Variable speed drives and air compressors may seem like unlikely bed-fellows, but in fact the control a vsd provides can be easily integrated with an industrial air compressor. The result is a vsd controlled compressor which can vary its output according to the load and is truly controllable. Such a vsd controlled compressor (22kw) was recently installed by EDC Air Compressors at a silica sand quarry where the total C02 saving of the installation was equivalent to taking the average sized-family car to the moon and back. The payback time was also an incredibly short two years. See the fully story of the variable speed drive air compressor installation.