How GROHE Is Pioneering Power Shower Head Technology

GROHE engineer Mirja Bensing says that a good shower experience is of utmost importance to her. This comes as no surprise, since she works in shower spray development. As an engineer, she tests both prototypes and end products. She is also involved in product development too. Recently, Mirja had a groundbreaking idea for creating more efficient shower heads: the GROHE shower lab. Bensing is developing a framework for testing shower head designs. Her aim is to improve shower experiences in general, while driving efficiency at the same time.

“We’re always testing shower heads with new spray types for defects and functionality,” she says. “Nevertheless, until now, we've never examined how good our spray patterns really are and how we can optimize them further. Especially in terms of protecting the environment.”

Simply reducing the flow is not enough to save water. Anyone who has tried to rinse shampoo out of their hair at the pool knows that it takes much longer when there is less water coming out of the shower head. As a result, Bensing is looking into a test system for how showers might look in the future. Following her proposal, GROHE and shampoo manufacturer Henkel have joined forces to develop the GROHE shower lab. Tests are now being carried out using Bensing’s simple but effective system. The search for the best eco shower head design has begun.


The shower lab is made up of two identical test benches - one at GROHE and the other at Henkel. This allows for the two independent results to be compared fairly. The shampoo company conducts their experiments from a chemical angle, while GROHE approach the problem from a technical standpoint. GROHE examine everything related to the shower head itself, as well as inspecting the cloudiness of the water before and after the rinsing process. They also investigate flow consistency, especially with low water pressure scenarios in mind.

Mirja built the GROHE test bench herself. Her shower lab is located at the back of the huge GROHE lab complex and resembles a small shower stall. On the floor is a Henkel-sponsored doll’s head. The doll's short haircut reveals the substantial number of shampoos and rinses that it’s already enjoyed through its short lifetime. Another, still-intact head with slightly longer, real hair is already waiting in front of the shower for future use.


The concept of the shower lab is very simple. “Our test procedure goes like this,” Bensing explains. “We install the shower head. We make the hair wet, and then shampoo it. Next we rinse, change the head or spray type, shampoo the hair again and rinse it out. Finally, we compare the results.”

The flow rate is reviewed, as well as the time it takes for the water to run clear. One series of tests, for example, involves measuring how fast shampoo is rinsed out at different temperatures. The temperature is the only thing that changes during this experiment, while the spray type and water flow remain the same. With only a single variable, Bensing and her team are able to decipher exactly where differences in their results are rooted.

One small piece of plastic plays an important role in these tests: the flow regulator. It is built into the majority of GROHE power shower head models and is indispensable in many territories. One example would be the US market, where water consumption is strictly controlled. A water flow regulator ensures that the same amount of water is always flowing from the spray plate, regardless of the water pressure in the pipe. Considerations such as these are at the heart of Bensing's quest to create a shower head for low water pressure contexts.

Bensing's shower lab examines power shower head spray patterns.

Bensing has approached the topic from all angles. Having developed her shower lab over a year-long pilot phase, tests have begun in earnest to find the best eco shower head. Even so, before the end goal of the energy efficiency label is possible, the trial doll’s head will have to take a few more showers.

Photographer: RAMON HAINDL