“Planning for tomorrow today”
Running the Elbtower carbon neutral
The Elbtower is a technical masterpiece, from its construction phase right up to the tower’s operation. In this interview, Joachim Kuhn, CEO of TechDesign, explains why this high-tech building will be operated carbon neutrally.
You plan the technical building equipment of high-rise buildings throughout Germany. Now you are responsible for the energy concept and air conditioning at the Elbtower. What is the difference between this and your other projects?
We’ve been planning high-rise buildings for generations, but the Elbtower is a real beacon. A project like this doesn’t happen every year, but at most once a decade. That’s partly because of the size. On the other hand, the demands placed on the tower are very high. The client wants innovations. Planning today for tomorrow, that really fits in. At the Elbtower, we can really let off steam in terms of innovation.
Why is this energy concept so innovative and sustainable?
We are particularly energy-efficient; the energy that is distributed is just the amount required. In addition, we heat with cold water and cool with hot water. This might sound contradictory, but it ensures that we can integrate as much external energy as possible into the energy supply. We use carbon neutral district heating and wastewater heat from Hamburg’s sewage system. Both energy sources are theoretically capable of supplying the Elbtower on their own. In addition, we also use green electricity exclusively. All this makes the Elbtower’s operation carbon neutral.
For buildings of this type, which requires more complex planning: heating or cooling?
Buildings of this type are specified for users with higher IT requirements, such as banks. The challenge here is the cooling. And it’s always easier to plan a building if you know the future users. This is different with the Elbtower because many users have not yet been determined. That’s why we have to plan for a lot of flexibility, without wasting resources. I could, of course, install twice as much system technology, but that would simply be uneconomical.
»We've been planning high-rise buildings for generations, but the Elbtower is a real beacon. A project like this doesn't happen every year, but at most once a decade. «
What is your process then?
In the Elbtower, the major energy consumers are the ventilation and air-conditioning systems. We therefore plan the supply lines, which run through the building like arteries, with sufficiently large cross-sections. This applies to all heating, cooling and ventilation systems. As a result, the shafts may take up a larger area, but the system technology, including the supply of the utilization units, is then correspondingly efficient.
How does that affect the user?
The requirements are quite different, depending on whether people work in a single office or in a large co-working space. We plan the technology so that we can adjust temperature and air volume as required, whether it is for small rooms or for open spaces. Multi-sensors show in detail how many people are in a room at a time and what the air quality is. Then the air volume and room temperature are automatically controlled by heating-cooling elements. The ceiling cooling systems we install offer the advantage of being able to heat and cool quickly. We are also using new technical components that didn’t exist before. One example is the air vents, which regulate temperature and provide ventilation in the rooms even in the tightest corner. We have completely redesigned these together with the component manufacturers. Now, they are very efficient and extremely quiet. And because the air enters the room close to the floor, the change in room temperature is quickly noticeable to sedentary office workers. For us, it’s very important that the technology in the building is not too complicated and that the operator can control it.
So these are innovative systems, some of which are not yet available on the market …?
That’s right. In some cases, we don’t know until very late what we are going to install, especially when it comes to room automation and smart building technologies. But that’s doable because the project is planned very sensibly, and the timeline was conceived for the long term. Digitalization and good planning methodology also helps. We’ve been working very digitally for 30 years, right up to model-based planning (BIM). In the Elbtower’s case, the client and architect are involved too. David Chipperfield Architects (DCA), for example, changed its entire planning in the design phase and built up a brilliant team with exactly the right people to create the conditions for this via the architectural model. That was top performance, and we really enjoyed the collaboration.
If you’re planning technology today that’s not yet available on the market – how do you ensure that it will be available when the Elbtower opens?
I rather worry that some old technology will no longer be available due to extremely long delivery times. It’s different with innovative technology. It will come onto the market and be ready more quickly. Since we are completing the procurement this year, availability should be possible by 2025.
How long will the Elbtower keep you busy for after completion?
Currently, around 30 people in our technical building services team are working on the Elbtower’s planning. The Elbtower will be partially handed over in 2025, planning for the tenants will take until 2026, and operational optimization until 2027. So when the building is finished, we’ll have a two-year follow-up period. But I assume that the Elbtower will continue to keep us busy, simply because it is so outstanding.