The challenge - Commercial pools are large bodies of water that consume considerable amount of resources. To operate these large pools the pool operator needs to deploy industrial size boilers, pumps, chemical systems, lights, filters, control devices and other electro-mechanical systems. In most pools, these systems are not interconnected nor synchronized and operate independently from each other. Unfortunately, it is not uncommon to over or under heat the pool, or accidently drain thousands of gallons of pool water due to a late discovery of mechanical failure in the filter backwash system. In a worst case scenario pool operator may expose pool patrons to health hazards that can lead to unpleasant consequences due to a pool water chemical makeup that is way out of spec and unsafe to swim in. The trigger for a pool owner to call for the expensive process of pool re-commissioning, are unusual high water or energy bills that cannot be explained by the facility staff, or a catastrophic event that leads to a pool shut down by the local health and safety authorities. The problem with utility bills is that they show a month worth of usage and do not allow the breakdown of consumption by system or specific dates.
Pool Analysis - Running into this issue in almost every pool that we have analyzed, we found that the ability to measure, monitor and gather data on individual systems is a fantastic source for analyzing pool systems and reducing waste. By manipulating the continues stream of data coming from the different systems and setting min/max limits, alerting immediately the facility staff when these limits are reached, and by setting automatic responses and actions to these scenarios we are able to control the pool water and energy consumption to a targeted level. To get there our “weapon” of choice is the TEK Aquatic Controller, (by Lincoln aquatics) a PLC based control monitoring and reporting system as well as an energy performance management solution. The TEK controller pulls data from the from installed sensors like flow meters, temp sensors, pressure sensors, chemistry systems, filtration systems boilers, solar systems (PV, thermal or both), and more. These data points are being continuously recorded, logged and reported instantly. The information collected is displayed on a pool control dashboard and provides a wealth of data that is processed by the software which generates smart reports that help the facility staff track and quickly correct any anomalies showing in the report. For example, the software reports can show a graph of energy usage information over a period of time showing metrics of actual energy consumption and real time scheduling of a sub systems. The software raises red flags when systems stray out of their predefined range along with automatic actions to avoid catastrophic events.
Real Pool Case Study - One of our earliest projects was a 600,000 gallon commercial pool that has a surface area of 9,825 Sqft. The ownership had no idea how much it cost to operate, while the CFO had a feeling that the cost of operating the pool has been slowly creeping up over the years.
We were hired to complete the following:
Estimate as close as possible the pool annual operating cost
Come up with a plan to save a minimum of 30% of the annual operating cost
Any proposed plan must carry a less than 5 years ROI
To complete the task we have decided to take a 3 step plan
Step 1 - Base line the pool parameters and operating costs
Step 2 - Reduce waste where we can
Step 3 - Produce whatever we can’t save or reduce
Baseline - To base line the pool, we have installed a TEK Aquatic Controller in order to accurately sub-meter the pool boiler for gas usage, filter loop pump for electrical usage and makeup water consumption. The operating costs became clear after a few weeks of data collection:
Gas - It takes 30,000 therms annually to heat the pool, and with cost per therm = $0.93/.8 (boiler efficiency) = $1.1625, annual savings are estimated at $34,875
Electricity – a 45 HP Pump consumes 301,563 kwh annually with estimated cost of $45,234 ($0.15 /Kwh)
Water - 750,000 gallons annually are used to back wash the pool filters with estimated annual cost of ( $0.03/gal) $22,500. Disposed chemicals cost estimated at $5,000 to a total estimated annual cost of $27,500
Total estimated pool annual operating cost - $107,609
Reduce
Install a VFD on the pool pump, using lower Hz that would save 35% of pump energy consumption. A 45HP pump would reduce its consumption by 12Kwh. Total reduced Hz hours in a year 6,750 @12Kwh = 81,000 Kwh saved with estimated annual savings of $12,150
Schedule the Pool Boiler to reduce an average of 5,000 Therms annually with estimated annual Savings $5,800
Produce
Install a 200 Collector Solar Thermal system to produce 22,000 Therms /Yr. The solar system carried a $72,000 rebate with estimated annual gas Savings of $25,575
Install water recycling plant to save 95% of the water and chemicals wasted with estimated annual savings of $33,250
We have presented our plan to the ownership with estimated total annual savings of our grand plan to be $76,750 which represent over 70% annual savings on operating pool cost. After reviewing our proposal and considering cost, available space and resources, the owner opted for the following parts of our proposal:
Install a Solar thermal system - $250,000 with CSI Incentive of $72,000
Install a VFD on the main pool pump - out of pocket $15,000
Schedule the pool boiler – expense was covered under the solar system controls
Total out of pocket cost - $175,000
Annual savings - $43,500
ROI – 4.02 yrs
In addition to the annual savings the owner got to benefit from the following:
Internet Connected & Monitored pool system
Complete pool dashboard to monitor& diagnose:
Pool Temperature
Filter loop and solar flow rates
Solar BTU Production
Boiler BTU Spent
Chemistry usage
Make up water consumption
Data Logging of all relevant parameters for future reference
Alarms via txt/ email and automated actions
Remote control
Filter Loop pump schedule
Load Shedding
Backwash automation
Summary
By retro commissioning a pool, the owner will benefit from the following:
Improved system operation
Improved equipment performance
Increased operations & maintenance staff capabilities and expertise
Increased asset value
Energy savings
Water
Improved environmental control
Improved occupant comfort
Improved indoor environmental quality
Improved building documentation
Reduced operating and maintenance costs
Reduced maintenance/troubleshooting issues
Reduced energy expenses
Improved controls over the building’s mechanical systems
Constant improvement of equipment optimization
Automated record keeping