| 1. |
- Dahlblom, Mats, et al.
(författare)
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Reglering av värmesystem i flerbostadshus med individuell värmemätning
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Indoor temperatures in multifamily houses are indirectly controlled by the outdoor temperature. The radiator supply temperature is a function of the outdoor temperature. This control principle cannot take into account for disturbances from people, electric appliances, airing, sun, and air leakage due to wind. A control setting with a suitable margin can avoid complaints, but may result in overheating and airing. The obvious control principle with direct control of indoor temperature has been tested with good result in 1978. The exhaust air temperature was used as a measure of the indoor temperature. LKF, Lund community housing company, has installed individual metering of heating costs using the indoor temperature in each flat. The research project aim was to use these temperature measurements and to test the control principle and compare the energy saving versus normal control and no individual metering of heating costs. The normal control has been extended with a limited proportional correction of the supply temperature. The extended control gives a more constant indoor temperature, which is appreciated by the maintenance personnel. A comparison between 2009/2010 and 2011 shows that the heating cost is larger than the control group due to higher indoor temperature caused by limited extended control, low gain and improper selection of desired indoor temperature at start up. The study has been performed with financial support from CERBOF - the Centre for Energy and Resource Efficient Construction and Facilities management.
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| 2. |
- Dahlblom, Mats, et al.
(författare)
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Variations in indoor temperature in residential apartments of different size and building category
- 2014
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Ingår i: NSB 2014 : 10th Nordic Symposium on Building Physics,15-19 June 2014 Lund, Sweden. - 9789188722539 ; , s. 830-837
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Konferensbidrag (refereegranskat)abstract
- In a case study, comprising 1177 residential apartments with 3248 rooms, temperature registrations every 15th minute in all living-rooms and bedrooms, during one year, in the system for individual metering and billing of space heating costs, were analyzed. The apartments were divided into two categories, apartment blocks from 1960th and row houses from about 1990. Apartments mean temperatures and standard deviations as a function of apartment size and category was compared. Corresponding was done on room level divided on apartment size for the two building categories. Finally, temperatures in bedrooms were compared to those in living-rooms for two objects from each category; presented in duration charts based on all single 15th minute values. The same pattern between different apartment sizes is kept for all month, though with a seasonal variation. The livingrooms are in mean warmer than bedrooms. The larger the apartments are the larger are the differences. The results provide a more nuanced picture of the temperature conditions in homes beneficial for better input data for building energy simulations.
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| 3. |
- Dahlblom, Mats, et al.
(författare)
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Vertical temperature increase in multi-storey buildings
- 2014
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Ingår i: NSB 2014 : 10th Nordic Symposium on Building Physics,15-19 June 2014 Lund, Sweden. - 9789188722539 ; , s. 814-821
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Konferensbidrag (refereegranskat)abstract
- Indoor temperature is by measurements stated to rise 0.1 – 0.2°C per storey upwards in multi-storey buildings, despite occupants’ possibility to control the temperature. Due to upward air temperature gradient in rooms there will be a heat transfer through slabs upwards. The size of this depends on insulation degree of building envelope and slabs and air flow through the building. With a linear mathematical model, considering 1 m² floor area, it is shown how some parameters affect the heat transfer. Starting position for the model is a building in the thermal balance from which deviations are calculated. The model gives, for a basic case, results that agree well with the measured values. The vertical temperature increase, results in lower temperature in lower storeys and higher temperature in upper storeys. Total temperature rise for 4 – 28 storeys are in the range 0.5 – 0.7°C, which give vertical heat transfer of 0.6 – 1.1 W/m². A better insulated building envelope will increase the vertical temperature deviations. Better insulated slabs between the storeys will decrease the deviations. A building with well insulated envelope should also have well insulated slabs between storeys to limit the vertical heat transfer and temperature differences between storeys.
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