Guide

Water reviews, policies and action plans

Reduce water use from cooling systems

Any machinery in your business that requires cooling can be a major cost in lost water. You have a number of potential options to improve your use of water used for cooling purposes.

Cooling water flow control

You can use the manual switch to control cooling water flow, but automatic systems are also available. A control valve linked to a thermostat on your machinery will automatically switch off the water flow when the machine is idle.

Closed loop cooling water cycle

Equipment that requires constant cooling will often be connected to the mains water supply. Water is used and then discharged to the main drain. You should replace this with a closed loop system so that the water is reused if it does not become too contaminated.

Evaporative cooling towers

There are a number of approaches your business could take when using cooling towers.

  • Automatic blowdown control. Evaporative cooling towers usually operate with a continuous source of water, which keeps the build-up of impurities to a minimum and maintains cooling efficiency. Automatic systems regulate when blowdown is discharged to sewers and thus use water more economically.
  • Cooling load reduction. As cooling towers need to be periodically replenished with water, minimising the cooling load will reduce the need for fresh water make-up.
  • Spray/mist recovery. You are likely to find it more cost-effective to install automatic blowdown control than to upgrade the spray/mist eliminator.

Alternative cooling processes

You can replace conventional cooling towers with:

  • air blast coolers, in situations where 'cooled' water temperatures - of up to 40 degrees Celsius - can be tolerated during the summer months
  • refrigerated closed loop systems

Pre-heating boiler feed water is a good use of waste low-grade heat. Heat exchange with incoming cold water can often achieve lower temperatures in the cooling circuit than in cooling towers.