Mr Hilde­brandt, you have completed over 100 projects, making you an expe­ri­enced retrofit specialist. How do you approach these projects?

Before you can imple­ment a retrofit, plan­ning and design are crucial. In this regard, we support our customers with both advice and prac­tical help. In other words, we assist them in the compi­la­tion of perfor­mance data, draw up possible concepts, and present exam­ples – including a rough cost overview. We ask ourselves: what is the whole purpose of the system? How should it be oper­ated? How can we adjust it?

Do you super­vise the retrofit until the end of the project?

Yes, of course. We plan the entire process and even split it into several parts if the project cannot be completed within a year. Then we retrofit the fan first, program the oper­ating point in the new fans, then rebuild the elec­trical system in the second step. We coor­di­nate with ebm-papst to select the right fan and the right motor. We arrange the disman­tling and the assembly steps and the process of incor­po­rating the electrics into the system. To be able to compare how the effi­ciency level has improved, we take one measure­ment before the conver­sion, and one after­wards.

Once the system is 10 to 15 years old, the retrofit has paid for itself.

Dieter Hilde­brandt, Sales Director at Breuell & Hilgen­feldt

What sorts of results do you achieve?

Once the system is 10 to 15 years old, the retrofit has paid for itself. Back in the day, many systems went into oper­a­tion without controls. But now, we can operate the fans at the exact point that the customer needs. It is now possible to achieve energy savings of 60 to 70 percent, because it just isn’t neces­sary to move so much air any more. Circu­lating air is one of our most expen­sive tasks. That’s why it makes the most sense to start with that, as the retro­fitting process is quick and easy, just like when it comes to lighting.

And for newer systems?

Even if the system does its job well, it’s worth taking a look at whether there is still some­thing to improve. A lot has changed over the last 20 years in terms of effi­ciency, not only in control engi­neering, but also in motor tech­nology and aero­dy­namics. If we take the funding that is avail­able into account, we arrive at amor­ti­za­tion periods of two to three years, depending on the size and complexity.

It is now possible to achieve energy savings of 60 to 70 percent.

Dieter Hilde­brandt, Sales Director at Breuell & Hilgen­feldt

Is it just about effi­ciency?

No. With a retrofit, we aim to achieve several things at once: savings, redun­dancy, noise reduc­tion. Main­te­nance also becomes easier, as you can access 13 small fans much more easily than two large ones. Focusing only on energy savings is a very short-term way of thinking.

What is impor­tant to you in your work?

We work quickly and at short notice, and above all, can provide customized and flex­ible solu­tions. With systems that are up to 8,000 cubic meters in size and a simple changeover, our consul­ta­tion work takes roughly half an hour to one hour. Large projects that include conver­sion can some­times take 100 to 150 project hours. I like to include the on-site service compa­nies in the process and train them, so that they can work inde­pen­dently. Collab­o­ra­tion is very impor­tant for me.