Free Cooling Upgrade for Expanding Scotland Dairy Saves ££££££s

The Client –

Dairy farm based in Scotland

The Challenge –

Upgrade cooling system and future proof facility

The Solution –

Custom designed solution with free cooling 

Keeping operational costs low whilst maximising production capacity are key considerations for clients within the food & beverage sector. One of Scotland’s largest, independent dairy farms, invited Aqua to propose a new, energy efficient, cooling system that would support their expanding product range. 


The dairy had installed a new ultrafiltration (UF) plant to facilitate in production of their protein yoghurt product. Ultrafiltration is one of four different membrane filtration processes used within the industry. There were two legacy chiller units on site, along with heat exchangers. One heat exchanger was being upgraded with a new scrape surface version. As a result of these changes, cooling capacity needed to increase to ensure -3°C glycol could be supplied to the process tanks, UF plant and heat exchangers.  


Aqua designed and supplied a custom designed solution, comprising two air cooled Aqua Pro Plus packaged chiller units, and a stand-alone free cooler.

Aqua Pro Plus Chillers

Our Aqua Pro Plus chiller units incorporate high efficiency scroll compressors, giving ultimate capacity control when compared to large screw compressors. Each unit has two independent circuits, with 3 scroll compressors on each.

Whilst the chillers are efficient just by themselves, the ability to add free cooling to the system boosted potential energy savings even further.

The dairy process was able to be configured to include a separated return from the ultrafiltration plant and heat exchangers.  This resulted in an average return temperature of 18°C, making free cooling a possibility.

Free Cooling Benefits

The free cooler can be used to precool – or completely cool – the return water. When the ambient temperature is above -6°C (but below 16°C+), partial free cooling is achieved. But, once the ambient hits 7°C, total free cooling occurs. If the process is running with free cooling, it eliminates the need for the chillers to operate which reduces energy consumption, operational costs and carbon footprint.

A significant benefit with the system is that the chillers will work at part load (or less) for most of the time. This subsequently increases equipment lifespan and keeps maintenance costs low.

Low GWP Chillers

But the benefits don’t stop there. Our Aqua Pro Plus chillers use R454b refrigerant, with a Global Warming Potential (GWP) rating of just 466.  That’s an incredible 78% less than the GWP of R410a refrigerant.

The system includes two-way control valves, adding automatic control to the process. Valves installed on each process vessel ensure cooling is automatically directed to where it’s needed. Plus, it allows different vessels to have different temperatures. Because the valves only open to allow fluid in when the tank requires glycol, energy used is considerably less. 

Finally, two inverter driven pumps, on run and standby basis, were incorporated, along with extra connections so that, should production expand further, additional pumps can be easily added.

“This is a great example of how a legacy cooling system can be upgraded to achieve fantastic year on year energy savings” explains Scotland Sales Director, John Lowe. “It also illustrates how our Sales, Hire and Service teams work together admirably to achieve the best result for the customer.  We supplied a chiller from our rental fleet to tide things over whilst we were awaiting arrival of the permanent equipment and our Service department will support the client for years to come with an extended Planned Preventative Maintenance agreement.”


£80,000 Saving Per Year

From the outset, the dairy has a more efficient, robust, and future proofed process. They also achieve an enhanced level of quality control on the end product. The run and standby pump configuration gives reassurance that production can continue, uninterrupted, should a fault ever occur.

As far as energy savings go, the free cooling cost £60,000 in capital outlay.  We predict the dairy will save £80,000 each and every year, giving an extremely short payback term. 

It’s worth noting that our client was offered a less expensive solution by another supplier.  This was based on using chillers that aren’t specifically designed for process applications, and with no provision for free cooling.  Whilst the capital outlay was less initially, the technical benefits and ongoing energy savings achieved by our system offer far more in the medium and long term.

For more information on our energy saving process cooling systems, call the team on 0333 004 4433.

Free Cooling Upgrade for Expanding Scotland Dairy Saves