Cooling towers water saving tips

A clear understanding of your water use will help to identify unexpected patterns such as leaks or faulty fixtures.

To make sure you know where water is being used at your site, follow these steps to complete a simple water audit.

1. Monitor and record your water use

Read your meter daily and record the readings to understand how your business uses water. Establishing water use patterns over time will make it easy to identify spikes in your water use that need to be investigated.

How to read your meter

• Read your meter by recording the black (kilolitres) and red (litres) numbers from left to right, at approximately the same time each day
• Calculate daily water use by deducting the previous meter reading from the current reading

We recommend additional morning and night meter readings for 2 weeks every quarter to assess that the overnight water use is acceptable for your business. If it isn’t you will need to investigate it.

Water monitoring template

Irrigation test template

2. Check water using appliances

Identify all water using devices and processes in your business and check regularly. It will help you detect leaks and faulty fixtures early on and repair as soon as possible to minimise water loss.

Look for:

• Taps and showers – worn washers, leaking fixtures
• Toilets and urinals – stuck or worn float valves
• Dishwashers and glasswashers – leaking unit, taps or plumbing
• Plant and equipment – identify wherever water is used in your business and regularly inspect

Are your appliances water efficient?

Investing in water efficient appliances will also go a long way in helping you reduce water use.

Check the recommended WELS ratings for your appliances and fixtures

3. Create a water management plan

A water management plan will help you to identify inefficiencies and potential water savings, prepare an action plan and establish a dedicated team to implement the plan. It also provides a process for monitoring and reporting on your water saving actions.

Need professional assistance?

We endorse a number of waterwise water auditors especially trained to conduct a comprehensive audit of your site. They will investigate where water is being used, where it shouldn't and recommend ways to reduce your water use.

Leaks waste water and cost your business money. They can also contribute to higher energy and discharge factor costs, as well as potential equipment or facility damage.

Check for leaks

It’s best to complete this test overnight, when most water using systems are turned off:

• In the evening, turn off any water using systems, such as irrigation. If you have processes that use water overnight make a note of these and their expected water use.
• Read your meter by recording the black (kilolitres) and red (litres) numbers from left to right.
• Read your meter again first thing in the morning.
• If the numbers have changed or you have unexplained water use (that is not the result of overnight water using processes), you may have a leak and further investigation may be needed.

Download our meter reading template

Visible leaks

Look for:

• Dripping taps
• Sticking buttons on toilet cisterns
• Check seals in urinals that no water is running
• Wet areas when no water is being used in the vicinity, for example, pooling water on the ground

Hidden leaks

Look for:

• Grounds that are much greener than surrounding areas
• Areas of lawn that are very spongy
• Wet areas in paving cracks don’t dry out
• Pressure leaks – may be visible only when plant or equipment is operating

Maintenance

Your maintenance program should include regular checking of all water using devices, including:

• Storage tanks
• Irrigation systems
• Wet areas (kitchens, amenities, laundries)
• Devices that use a float valve to shut off water supply, such as evaporative air coolers, cooling towers, pool balance tanks and irrigation tanks.

A leaking water storage tank can cause reduced water pressure or no water. To prevent this remember to regularly check it for leaks.

Making sure it’s in good working order will prevent high water bills and repair costs associated with water leaks.

Appoint an on-site maintenance person to carry out daily visual checks, looking for:

• Leaks
• Pooling water
• Rust spots
• Worn seals

Other things to consider

If your tanks are fitted with float valves be sure to inspect them regularly. A faulty float valve can cause your tank to fill continuously, with excess water running straight to waste.

Consider installing a sub meter on your storage tanks and monitor water use through daily meter readings. Investigate unexplained increases in water use straight away; as it could indicate a leak. Your plumber will be able to advise you on whether sub-metering is suitable for your water storage tanks.

When installed, default factory settings for evaporative air coolers may mean the unit is set to dump or bleed significantly more water than needed.

Ensuring your cycles are optimised will help to reduce water use. For help with this, check with your service provider.

Other tips to help you minimise water loss*:

• Ask your service provider to carry out visual inspections as part of the scheduled servicing they do for you, reporting any issues or problems they believe warrant further investigation or repair
• Check for leaks by inspecting plumbing fixtures and fittings - even small leaks can result in significant water waste over time
• An overflow caused by a faulty make-up water float valve is a relatively common leak. If you suspect a leak contact your service provider or plumber

*Source: Best Practice Guidelines, Non-residential evaporative air cooling systems - Water efficiency and conservation, Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH).

Installing isolation valves and sub-meters on all major water using processes in your facility will help you to easily monitor water use and detect leaks, especially as the facility ages and leaks become more common.

Check for leaks

It's best to complete this test overnight, when most water using systems are not in use.

• In the evening, turn off any water using systems, such as irrigation. If you have processes that use water overnight make a note of these and their expected water use.
• Read your meter by recording the black (kilolitres) and red (litres) numbers from left to right.
• Read your meter again first thing in the morning.If the numbers have changed or you have unexplained water use (that is not the result of overnight water using processes), you may have a leak.

Water balance table

The first step in being able to reduce your water use is to understand where the water is being used in your business. By entering the relevant data into a table you will be able to determine the percentage of water used in each major area. You can carry out a site audit, engage a waterwise auditor or use your site knowledge to make an estimate and then start to look for efficiencies in high water use areas.

Maintain equipment in good condition

As plant and equipment age, washers and float valves will need to be replaced to prevent leaks. Regularly check all seals as part of your site’s maintenance program and replace as necessary.

Active monitoring

Have you considered active monitoring of your water use through a building management system? Data loggers can be placed on pulse capable meters and allow you to monitor water use through your computer.

Float valve maintenance

Where equipment uses a ball/float valve, ensure that the ball/float valve is set up correctly, and carry out regular maintenance checks for stuck or broken valves to minimise water loss.

Check that the ball/float valve on the make-up line can close preventing uncontrolled inflow and that it is working correctly and not bouncing excessively.

Other ideas to help you save water

• Reinforce water efficiency messages and initiatives at staff meetings
• Implement a water efficient purchase policy, ensuing you upgrade to water efficient plant and equipment when it’s being replaced

Accounting for up to 50% of your facility’s water use, a cooling tower consumes water through evaporation, bleed off, drift and make-up water. Ensuring these processes are efficient will minimise water loss.

Watch this video to find out how your cooling tower uses water in 4 key areas:

• Evaporation – general guideline for estimating the rate of evaporation is 12 litres/minute per 100 tons of cooling load
• Bleed off – intentional release of some of the circulating water to remove suspended and dissolved solids
• Drift – water loss in the form of mist, driven by the air draft of the tower
• Make-up water – water that needs to be added (made up) to the cooling tower to replace water lost through evaporation, bleed off and drift.

Watch this video to find out how to optimise your cooling tower through 3 key areas:

• Cycles of concentration – how to optimise these for best performance
• Own the system – ensure your operation or site managers carry out maintenance checks and monitor water use
• Management support – ensure the management team is accountable and understand your water use objectives and targets