AF Bostäder works intensively to reduce energy consumption. The focus is on properties built before 2009 and the aim is a 15 % reduction in energy consumption among the older properties in the portfolio by 2019.
AF Bostäder’s newly-built properties are constructed with a requirement that they will use 15 % less energy than the National Board of Housing, Building and Planning’s requirement. Whereas AF Bostäder’s new construction requirement is 64 kWh per m2, the older properties can use as much as 195 kWh per m2, which explains why these properties are the top priority.
“We have run a project at Kämnärsrätten since 2015 in which we measure the room temperature in 25 % of the apartments,” says Staffan Jacobsson, Technical Services Manager at AF Bostäder. “The average temperature of the apartments then automatically controls the heat flow temperature to the radiators. This method reduces energy consumption. Technical upgrades, such as replacing fans and pumps with more energy-efficient upgrades also makes a considerable difference. All our buildings are now computerised and connected via built-in, fully graphical web servers, which gives us the possibility to optimise the operation of our heating and ventilation systems. We have everything monitored in real time, 24/7.”
AF Bostäder has also installed a new geo-energy unit in one of the properties at Kämnärsrätten. The unit consists of two heat pumps and 14 energy wells, which take heat energy from a depth of 250 metres below ground.
“The unit covers almost the whole building’s heating requirements,” says Staffan Jacobsson. “Compared with electrical energy, we obtain four times as much heat energy using geo-energy. The unit is a considerable investment, but provides a total saving of SEK 8.5 million over the unit’s depreciation period.”
AF Bostäder renovated 12 apartments at Studentlyckan in 2017.
“Among other things, we have replaced the older natural ventilation with modern kitchen fans,” states Staffan Jacobsson. “The fans contain FTX units, which ensure that the warm room air heats up the fresh air from outside to 18 degrees. This provides about 80 % energy recovery.”
Ever since the early 2000s, AF Bostäder has conducted various water-saving projects including the installation of low-flow taps and shower hoses. AF Bostäder has also replaced the adjustment valves for hot water circulation in almost 500 apartments at Kämnärsrätten, so that hot water is supplied immediately, without having to run cold water through taps or shower hoses first.
“An important complement to our efforts is to engage our tenants. We have, for example, produced a film called Värmeresan (Heat Flow). The film covers areas such as how to air a room, how to furnish a room to avoid blocking the heat flow and why you should never close your ventilation when you are cold,” says Staffan Jacobsson.
Three years have passed since the target for increasing energy efficiency was set, and so far AF Bostäder has reduced the energy consumption in its older properties by 6 %.