These two types of compressors are set apart by their motor speeds – or rather the ability to modulate them.
As the name indicates, a fixed-speed compressor can only run at full speed once it is turned on. That’s great if the respective application requires it to operate at full capacity. But what happens if a lot less compressed air is needed? In that case, fixed-speed compressors become inefficient very quickly.
The reason is that they waste energy (and therefore money) when starting up and during “unload” (when they continue to run but produce less/no air to accommodate for reduced demand).
This type of inefficiency and waste is especially pronounced if there is a great fluctuation in terms of demand – for example in a multi-shift operation.
Variable speed drive compressors, however, can increase or decrease their motor speed based on the respective air demand.
If less air is needed, they slow down – and therefore also use less energy. While this seems like a simple thing, it was considered to be quite an engineering feat when Atlas Copco developed the very first VSD compressor more than a quarter century ago.
Since then, the market leader has come up with even more innovative ways to take full advantage of this energy-saving technology.
As a result, modern VSD compressors can save previously unimaginable amounts of energy – and therefore also reduce operating costs substantially.
By how much, you ask?
Quite a bit. After all, energy expenses account for up to 80% of a compressor’s total cost of ownership.
And, seeing how VSD compressors can reduce that energy consumption by up to 60% (depending on the model), it is very clear that these savings offer an enticing return on investment.
