Project Round
Project Number
72M - 7091
Research Organisation
Australian Institute of Refrigeration, Airconditioning and Heating (AIRAH)

Improving Water Efficiency in Evaporative Coolers

The Challenge:

It is currently unknown how much water installed evaporative air coolers in Victoria waste, however, estimates indicate it could be as high as 3 GL of drinking water per year. Detailed information providing an accurate picture of the water use and the potential to minimise inefficiency would be highly regarded by Victorian water businesses.  The evaporative cooler pilot study undertaken has improved this water efficiency estimate by taking actual field measurements from a statistically significant selected sample of cooler installations. This confirmed that significant savings in operating evaporative coolers are available. The second part of the project developed publications and a training program to facilitate actions to realise these potential water savings.

The Project

Two field trials were designed and implemented using 50 residential and 50 non-residential evaporative coolers to establish the water efficiencies of these units in operation.  This study included monitoring of evaporation and purge rates for the installed units, and an examination of settings and function of the salinity control systems.  These results were combined with knowledge of the state wide installed base and current installation practices to produce total estimates of water use and to identify potential savings.

The findings from the studies were then used to develop best practice guidance for residential and non-residential customers on the operation and maintenance of evaporative coolers for the best outcome with lowest water use.

A short training course for mechanical plumbers focused on recommissioning of salinity management controls was also developed. This was supported by the Plumbing Industry Commission and will be delivered by the Mechanical Services and Mechanical Services Association of Australia.

The Outcome

The project produced a revised estimate which indicated more accurately  that 4.3 GL of water was lost each year through inefficient operation of evaporative air coolers in Victoria (2.5 GL  residential coolers and 1.8 GL  non residential coolers).

These results confirmed that there is potential to greatly improve the water efficiency in the operation of evaporative coolers through recommissioning the water management systems on already installed units, and importantly raising awareness among key stakeholders so that these potential operational water savings could be realised.

A technical guide for engineers “DA29 – Evaporative Air Cooling Systems” covering the full life cycle of evaporative coolers was published.

Two best practice guides covering residential and non-residential installations were also developed to assist end users to obtain water efficient operation with their existing evaporative coolers. These publications are available as free downloads from this link.

A Learner Guide has been produced and a training program developed in collaboration with the Master Plumbers and Mechanical Services Association of Australia to train plumbers in recommissioning existing units to obtain better water efficiency.

This project is also featured on the Victorian State Governments’ Department of Sustainability and Environment (DSE) website.

Supporting documents