With its simple on/off control Frese EVA can be used for many different applications, and at the same time advantage is derived from the dynamic control principles. By means of Frese EVA the optimum flow rate is ensured in each control area. This flow rate is maintained in spite of pressure fluctuations in the system. A control area may be two fan coils for a hotel room or a calorifier for a sports centre. Energy savings due to automatic flow control, lower flow and pump pressure. Maximized ΔT due to faster response and increased system stability.