Efficiency VS Value VS Greenstar and then the technology behind these systems can sometimes be confusing. The speed at which modern equipment changes and evolves means what equipment you used and specified last time might not be the best in 2015. We’ll try to demystify these options and give you a road map to how to choose you next chiller.

 Clivet air cooled screw chiller 

The topic is largely open to individual preference and frequently debated but the underlying method for which is best for each application “methodology” is the target of this article.

The best product is either all of the above or none of the above! This is because to achieve the best result no one product or solution can claim itself to be a 1 stop solution. Each project should be checked for what it needs and what are the goals of the customer.

In general:

  • Scroll systems tend to be lower investment, older scroll solutions poor efficiency, modern scroll high efficiency. Scroll compressors are smaller and lighter and can be easily replaced but cannot generally be repaired.
  • Screw systems are longer proven, higher cost but perform well in many applications
  • VSD systems typically used on screw compressors require higher capital cost, give slightly higher efficiency compared to scroll.
  • Magnetic bearing turbo compressors are generally the highest cost. In water cooled applications they give the highest efficiency and in air cooled applications while still high efficiency the gap is smaller. In very high ambient conditions with air cooled their efficiency can also be lower.


What is your main driving factor?

If you blindly seek efficiency at all cost, then VSD or magnetic bearing will probably win, however if cost benefit and total cost of ownership are key factors then these technologies are not always the best due to their relatively high investment cost.

How do I compare these technologies?

The main comparison can be done in a highly analytical way through energy simulations and using part load efficiencies but at the very least should consider simplified seasonal changes and loading.

An example of such an analysis can be downloaded here:



For more information contact our technical staff.