paired-data approach resulted in a modest deviation in the heat loss factor with an average absolute deviation of 4.0%. The small deviation indicates that the paired-data approach can extend the use of single-variate regression models for accurate identification of heat loss factors to situations where the solar gain is substantial. The paired-data approach was also used to calibrate a commercial energy building simulation tool. 

Keywords
Regression, Energy signature models, IDA-ICE, Building, Solar gain
National Category
Building Technologies
Identifiers
urn:nbn:se:umu:diva-117244 (URN)10.1016/j.enbuild.2016.04.040 (DOI)000376833300018 ()
External cooperation:
Available from: 2016-02-24 Created: 2016-02-24 Last updated: 2018-06-07Bibliographically approved
Vesterberg, J., Andersson, S. & Olofsson, T. (2016). Calibration of low-rise multifamily residential simulation models using regressed estimations of transmission losses. Journal of Building Performance Simulation, Taylor & Francis, 9(3), 304-315
Open this publication in new window or tab >>Calibration of low-rise multifamily residential simulation models using regressed estimations of transmission losses
2016 (English)In: Journal of Building Performance Simulation, Taylor & Francis, ISSN 1940-1493, E-ISSN 1940-1507, Vol. 9, no 3, p. 304-315Article in journal (Refereed) Published
Abstract [en]

In this study, we evaluated a proposed calibration approach for whole-building energy simulation models. This approach was based on a regression analysis of measured data collected during a time period when the global solar radiation was the lowest. The proposed approach was compared with a more conventional calibration approach with different degrees of complexity, starting from design stage assumptions, through audits, and lastly by refining the model with detailed measurements and numerical calculations. The evaluation was performed using measured data from two multifamily buildings located in Umeå, Sweden, and the IDA ICE 4.61 simulation software. The best agreement between simulated and measured data was obtained with the proposed calibration approach. The monthly normalized mean bias error and the coefficient of variation was less than 5.0% and 6.0% respectively. For the conventional calibration approach, detailed measurements and time-consuming numerical calculations were required to reach similar results. 

Keywords
IDA ICE, calibrated simulation, regression, BES models
National Category
Physical Sciences
Identifiers
urn:nbn:se:umu:diva-106815 (URN)10.1080/19401493.2015.1067257 (DOI)000374992500005 ()2-s2.0-84938651135 (Scopus ID)
Available from: 2015-08-07 Created: 2015-08-07 Last updated: 2018-06-07Bibliographically approved
Vesterberg, J. (2016). Improved building energy simulations and verifications by regression. (Doctoral dissertation). Umeå: Umeå universitet
Open this publication in new window or tab >>Improved building energy simulations and verifications by regression
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

It is common with significant differences between calculated and actual energy use in the building sector. These calculations are often performed with whole building energy simulation (BES) programs. In this process the analyst must make several assumptions about the studied building and its users. These calculations are often verified with measured data through the EUI benchmark indicator which is calculated by normalizing the annual energy use (from the grid) with the floor area. Due to the highly aggregated nature of the EUI indicator it is problematic to use this indicator to deduce erroneous assumptions in the calculations. Consequently, the learning process is often troublesome.

Against this background, the main aim of this thesis has been to develop methods that can provide feedback (key building performance parameters) from measured data which can be used to increase simulation accuracy and verify building performance. For the latter, regression models have been widely used in the past for verifying energy use. This thesis has the focus on the use of regression analysis for accurate parameter identification to be used to increase the agreement between BES predictions and actual outcome. For this, a BES calibration method based on input from regressed parameters has been developed which has shown promising features in terms of accurate predictions and user friendliness. The calibration method is based on input from regressed estimations of air-to-air-transmission losses, including air leakage (heat loss factor) and ground heat loss. Since it is known that bias models still can give accurate predictions, these parameters have been evaluated in terms of robustness and agreement with independent calculations. In addition, a method has been developed to suppress the bias introduced in the regression due to solar gain. Finally, the importance of calibrated simulations was investigated.

