Unfreeze the assets in your cooling system
Published: 08 July, 2011
Too often under-performing cooling systems are replaced in the name of energy saving. Nigel Hallett, managing director of process cooling specialist IsoCool, argues that this approach can be a false economy.
Rising fuel prices and the economic downturn have placed operating costs under immense scrutiny, and environmental concerns have added to the pressure. Not only are manufacturers working towards targets set by the Climate Change Agreement, but they are also expected to demonstrate eco-credentials as a matter of course. While the environment is clearly a priority for everyone, energy efficiency will also be the key to the long-term profitability of the industry.
Finding more creative ways to reduce energy consumption and increase output is essential. While it’s true that new technology offers greater efficiency, manufacturers should consider ‘unfreezing’ the latent value within their existing cooling system before ploughing ahead with wholesale changes.
Effective process cooling doesn’t necessarily mean ripping out an old system and replacing it with a brand new one. The environmental and financial impact of a complete refit can be substantial and is not always warranted. This may sound contradictory coming from a company who offers such a comprehensive product range, and indeed we are proud to work with world leading brands, however as energy consultants we know that partial upgrades can deliver significant results.
Take Moss Plastic Parts for example. A leading manufacturer and distributor of protection and finishing products, Moss has 130 injection mould machines working around the clock. Historically a large forced air system cooled the hydraulic circuit, while chillers maintained the mould cooling system at a constant 15°C. Both systems operated completely independently. After close analysis, we identified that the spare capacity in the air blast coolers could be used to pre-cool water in the mould circuit if bridged by our IsoFC heat exchanger. This significantly reduces demand on the chillers and they now automatically switch off entirely or partially whenever the external temperature is below 15°C.
In addition to extending the longevity of the chillers by 30 – 40%, Moss estimates they will save in the region of 302,000kW hours, which equates to about 50% of the energy previously used to chill the water. This will contribute significantly to Moss’s energy reduction target from the CCA, where they will receive an 80% discount from their CCL if successful. Even without this, Moss will be saving approximately £36,000 per annum.
Another example of where our recycling approach to cooling has repaid dividends is with Alma Products, a leading provider of extrusion, thermoforming and container printing services to the food industry. We saw an opportunity to re-commission the redundant cooling tower utilising existing pumps and retrofit a separate plate heat exchanger to their Montair chiller system. In this way we were able to use the tower as a free-cooling source during times of the year when the ambient allows partial and up to 100% direct air-cooling.
Steve Ellis, operations director at Alma Products explains the difference this has made to their energy savings: “We used to have the chillers running all year round. Now, as soon as the temperature is below 16oC, the cooling tower and plate heat exchanger kick in and offload the compressors. Below 10oC we run on 100% free cooling so when the temperature drops, so do our running costs – it’s fantastic”. In terms of cost-effectiveness, Alma Products are on track to reduce operating expenses by 63%, meaning the upgrade will have paid for itself within just 15 months.
Not all projects are quite as complex, however, and very often small adjustments can make a considerable difference. At the Corby site of rigid plastics packaging manufacturer RPC Containers, we retrofitted a 400kW dry air blast cooler with a plate heat exchanger for frost protection to their Montair chiller plant. This simple but effective solution provides a cooling source when the ambient will allow partial and up to 100% direct air cooling, offloading the chillers. As a result, annual running costs at the plant have been cut by 45%, ensuring a ROI schedule of just 14 months.
So whether you need to increase output, improve efficiency or update an existing system, consider the benefits of a targeted, bespoke approach that makes the most of what’s already in place. Our work has shown that improvements to existing systems, which requires a lower initial outlay, can yield cost and energy savings on a par with complete refits, without compromising on quality or performance.
For further information please visit: http://www.isocool.ltd.uk/