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HomeMy WebLinkAbout2015-03 Performance Audit Report: Variable Frequency Drives (VFDs) at County of Hawai'i's Department of Parks & Recreation Swimming PoolsVariable Frequency Drives (VFDs) at County of HawaiTs Department of Parks & Recreation Swimming Pools 3"► Report No. 2015-03 F December 11, 2015 JNSY OF h��Y O . • ,9 gTF•oF.siar� �0 Office of the Legislative Auditor County of Hawaii This page intentionally left blank. Dru Mamo Kanuha Chair & Presiding Officer Council District 7 T9r f,o F.HAJ3 P %LAIUUN of Pabial"i Bonnie S. Nims, CGAP Legislative Auditor Business Address 1266 Kamehameha Avenue Suite A-8 Hilo, Hawai `i 96720 OFFICE OF THE LEGISLATIVE AUDITOR 25 Aupuni Street Hilo, Hawaii 96720 * (808) 961-8386 * Fax (808) 961-8905 website: hup://HawaVicounty.Qov e-mail: publiclao(aco.Hawai'i.hi.us December 11, 2015 The Honorable Dru Kanuha, Council Chairperson and Members of the Hawaii County Council Hawaii County Council 25 Aupuni Street Hilo, Hawaii 96720 Dear Chair Kanuha and Council Members, hi accordance with Hawaii County Charter Section 3-18(d)(2), attached is the Office of the Legislative Auditor's report of our audit of Variable Frequency Drives (VFDs) at County of Hawai`i's Department of Parks and Recreation swimming pools. The purpose of the audit was to evaluate the cost effectiveness of installing these VFDs at swimming pools countywide. hi 2006, the Department of Parks & Recreation (P&R) began taking proactive cost savings measures by installing VFDs at three of its swimming pools. However, P&R has not had program objectives for reducing costs since Fiscal Year 2012-2013 and has not installed VFDs at any of the remaining pools. By installing VFDs, we estimate the County could annually save approximately $122,578 in electricity costs. Furthermore, the County should recoup installation costs within the first three years. After this point, all electrical cost savings are in favor of the County. If you need any further information, please let me know. We would like to thank the Department of Parks and Recreation staff for their assistance and cooperation during this audit. We greatly appreciate all of their valuable time and efforts spent on providing us information. Respectfully, Bonnie S. Nims, CGAP Legislative Auditor cc: William P. Kenoi, Mayor Stewart Maeda, County Clerk Clayton S. Honma, Director, Department of Parks and Recreation Deanna Sako, Director, Department of Finance Walter Lau, Managing Director Hawai `i County is an Equal Opportunity Provider and Employer This page intentionally left blank. In Brief Background A Variable Frequency Drive (VFD) is an electrical device designed to monitor and protect a swimming pool/spa filtration or water feature pump by varying the frequency or speed of the motor in order to provide a specific flow rate. Research has shown that VFDs reduce costs and usage of electricity and energy, potentially recouping the cost of purchasing and installing a VFD in less than a year. The Department of Parks & Recreation (P&R), Aquatics Division is responsible for programs and operation of nine public swimming pools. They also develop and implement a comprehensive water safety program by providing lifeguard services at County swimming pools. Why we did this audit While performing a risk assessment at P&R, we found that installing VFDs at County swimming pools could reduce operating costs. The objective of the audit was to evaluate the cost effectiveness of installing Variable Frequency Drives (VFDs) at swimming pools countywide. Kona Community Aquatics Center, Kailua-Kona, HI Photo courtesy of the Department of Parks & Recreation What we fou n In 2006, the Department of Parks & Recreation (P&R) began taking proactive measures by installing Variable Frequency Drives (VFDs) at three of its swimming pools including Charles "Sparky" Kawamoto Swim Stadium, Pahoa Community Aquatic Center (PCAC), and Laupahoehoe Swimming Pool (no longer in use). P&R has not had program objectives for reducing costs since Fiscal Year 2012-2013 and has not installed VFDs at any of the seven remaining pools. Historic average monthly electrical savings of installing these VFDs ranged from 23 percent (PCAC) to 63 percent (Kawamoto). By installing VFDs countywide, we estimate an annual cost savings of approximately $122,578. Furthermore, the County should recoup installation costs within the first three years. After this point, all electrical cost savings are in favor of the County. Management generally agreed with the comments and recommendations in this report. Their complete response to this audit can be found on pages 13: Management's Comments. L —A=Md What we recommended The recommendations identify actions for management to increase cost-effective measures at County -owned pools by: Reinstating P&R's previous program measures related to reduction of utility costs at all facilities by implementing green technologies and proactive practices, or at a minimum, develop a new program measure that addresses reduction of cost and/or energy savings. Developing and implementing a written plan for installing VFDs at all County operated swimming pools. Then incorporate the plan into future fiscal years' budget that will reflect the installation of VFDs and reduction of electricity