The regressed parameters were found to be robust with yearly variations in the heat loss factor of less than 2%. The regressed estimates of ground heat loss were also in good agreement with independent calculations. The robustness of the heat loss factor based on data from periods of substantial solar gain was also found to be high, with an average absolute deviation of 4.0%. The benefit with calibrated models was mainly found to be increased accuracy in predictions and parameters in absolute terms. With increased access to measured data and the promising results in this thesis it is believed that the presented regression models will have their place in future energy quantification methods for accessing energy performance of buildings. 

Abstract [sv]

Det är vanligt med betydande skillnader mellan beräknad och verklig energi användning inom byggnadssektorn. Dessa beräkningar utförs ofta med hjälp av byggnads energi simulerings (BES) program där användaren måste göra ett flertal antaganden om den aktuella byggnaden och dess brukare. Det beräknade resultatet kontrolleras ofta i ett senare skede mot byggnadens faktiska behov av energi från nätet. I denna kontroll är det dock svårt att särskilja den energimängd som byggnaden behöver och den del som är kopplad till brukaren. Detta gör att lärdomarna som kan dras i denna verifieringsprocess ofta blir begränsade.

Mot denna bakgrund, har det huvudsakliga syftet med denna avhandling varit att utveckla metoder som kan användas för att extrahera information om byggnadens prestanda från mätdata. De extraherade parametrarna skall kunna användas för att öka noggrannheten i prediktioner från BES modeller och för att verifiera byggnaders prestanda. Regression analys har ofta använts i det senare fallet i avseendet att verifiera energi användning. Denna avhandling fokuserar på att utveckla regressionsmodeller som ger en hög noggrannhet i modellens parametrar som möjliggör att de bl.a. kan användas för att kalibrera BES modeller och på så sätt minska den vanligt förekommande diskrepans mellan simulerat och faktiskt utfall. En BES kalibrerings metodik har utvecklats baserat på skattning av transmissions förluster ovan mark, inklusive luftläckage (värmeförlust koefficient) samt värmeförlust till mark (G) med hjälp av regressionsanalys. Denna kalibrerings metodik uppvisar lovande egenskaper i form av noggranna prediktioner och användarvänlighet. Goda prediktioner är dock ingen garanti för att modellens ingående parametrar är fysikaliskt rimliga. Därför har regressionsmodellernas parametrar utvärderats i termer av robusthet och överensstämmelse med oberoende beräkningar. Dessutom har en metod utvecklats för att minimerar solens inverkan på regressionsskattningarna. Slutligen har vikten av kalibrerade simuleringar undersökts.

Parametrarna i de framtagna regressionsmodellerna visade sig vara robusta, med årliga variationer i värmeförlust koefficient mindre än 2%. Ytterligare visade sig G var i god överensstämmelse med oberoende beräkningar. Robustheten i värmeförlustfaktorn baserad på data från perioder av betydande solstrålning konstaterades också att vara hög, med en genomsnittlig absolut avvikelse på 4.0%. Fördelen med kalibrerade modeller visade sig främst vara en ökad noggrannhet i prediktioner och modell parametrar i absoluta tal. Med ökad tillgång till mätdata och lovande resultat i denna avhandling är det författarens övertygelse att de presenterade regressionsmodellerna kommer att ha sin plats i framtida bedömnings metoder av byggnaders energiprestanda.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2016. p. 51
Keywords
Calibrated simulations, Energy signature, Regression, BES, IDA ICE, Multifamily buildings, EUI
National Category
Energy Engineering
Identifiers
urn:nbn:se:umu:diva-117248 (URN)978-91-7601-430-1 (ISBN)
Public defence
2016-03-17, N450, Naturvetarhuset, Umeå universitet, Umeå, 13:00 (English)
Opponent
Supervisors
Available from: 2016-02-25 Created: 2016-02-24 Last updated: 2018-06-07Bibliographically approved
Vesterberg, J. (2016). Utilizing a regression approach for troubleshooting energy performance of Swedish buildings. In: CLIMA 2016 - proceedings of the 12th REHVA World Congress: . Paper presented at CLIMA 2016 - 12th REHVA World Congress, 22-25 May 2016, Aalborg, Denmark. , 8
Open this publication in new window or tab >>Utilizing a regression approach for troubleshooting energy performance of Swedish buildings
2016 (English)In: CLIMA 2016 - proceedings of the 12th REHVA World Congress, 2016, Vol. 8Conference paper, Published paper (Refereed)
Abstract [en]

