Measurement and Verification

While components of Aqualogix exist on the market today, there is no other end-to-end solution for cooling tower water management that encompasses Aqualogix’s suite of features. The specific parameter that should be evaluated is simple – the amount of metered water savings versus the baseline.

The minimum requirement for an Aqualogix building is a cooling tower. Other qualifying factors include:

• High cooling tower loads (tons) – Higher loads, especially steady ones, lead to greater potential Aqualogix savings (kGal).
• Water cost – Buildings in jurisdictions with high water costs can enjoy accelerated paybacks on Aqualogix implementations.

  Sewer charges – Depending on the local authority, sewer charges may apply to evaporative loads, further increasing the benefit of Aqualogix.

• Water quality – Aqualogix includes side stream filtration that lets towers run at higher cycles of concentration, which generates savings.

Our methodology for deriving quantitative benefits is a direct measurement of water savings that complies with M&V Option B of the FEMP M&V Guidelines, Version 4.0. The method is the same for any Aqualogix building and relies on at least one month of baseline cooling load profile development and ongoing post-installation performance monitoring to ensure the persistence of savings.

Baseline cooling load profile development

We establish the baseline by measuring the cooling tower load (ton-hours) and the cooling tower makeup water (gallons) in 15-minute intervals using portable, non-invasive ultrasonic meters. The meters accumulate the tower load and makeup water volume for a period of 30+ days to document performance over a range of outdoor conditions. The baseline evaporation is equal to the baseline cooling tower load multiplied by 1.8. The excess water ratio, which is our proprietary term for explaining a cooling system’s water efficiency in a single number, is the baseline makeup water divided by the baseline evaporation. The balance of the makeup water is non-evaporative (i.e., blowdown and leaks).

Ongoing post-installation monitoring for savings persistence

Aqualogix automatically trends metered data for makeup water and cooling tower load and uses the data to verify performance and ensure that savings persist. The savings that result from the installation of the Aqualogix system are clearly demonstrated in the metered data and can be normalized based on cooling load in the event of significant shifts in annual loads.