Whether on a freezing winter’s morning or a hot summer’s day, heat pumps must operate reli­ably under a wide range of outdoor condi­tions. They must be able to heat and—increasingly—cool as well. Fans play a key role in this. They circu­late air through the heat exchanger and influ­ence how effi­ciently the entire system operates—not only the indi­vidual compo­nents, but also how these interact within the system. So, how well do the fan, inverter elec­tronics, evap­o­rator, and refrig­er­a­tion cycle work together? And what happens when ice forms in cold, humid condi­tions?

The Refrig­er­a­tion Inno­va­tion Center (KIZ) in Land­shut answers precisely these kinds of ques­tions. Here, ebm-papst tests air-to-water heat pumps and chillers—refrigeration units used to cool machinery and buildings—under real­istic envi­ron­mental condi­tions. The center was estab­lished in 2024/25 and Markus Gehrecke from the Center of Compe­tence Refrig­er­a­tion Cycle is respon­sible for its oper­a­tion and further devel­op­ment.

More real­istic testing

The KIZ essen­tially consists of two parts: a climate chamber and a water test bench. The climate chamber simu­lates the outdoor condi­tions to which a heat pump is exposed during oper­a­tion. It can be precisely controlled to heat, cool, humidify, and dehu­midify. The air temper­a­ture can be set from −25 to +70 degrees Celsius, and the rela­tive humidity from 10 to 95 percent. Air circu­la­tion is provided by a FanGrid consisting of four RadiPac radial fans from ebm-papst that deliver up to 21,000 m³/h, as required in the tests.

This allows for the simu­la­tion of real-world oper­ating scenarios—from freezing cold winters to hot summer days. The tests demon­strate how a heat pump reacts to changing outdoor condi­tions, and indi­vidual measure­ment data provides a more precise under­standing of the entire system. “Issues such as icing or de-icing, in partic­ular, can often only be eval­u­ated during actual oper­a­tion,” explains Gehrecke. “In the climate chamber, we can specif­i­cally recreate such situ­a­tions and deter­mine what impact they have on the effi­ciency and oper­a­tional behavior of the heat pump and its compo­nents.”

Whereas the climate chamber simu­lates the outdoor climate, the water test bench simu­lates the building side of the test heat pump—that is, the heating or cooling circuit that will later deliver heat to the house or remove heat from it. It measures how much heating or cooling capacity is deliv­ered on the water side and how much elec­trical energy is required to do so. For this, it can specif­i­cally heat or cool water and records, among other things, flow rate, temper­a­tures, elec­trical power, and heat output. These values are used to deter­mine the coef­fi­cient of perfor­mance (COP). This metric indi­cates how effi­ciently a heat pump oper­ates, or in other words, how much heat it gener­ates from the elec­trical energy consumed.

Greater reli­a­bility for devel­op­ment and customers

For ebm-papst, the KIZ repre­sents an impor­tant step toward gaining an even better under­standing of the overall system of any heat pump or chiller. In the past, it was possible to test primarily indi­vidual compo­nents. Today, complete systems can be tested—with heating or cooling capac­i­ties of up to 26 kilo­watts.

The customers are the ones who benefit the most. After all, the closer a test is to the even­tual appli­ca­tion, the more reli­able the results are. This allows tech­nical issues to be addressed even before a system is oper­a­tional in the field. “For our customers, this means we’re not just a compo­nent supplier, we’re a devel­op­ment partner,” says Gehrecke. “We can simu­late specific appli­ca­tions and work together to deter­mine what really matters during later oper­a­tion.” In Land­shut, heat pumps are already proving today what they’ll need to deliver later in the field.