The follow-up of calculated and actual energy performance for new buildings is important to enable a learning process. Performance verification is however not a trivial task since the traditional energy use intensity indicator (EUI) can display large variations even for buildings with similar design and HVAC systems. Hence, there exists a risk for confusion between building owners and developers when predicted and actual outcome are compared using only this indicator. In this paper, simple methods, based on area normalization and regression analysis are investigated for interpretation of wide discrepancies in measured EUIs within four similar, newly built multifamily buildings in Umeå, Sweden. It was found that the discrepancies in specific annual energy demand were dependent on the area used for normalization but did not fully explain the variation in the EUIs. The utilization of linear regression for identification and comparison of the buildings heat-loss factor, (ventilation and transmission), and effective solar aperture provided further insights. The regression analysis indicated that the differences in EUIs were due to a combination of chosen area for normalization and solar gain and not the consequence of variations in actual U-values and HVAC systems. Due to the regression methods robustness against influence from the users, it was concluded that the method works well as a complement to the EUI indicator since it provides insights of the buildings thermal performance. This is often of interest to verify for the developer and the property owner since the thermal performance can be controlled in the construction process.

Keywords
Energy use intensity, EUI, Regression, Heat loss factor, Shape factor
National Category
Civil Engineering
Identifiers
urn:nbn:se:umu:diva-92398 (URN)87-91606-33-0 (vol 8) (ISBN)87-91606-36-5 (set) (ISBN)
Conference
CLIMA 2016 - 12th REHVA World Congress, 22-25 May 2016, Aalborg, Denmark
Note

Originally published in manuscript form.

Available from: 2014-08-26 Created: 2014-08-26 Last updated: 2018-06-07Bibliographically approved
Vesterberg, J. (2014). A regression approach for assessment of building energy performance. (Licentiate dissertation). Umeå: Umeå universitet
Open this publication in new window or tab >>A regression approach for assessment of building energy performance
2014 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Reliable evaluation methods is needed to ensure that investments in energy conservation measures (ECMs) and the construction of new energy efficient buildings lives up to the promised and expected performance.

This thesis presents and evaluates a regression method for estimation of influential building parameters: transmission losses above ground (including air leakage), ground heat loss, and overall heat loss coefficient.

The analysis is conducted with separately metered electricity, heating and weather data using linear regression models based on the simplified steady-state power balance for a whole building.

The evaluation consists of analyzing the robustness of the extracted parameters, their suitability to be used as input values to building energy simulations (BES) tools. In addition, differences between uncalibrated and calibrated BES models are analyzed when they are used to calculate energy savings. Finally the suitability of using a buildings overall heat loss coefficient as a performance verification tool is studied.

The presented regression method exhibits high robustness and good agreement with theory. Knowledge of these parameters also proved beneficial in BES calibration procedures as well as in performance verifications. Thus, the presented method shows promising features for reliable energy performance assessments of buildings.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2014. p. 25
Keywords
building energy simulation, measurements, regression, calibration parameters
National Category
Engineering and Technology
Identifiers
urn:nbn:se:umu:diva-92465 (URN)978-91-7601-125-6 (ISBN)
Presentation
2014-09-17, A302, Håken Gullessons väg 20, Umeå, 10:00 (English)
Opponent
Supervisors
Available from: 2014-09-26 Created: 2014-08-26 Last updated: 2018-06-07Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7332-1521

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