The Historic Gem Has Halved Energy Use

The building is almost a hundred years old and one of the finest gems in central Bergen. Now Telegrafen has reduced energy use on ventilation and indoor climate by around 50 percent.

– We started by installing sensors to find out what was really going on with the building, says Technical Director at Bara Eiendom, Christer E. W. Nilsen.

Needed data

At the light rail’s terminal stop in the city centre lies the property Telegrafen. The building was erected in 1927 and for many years housed Bergen’s national telegraph and telephone exchange. Telenor was the owner of the building all the way until 1998, when they moved to Kokstad. When Telenor moved, Bara Eiendom secured the historic building. They have over several stages made significant upgrades.

A couple of years ago they decided to address the building’s internal, technical qualities, where air quality and energy use were central concerns. To determine the actual conditions, Bara contacted Energy Control.

– Together with them we installed wireless sensors that continuously monitored the indoor climate and what technical systems were running at any given time, says Nilsen.

Managed automatically

The data showed that the ventilation units were running at 100 percent output during the building’s normal operating hours. After some back and forth, it was decided that the building’s four ventilation units should be replaced with modern units that could be managed based on actual demand. This was done earlier this year and the results of the work are substantial.

– Electrical energy for operating the fans in the ventilation units has been almost halved. We can now automatically manage ventilation based on how many people are present, says Nilsen.

He emphasises that this applies both to the shops on the ground floor and the offices on the upper floors.

– The data from the sensors first gave us the insight we needed to take the right steps. Then the sensors took over the management of the building, and we therefore now manage ventilation in the building based on data from the sensors, says Nilsen.

The beginning of a long journey

Although Bara has come a good way at Telegrafen, Nilsen emphasises that they are only at the beginning of a longer energy journey.

– When it comes to ventilation, we have taken the biggest steps, but there is still room for savings. Together with Energy Control we are now looking at how we can achieve further reductions without compromising the indoor climate of the building, says Nilsen.

He is also in the process of looking at better demand-based management of the district heating in the building. District heating is the building’s largest energy cost, and with the steps already taken they have started to see significant results.

– I would like to have a bit more documented figures, but preliminary figures show almost a halving in this area too. We are now going to introduce demand-based management of the water system and we believe that will offer potential for a further reduction, says Nilsen.

A prime example

Tommy Hagenes explains that Telegrafen is a prime example of what can be achieved with the use of new wireless technology.

– Parts of the building are protected, so there are limits to what physical interventions can be made. Wireless sensors attach directly to the wall without any form of physical intervention. It is therefore a very simple way to collect data from the building. We have now also put the sensors to work managing the building, says Hagenes.

He explains that there are a large number of similar buildings where the technology has significant potential.

– Not all buildings are protected, but many have a limited budget. With wireless sensors you quickly gain control over the building, at a fraction of what it would otherwise cost, says Hagenes.

Zero downtime

Nilsen explains that they are extremely pleased with the preliminary results and that they are therefore continuously considering whether similar measures should be taken in other buildings.

– We are so pleased that we are already under way with another building, and there may well be more to come, he says, concluding:

– There are some who express scepticism about wireless sensors and fear they are unreliable. That has absolutely not been a problem. The sensors have delivered one hundred percent of the time, with absolutely no downtime. We are therefore very pleased with the results, says Nilsen.

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