A vacuum cleaner includes a drive unit configured to generate a volume flow rate and a negative pressure, when energized, during operation of the vacuum cleaner, a means for determining a measure of the volume flow rate generated during operation, a pressure sensor for determining a measure of the negative pressure generated during operation, and a drive unit controller. The drive unit controller is configured to generate an operand from the measure of the determined volume flow rate and the measure of the determined negative pressure, and to compare the operand with a predefinable threshold as a design limit. The drive unit controller is operable to reduce the electrical power input to the drive unit based on the comparison of the operand to the design limit.