expenditures. Table of Contents Introduction...............................................................................................................................1 Background...............................................................................................................................2 AuditObjectives........................................................................................................................4 AuditScope and Methodology.................................................................................................4 Commendations and Noteworthy Achievements...................................................................5 AuditResults.............................................................................................................................6 The Department of Parks & Recreation has not installed VFDs, which have a proven history in reducing monthly electricity costs, at seven of its swimming pools...............................................................................................................................6 Why have more VFDs not been installed?...........................................................8 What is the effect of installing VFDs?...................................................................9 What is the installation cost for a VFD?..............................................................10 Recommendations..................................................................................................................12 Management's Comments......................................................................................................13 AppendixA — Audit Criteria....................................................................................................14 Appendix B — Detailed Pool Electricity Costs.......................................................................19 Introduction The Office of the Legislative Auditor conducted this performance audit of Variable Frequency Drives (VFDs) at County of Hawai`i's Department of Parks & Recreation' (P&R) Aquatics Division pursuant to Section 3-18 of the Hawaii County Charter, which outlines the Office of the Legislative Auditor's primary duties. Performance audits typically examine the effectiveness, economy, or efficiency of a government program. They can include analyzing the services of an entire department or activity, identifying possible cost savings, identifying the outcomes achieved by a program, or comparing actual department practices against the practices called for in law or policy. Our objective in performance auditing is to improve public services provided by county government. We do this by recommending specific actions that will address the issues we raise and by providing valuable information to the public, the administration, program leadership, the Hawai"i County Council, and the Mayor. A performance audit of the VFDs at P&R was included in the Fiscal Year 2014-2015 annual audit plan based on the results of our countywide risk assessment. Variable Frequency Drives at County Pools: Introduction 11 Background What is a Variable Frequency Drive (VFD)? A Variable Frequency Drive (VFD) is an electrical device, normally wall -mounted, designed to monitor and protect a swimming pool/spa filtration or water feature pump. They also vary the frequency or speed of the motor in order to provide a specific flow rate and are installed on the electrical line between the electrical breaker panel, and the pool pump. How does a VFD work? VFDs vary the speed of a pool pump to match the pressure or flow requirements and achieve energy savings. Since pool pump systems run continuously and are typically oversized, energy consumption is high. These systems are oversized to help ensure proper filtration and chemical treatment as well as compensate for clogged filters and maximum pool occupancy. By adding a VFD, the motor speed of the pool pump can be decreased while running the filtration system's valves wide open to allow for maximum flow. When regulating flow, putting a VFD on a time clock enhances efficiency. For example, a pool running around the clock at 100 percent can now run at 90 percent during operational hours and 60 percent during non -operational hours.' This reduces energy consumption and costs. 5 1. 1 VFD Control panel at Kawamoto Swim Stadium, Hilo, HI Photo courtesy of the Department of Parks & Recreation As shown in Illustration 1, the VFD works by converting incoming AC power to DC power, smoothing or conditioning it and delivering modified power to the motor. By varying the frequency of this power, the motor speed is reduced, thus reducing both the flow rate and the amount of energy consumed. The addition of a VFD to a pool pumping system can offer dramatic potential energy savings, while protecting the motor at the same time. This is done completely automatically and without operator involvement, allowing continuous speed and flow control. The ability to adjust motor speed enables closer matching of motor output to load and often results in very large energy savings. 