19.12.2017 | By Mikko Lehtinen

Company: Bengt Dahlgren
Project name: Karlatornet
Location: Gothenburg, Sweden
Schedule: 2021
Customer: Serneke
Architect: Skidmore, Owings &Merrill
MagiCAD software: MagiCAD Piping and MagiCAD Ventilation for Revit

When completed, the tallest building in the Nordic region, Gothenburg’s 73-storey Karlatornet, will stand 245 meters high.

– “Managing water pressure in such a tall system requires a lot from the design of the building’s piping network”, says CAD Manager Mattias Torberntsson at Bengt Dahlgren, Gothenburg.

The Swedish engineering consultancy Bengt Dahlgren designed the building’s piping network, including sprinkler and cooling systems, and control and monitoring systems, and performed also energy calculations for the building. The design was carried out using MagiCAD Ventilation and MagiCAD Piping on Revit technology.

– “Because we performed early-stage design directly using MagiCAD, the model already included calculations and drawings before detailed design even began. This avoided unnecessary overlap, as we did not need to transfer traditional predesign to MagiCAD separately. In this type of sizeable project, there is always a large number of different calculations involved. With MagiCAD, we began saving time right from the early stages of the project”, says Mattias Torberntsson.

Challenges
Designing piping and ventilation for a 73-storey building is complex and demanding, and because of this, the project required top-level expertise, technical knowhow and experience from the designers. One of the greatest challenges was water supply.

– “We needed to get water to 240 meters. This requires a powerful piping system because the pressure becomes very high and there will be a large difference in pressure between the ground and top floors of the building. This was solved by designing a system divided into subsections. The water will be pumped to a certain height, collected into an accumulator, pumped again to the next accumulator, and so on”, says Mattias Torberntsson.

Also the ventilation system was divided into sections, enabling pressure to be balanced using five engineering rooms located on different floors along the height of the tower.

– ”Otherwise the pressure could get too high for the operation of the systems”, says Mattias Torberntsson.

Top-class design tools
These types of challenging projects demand an advanced level of functionality also from the design tools. This is why Mattias Torberntsson has been using MagiCAD already for almost 20 years.

– “MagiCAD is the best on the market. Many of the other available software are from the United States, but this Finnish software works very well. MagiCAD is easy to use and it has a low threshold for getting started. Above all, we are very pleased to be able to accomplish all of our calculations directly in MagiCAD instead of performing them separately. We use all of the modelling features and benefit from using, for example, the 3D Section Box function and clash detection”, he says.

The neighborhood’s own district heating network
Bengt Dahlgren was also commissioned to develop the podium building for the tower, which will include premises for Petter Stordalen’s new hotel, as well as power, air and water supply systems for the entire Karlastaden district. The neighborhood will consist of nine independent buildings with apartments and premises for offices, shops, preschools, schools and a healthcare center.

– “The whole neighborhood sits on top of a large underground parking space which will also house the power, air and water supply systems for the district. The heating, cooling and water distribution will be routed through the parking space to the individual buildings, meaning that the district will in practice be served by its own district heating network”, says Jan-Olof Johansson, senior consultant at Bengt Dahlgren.

– ”Among its other features, the system will collect and reuse the heat emitted by the area’s machine rooms by transforming it into hot water stored in large hot water accumulators from which the water will be delivered to individual apartments.”

– ”Water use always peaks in the morning when everyone starts their showers and kettles at the same time. The accumulators will cover approximately 80 percent of the showers’ water consumption”, says Jan-Olof Johansson.

Large dimensions
In order to supply the entire 300,000 square meters of the Karlastaden district with heating, domestic water and cooling, all pipes will need to have large dimensions, which means that the necessary installations will also take up a great deal of space in the underground car park. The installations will include power, air and water supply systems, sprinkler centers and accumulators.

– ”We have greatly benefited from the 3D Section Box function which MagiCAD brings to Revit, enabling us to visualise specific parts of the piping network in detail. This is a function that we use frequently in all of our projects”, says Mattias Torberntsson.

A sustainable neighborhood
Bengt Dahlgren is also responsible for coordinating the sustainability certification process for the Karlastaden district. The certification process will be carried out according to the BREEAM Communities standard and it will require a high level of social, ecological and economic sustainability from the entire neighborhood. Among other aspects, the focus will be on energy use, resource efficiency, transport, and dialogue with the local community.

Bengt Dahlgren is an engineering consultancy which offers services for the entire construction and project management process, with a dedicated staff of professionals in installation, fire prevention, risk assessment, construction, real estate, energy efficiency and environmental engineering. Bengt Dahlgren have used MagiCAD for AutoCAD for nearly 20 years and MagiCAD for Revit for 4 years, with around 150 of their designers currently using MagiCAD on a daily basis.