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Apartment buildings renovated with the support of Project SmartEnCity have become the most energy-efficient reconstructed apartment buildings in Estonia

Lutsu 16 maja termopilt

28 May / Apartment buildings renovated within the framework of Project SmartEnCity have become energy-efficient buildings – this is confirmed by both thermal images of the buildings and the collected data.

Preliminary comparative data shows that the energy demand in buildings has fallen by an average of 43%.

‘With the support of the project, 17 apartment buildings built in the 1960s and 1970s in Tartu’s City Centre District were reconstructed, having now become the most energy-efficient reconstructed apartment buildings in Estonia’, said Tartu Deputy Mayor Raimond Tamm. ‘The indoor climate of buildings has also improved significantly, to which the innovative CO 2 -based ventilation management in all these buildings makes an important contribution’.

In addition to a thicker-than-usual insulation layer, all residential buildings also received a demand-based heat recovery ventilation system and a roof-mounted solar power plant. During the renovation, all windows were replaced with triple-pane windows and the cold bridges around the windows were reduced. Thus, it can be seen from the thermal images taken before the renovation that the most significant heat losses by the buildings were found around the windows, in the location of the radiators under the windows, and in the panel joints. However, the thermal images taken from the renovated houses in February of this year showed evenly coloured facades, which means that there were mostly no heat leaks. In some isolated cases, minor temperature differences were observed.

The energy use of renovated buildings in 2020 can now be summarised on the basis of data collected from slightly more than half of the dwellings. Preliminary data on energy use shows that the energy demand in reconstructed houses has decreased by an average of 43% compared to the past. In total, grid electricity and natural gas have seen reductions of 27% and 58%, respectively. District heating has seen a reduction of 43% less. In fact, even less is spent directly on heating, as part of the district heating is now also used to heat domestic water, which was previously done with gas or electricity.

‘These are not definitive figures, as the renovation of several of the buildings under consideration ended a year or less ago. The final energy savings will be achieved a year or two after the end of construction – this is related to the optimization of technical systems and the drying out of moisture during construction, as well as the residents growing accustomed with the new systems’, explained engineer Kalle Virkus from the Tartu Regional Energy Agency. He added that the biggest influence on energy savings is the behaviour of residents themselves and how the technical systems of the buildings are maintained.

The SmartEnCity project started in Tartu in 2016 and has been joined by 18 apartment buildings, 17 of which have been completed. With the support of the project, a district based on smart and energy-efficient solutions will be created in Tartu’s City Centre District, where innovative solutions for district heating, street lighting and the use of renewable energy will be used.

The SmartEnCity project is funded by Horizon 2020 – The EU Framework Programme for Research and Innovation, and will run until July 2021.

Image caption: The unevenly coloured facades on the thermal pictures taken before the renovation show the uneven temperature of the outer surface of the wall and confirm the fact that the walls and windows of 50-60 year old buildings let a lot of heat through. In the photos taken after the renovation, the facades have a more uniform colour, which indicates that there are no major heat losses.

Photos by Erkki Jõgi


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Last changed 28.05.2021