Best Practices

If you own the submeters, ensure that they are calibrated within the specified manufacturer’s interval, and keep calibration and maintenance logs.

Consider the volume of water that is available from non-potable sources compared to demand for the cooling tower and the cost and logistics of reconfiguring current systems.

Non-potable water can be used as cooling tower makeup water if it has been treated to an appropriate quality to eliminate the introduction of biological contaminants. One of the biggest concerns surrounding the use of non-potable water is the increased risk of fouling.

Updating your preventive maintenance plan to include regular inspections and maintenance of cooling tower controls is a good practice.

Automatic control modulates bleed-off to match the actual evaporation rate, which is far more water-efficient than using fixed bleed rates. 

Compile monthly and annual summaries of results for each system covered.

No manual readings or temporary equipment are allowed. The submeter must electrically record readings on a ongoing basis. These readings should be relayed back to a personal computer or building automation system.

Metering must be continuous and data must be logged to allow for analysis of trends.

Electric loads with isolated circuits are often easier to submeter than natural gas equipment because you can monitor a greater percentage of energy use from a single point—which means fewer meters and lower costs.

Use the audit information to submeter those systems that have highest variability, or systems that have experienced energy management problems in the past.