Variable speed drives give better control, reduced energy consumption and more flexibility.
Pumps and fans offer the best energy savings potential of any equipment in the building services industry. A fan running at 80% speed only uses 50% of the energy, compared to one running at full speed. Yet far too many pumps and fans run continuously at full speed, with the output regulated by inefficient throttling devices such as vanes or valves. A mere 20% reduction in fan speed can reduce energy consumption by up to 50%. Applied to a 75 kW motor in continuous duty, this means nearly £15,000 per year in saved energy on one single example.
As much as 20% of energy could be wasted through the use of inefficient throttling mechanisms.