Energy renovation
of the Langkærparken
block of flats in Aarhus

Located in Tilst, a suburb of Aarhus, Langkærparken is a block of flats with 838 rental units. From February 2014 to August 2016, the building underwent an energy renovation project.

GK Danmark won the ventilation contract, for which Dantherm provided 838 HCV Low Sound residential ventilation systems.

Dantherm boligventilation i Langkærparken -Langkærparken in Tilst, Denmark

Measured in three parameters
GK Danmark's project manager Eik Petersen recalls that three parameters were decisive when it came to choosing a supplier of the residential ventilation systems. Not surprisingly, these three parameters were price, quality and service, and Dantherm scored at the top of the list in all three.

Setting up a test flat

The energy renovation of 838 rental units is by no means a small project. There were several moving parts that had to fit together to make the project a success. It was therefore a sound idea on behalf of Dantherm to install a finished system in a test flat in the housing block. The flats were renovated in accordance with the BR 10 standard, and one the challenges of project lay in having to install the HCV 4 systems in a cabinet located in the kitchen-dining areas. Because of this precise location, there were additional requirements for the systems' noise level, which could not exceed 30 dB(a). In this connection, Eik recalls that BR 10 includes standards for the maximum permissible noise level of a heat recovery system. Meanwhile, the same set of building regulations contains no requirements for the maximum dB(a) that a refrigerator in the kitchen-dining area may produce. But building regulations are often confusing in this way, notes Eik with a smile, as he says, "Not everything is worth puzzling over."

Innovative thinking in product development

Normally, an HCV 4 unit is not installed in a cabinet, but one was required in this case. To further complicate matters, the HCV 4 system with heat recovery could not be delivered in its standard steel cladding.

Dantherm HCV4 low soundThe maximum 30 dB(a) noise requirement prompted Dantherm to develop a new model of the HCV 4 system – a so-called low-sound model. All of the units delivered to the housing association have thus been fitted with a sound insulating material that has resulted in noise levels well below the 30 dB(a) limit, says a proud Eik Petersen, who leaves the clear impression of being quite satisfied by the product development partnership with Dantherm. And Eik knows what he's talking about: He has personally taken many measurements of the unit's noise level, and the efficiency of Dantherm's HCV 4 Low Sound heat recovery solution is proven.

Pictured here is an HCV 4 Low Sound model installed in a kitchen cabinet. The unit is fitted with a sound insulating material which allows it to satisfy the BR 10 standard

Quality and service

Price, quality and service are normally said to go hand in hand. Reasonable prices are naturally beyond discussion. But on the whole, the project manager has found that both quality and the subsequent service from Dantherm's side are also on the high end of the grading scale. Naturally, it would be impossible to deliver all of the heat recovery units at the same time in an energy recovery project of this size. The renovation of a total of 35 blocks of flats was carried out level by level, as soon as the tradesmen were ready for it. Meanwhile, the residents had to be moved to different flats. This process required a great deal of planning and many partial deliveries made under tight deadlines. Fortunately, Dantherm's deliveries were always made on time, and the ventilation systems were ready as agreed when the workers needed them.

In this regard, Eik has a clear memory of finding himself in a critical situation and experiencing Dantherm's understanding of service and flexibility. Thanks to a very service-minded attitude from the supplier's side, it was even possible to have an HCV 4 unit delivered on a Sunday, recalls a smiling Eik, who goes on to say that the quality of the delivered products was top notch. Of a total 838 residential ventilation systems, defects were only identified in 10-15 of them. Most of these defects were quickly corrected, and when repairs weren't possible, the defective units were simply replaced.

Dantherm boligventilation i Langkærparken
Eik Petersen from GK Danmark at an installed unit.

Residential ventilation maintenance

In choosing Dantherm as a supplier, it was also important that the superintendents at Langkærparken were able to receive training from a Dantherm technician in maintaining the ventilation systems and the significance of possible blinking warning lights. And thanks to this training, GK Danmark has not had to drive out to Langkærparken to see to numerous service assignments. Furthermore, it is also cheaper for AL2 Bolig, the developer, when internal employees can manage tasks like replacing a filter and other jobs.

køkken med Dantherm boligventilation monteret i teknikskab
Pictured here is a finished kitchen-dining area. Nobody would notice the cabinet in which Dantherm's HCV 4 Low Sound residential ventilation system is installed.

Resident satisfaction

The long renovation period began in February 2014 and ended in August 2016. During this time, Eik Petersen naturally spent many hours at the building site, where he had the side benefit of getting to know several residents of Langkærparken. With an ventilation contract in hand, it is sometimes easy for a busy project manager like Eik – who takes great interest in the location of the duct work and other technical curiosities – to only concern himself with measuring noise levels and other details. "But it's also important to remember that the job has more to do with people than technical matters. After all, the point is for people to be satisfied with their home ventilation system. If they're not, it can never be seen as a success from a technical standpoint without it being a real-life success," he notes.

When he thinks back on it, he remembers that the residents were initially sceptical about the energy renovation project and the installation of residential ventilation units in their flats. They had never had anything like it before. As a result, it was also difficult to see the value of the project in the beginning. However, over the course of the renovation phase, and as the residents began moving back into their upgraded flats, the initial scepticism turned to excitement. In fact, Eik found that some of the residents came to thank him for their ventilation systems. Several of them even had small gifts of gratitude for him. Today, now the long renovation phase is complete, it is clear that these gestures left an indelible mark on the seasoned project manager. One can also see this in his observation that his work is more about people than technical matters.

A continued close partnership

The positive experiences GK Danmark had with Dantherm as its supplier of home installation systems has resulted in both companies working together on multiple similar and future projects.

 HCV 4 LangkærparkenLangkærparken is no longer a construction site, but the work carried out there was comprehensive when the renovation project was underway.


Fact box:
Project: Energy renovation of the Langkærparken block of flats, located in Tilst, Denmark
Area: 35 blocks with 838 flats
Developer: AL2bolig
Architect: Arkitema
Consulting engineer: Rambøll A/S
General contractor: Enemærke & Petersen
Ventilation contractor: GK Danmark
Construction consultant: DBI

Read more about

Contact Dantherm
Send us an e-mail
Find distributors
See distributor list
Filter change
- easy and quickly
How to easily change the filters Play