The idea of VSD (Variable Speed Drive) compressors ‘paying for themselves through energy savings’ is attractive to most – but are VSD compressors the best option for your business?
VSD compressors have been designed to produce air as needed. The speed automatically adjusts so production of air matches real-time demand – perfect for those whose need for air fluctuates throughout the shift.
This is where the ‘potential’ energy savings come in. Unlike a Fixed Speed Compressor which runs at a constant speed until turned off, the VSD will decrease in power when not in use. Which should save you on power costs, in theory. However, there are so many variables, you may not see any savings at all.
VSD compressors are most efficient when running between 40 and 80% load. Outside this, the air-end is running beyond its optimum. VSDs are also sensitive to adverse atmospheric conditions. The quality of power supply, voltage and frequency also needs to be considered. So, unless you are running at optimal load, working in a cool and clean environment with a clean and uninterrupted power supply, then a VSD is probably not for you.
When VSD compressors fail, they can be expensive and time-consuming to repair. Models are often superseded within a few years, along with their parts. Therefore, you are stuck with a broken compressor that isn’t all that old but would be worth more as scrap metal.
If you are sold a VSD with the promise of dollar savings through energy savings, ask the supplier to stand by their claims. Record your actual power usage over a standard month from your existing compressed air system and if the new VSD does not reduce the power usage by what they told you, ask them to pay the difference – we bet they won’t!
So, in the right application and environment, VSD compressors will consume energy and can save you energy costs. However, they are NOT a one-size-fits-all solution and the decision to purchase shouldn’t be taken lightly. Research and analysis are required.
Are you having trouble deciding whether a VSD or fixed-speed compressor is better for your business? Contact Air Powered for a full Compressed Air Audit to determine which compressed air system is best for you. Let us help you reduce downtime – We’ll keep your business running on air.