Water consumption at many commercial campuses is a significant portion of resource expenditure, often with limited or no visibility into the individual branch or point of use locations, all of which summate to provide utility based reporting and invoicing, mostly on a monthly basis.
In this paper, we present a case study where a commercial campus’ water distribution system is being instrumented to obtain a more granular measure of water usage. Measurement granularity is improved both in the time domain, transitioning from monthly to hourly or more frequent reporting, and in the spatial domain with all major end loads and significant branch loads being classified or monitored. Specifically, additional instrumentation is deployed in two distinct phases. The first phase added wireless transducers to the existing utility installed mechanical meters, enabling them to transmit consumption data every quarter hour. The second phase will instrument existing branch flow meters and also insert new flow meters to certain end-point loads and sub-branches. This will enable point or clustered data polling on the order of every few seconds. We also obtain additional information by polling an existing HVAC building management system for water related points of interest.
We find that the collection and storage of granular water consumption information has the potential to create a detailed demand-side mapping of water usage on campus; providing data with significantly shortened time periods compared to the use of utility billing alone. We use this information to obtain hourly and daily consumption summaries at the site level and for specific end-load devices. From these results, we have created a hybrid consumption estimation of water consumption at the campus level, which contains a mixture of surveyed estimations and dynamic readings. This model provides improved accuracy and insights when compared to static site survey estimations. Due to the age and complexity of the site, primarily a result of numerous engineering changes over the site’s 60 year lifespan and a lack of detailed historical documentation, further work is ongoing to determine which additional endpoint loads or branched sub-sections we will instrument. We plan to use these additional data points to refine our water distribution model; hoping to accurately map individual buildings, floors and functional areas over time.
At present, our site level instrumentation has been beneficial in revealing a number of insights regarding unexpected consumption events, most of which were attributed to scheduled maintenance activities. The ongoing monitoring of individual end-point loads has also highlighted areas of significant demand, which could be prioritized for conservation initiatives, and has shown where systemic adjustments could reduce demand peaking and flatten the flow requirements our campus places on the supplying utility.