Energy saving compressors unit -Is a VSD compressor unit the best solution?

Can a Variable Speed Drive (VSD) compressor lower the operation cost or create higher costs in other fields than energy?

Reducing the energy costs is becoming priority #1, so no wonder that popularity of VSD compressor units is increasing. There is a common belief that VSD compressors are the most efficient part-load rotary screw compressors. As much as I agree with the high qualities of VSD compressors, I cannot stress more the importance of fine tuning and adjusting the compressor unit to the field working conditions.

For example, if at full load, a VSD compressor increases power draw by 2%. The way to compensate for this loss is by using a permanent magnetic E-motor, which has a saving of 4%.

Fine tuning of a compressor unit is the key to saving energy; searching for the optimized result: cooling energy vs. input energy. 

Fine tuning is the last task in the compressor unit building process. I need to admit that in some cases a compressor unit well optimized for energy saving might be up to 35% more expensive than a standard VSD compressor unit. So what is the reason?

The answer is not only the component’s design, investigation, research and development, but also the flexibility in the co-operation of the components. Most importantly, some compressor units are not sufficiently suited with some composition systems, so the best performance over the whole working area is not achieved.

In most cases, the initial purchase price of a VSD compressor unit only accounts for about 20-30% of the total cost of ownership over 35 years. The majority of the cost comes from the electricity used to operate the machine and also the unit’s maintenance. A flexible, well balanced and efficient compressor aggregate can be the difference between quick payback time and  a negative result in the investment in the first  5 years.

You can either pay more for quality and flexibility up-front, or add the modification to your compressor after a few years of service. However, modifications afterwards are, in general, more complex and therefore more expensive. Besides the stress of this, loss of production time before action will have a negative effect on your total investment.

If you have questions regarding your new purchase, don’t hesitate to take advantage of our new consulting services, we will be happy to help you.

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