Meeting tomorrow’s cooling needs requires a more detailed look at how chillers are designed in the future, says David Birtles of Lennox
It is now becoming clear that demands on chillers are changing and, consequently, the way we think about their design also has to change. At the heart of these changing demands is the need to offer lower life cycle costs and to reduce the environmental impact of ac and process cooling.

So the only option is to ‘revisit’ the way we put chillers together and to address every component and every aspect of their performance. This was the thinking behind the concept chiller which Lennox exhibited at IKK. This encompassed a number of technologies that are not yet ready for market but are on their way. It incorporated 30hp scroll compressors using R410A refrigerant.

Clearly, the chiller of the future will offer optimised performance and be combined with sophisticated controls to offer a high COP at all load – not just full load.

Heat exchangers make a vital contribution to the overall performance of a chiller and we can expect to see major advances in this area. In particular, the brazed aluminium microchannel (BAM) heat exchangers have a great deal to offer. Combining compact, low weight technology with very high heat transfer, BAM coils allow the use of much smaller condensing units to achieve the same system performance. As a result, it is possible to reduce refrigerant volumes by up to 40% with no compromise on performance.

Smart acoustics

Also destined to bring significant benefits are new ‘smart acoustics’ technologies being developed by Lennox that allow the user to strike an onsite balance between parameters such as building load, environmental issues and acoustic requirements.

Longer life with lower costs

In addressing the life cycle costs of chillers it’s important to look beyond the energy efficiency to take in the whole life of the plant from manufacture and installation through to end of life. So manufacturing processes have to become more efficient and less wasteful; with as many by-products being recycled as possible.

Installation also needs to be optimised through features such as ‘plug and play’ operation and integrated hydraulic kits that simplify installation work. The chillers themselves also need to be tough enough to withstand the elements and eliminate the need for rooftop plant rooms, thus saving on overall construction costs.

Similarly, access to all components needs to be quick and easy to facilitate both the speed and efficiency of maintenance. Inherent in this approach is recognition of the importance of efficient maintenance in maintaining ongoing efficient performance and long life of the plant. Last, but definitely not least, are the controls. These must be powerful and sophisticated at their core yet simple at the interface with the end user. Huge amounts of energy are wasted through chillers not being controlled effectively and this is very often because the end user doesn’t understand how to go about it.

Lennox UK

01604 669100