Chillers are often the single largest energy consuming piece of equipment within a building but there are things you can do to improve their efficiency, including:
Check the refrigerant charge – over or under charged refrigerant circuits will negatively impact efficiency.
Clean the chiller condenser – even lightly fouled condensers will affect energy consumption negatively.
Replace the thermal expansion valve with an electronic version.
Replace fans – with EC fans or the addition of an inverter. Water pumps can be upgraded like this too, giving a much more efficient alternative.
Utilise free cooling – use the lower ambient air temperature, when possible, to save on mechanical cooling, this helps your cooling equipment last longer too as there is less wear and tear on key parts like the compressor.