1 VFDs and Pool Pumps (EMA Drives and Automation) http://www.emainc.net/newsletter/vfd-s-and- up mps/ Variable Frequency Drives at County Pools: Background 12 How do VFDs reduce costs? Research and testimonies have shown that VFDs reduce costs and usage of electricity and energy. Some examples of electrical savings include: • Instead of turning off the pump, pumps can be turned down with a VFD. • VFDs are a tremendous source of energy savings while not sacrificing pump longevity or performance. • Major savings are expected in most applications as pool pumps are generally oversized by design, and must be trimmed back with proportioning valves. • VFDs protect against surges, brownouts and other on-site power issues. • VFDs work by varying the "speed" of the motor to provide the desired water flow rate. • VFDs also reduce the power company "Demand Charges" (the surcharge paid by larger power customers), so an entity will pay less for the electricity property -wide, which this savings is applied to the entire electric bill, not just the swimming pool or spa portion. • During normal operations, pumps used for circulating, filtering, and heating can be operated at 80 percent of peak capacity due to more efficient piping runs, and/or oversized pumps (51.2 percent of normal power). • During off-peak operations, some pumps could be operated at 50 percent of peak capacity while still circulating, filtering, and heating (12.5 percent of normal power).2 Z Alvaro Mendoza, Aquatic Facility Design & Optimization, Pitfalls and Opportunities (United States Swim School Association, 2013) http://www.usswimschools.org/ Variable Frequency Drives at County Pools: Background 13 Sine Wave Variable Mechanical Power Frequency Power - - - - Variable Power AC Motor Frequency - - - - - - Controller 15�U ❑I ❑A- ■❑ ® © ►❑ Power Conversion Power Conversion 10 10 Operator Interface Source: en.wikipedia.org Illustration 1 How do VFDs reduce costs? Research and testimonies have shown that VFDs reduce costs and usage of electricity and energy. Some examples of electrical savings include: • Instead of turning off the pump, pumps can be turned down with a VFD. • VFDs are a tremendous source of energy savings while not sacrificing pump longevity or performance. • Major savings are expected in most applications as pool pumps are generally oversized by design, and must be trimmed back with proportioning valves. • VFDs protect against surges, brownouts and other on-site power issues. • VFDs work by varying the "speed" of the motor to provide the desired water flow rate. • VFDs also reduce the power company "Demand Charges" (the surcharge paid by larger power customers), so an entity will pay less for the electricity property -wide, which this savings is applied to the entire electric bill, not just the swimming pool or spa portion. • During normal operations, pumps used for circulating, filtering, and heating can be operated at 80 percent of peak capacity due to more efficient piping runs, and/or oversized pumps (51.2 percent of normal power). • During off-peak operations, some pumps could be operated at 50 percent of peak capacity while still circulating, filtering, and heating (12.5 percent of normal power).2 Z Alvaro Mendoza, Aquatic Facility Design & Optimization, Pitfalls and Opportunities (United States Swim School Association, 2013) http://www.usswimschools.org/ Variable Frequency Drives at County Pools: Background 13 Audit Objectives While performing a risk assessment of the Department of Park and Recreation (P&R), we found that installing Variable Frequency Drives (VFDs) at County swimming pools could reduce operating costs. The objective of the audit was to evaluate the cost effectiveness of installing VFDs at swimming pools countywide. Audit Scope and Methodology To accomplish our objective, we: • Developed an understanding of VFD operations and its process; • Corroborated information through interviews with appropriate personnel, reviewed documentation, and performed site visits of actual pool operations; • Analyzed expenditures related to swimming pool activities; • Determined cost savings of expenditures, if any, related to pools after VFD installation; and • Determined best practices of installed VFD in related swimming pools. This performance audit focused on swimming pool expenditures related to the installation of VFDs to pumps and motors currently at three County Swimming Pools: • Charles "Sparky" Kawamoto Swim Stadium (Kawamoto). The VFD was installed during the months of June 2006 through September 2007; we therefore reviewed monthly electricity costs before and after the installation of the VFD for both Fiscal Year 2006-2007 and Fiscal Year 2007-2008. • Laupahoehoe Swimming Pool. The VFD was installed during the months from September 2008 through May 2009; we therefore reviewed monthly electricity costs before and after the installation of the VFD for Fiscal Year 2007-2008 and Fiscal Year 2008-2009. • Pahoa Community Aquatic Center (PCAC). The VFD was installed during the months from May 2013 through September 2013; we therefore reviewed monthly electricity costs before and after the installation of the VFD both Fiscal Year 2012-2013 and Fiscal Year 2013-2014 We conducted this performance audit in accordance with generally accepted government auditing standards. Those standards require that we plan and perform the audit to obtain sufficient, appropriate evidence to provide a reasonable basis for our findings and conclusions based on our audit objectives. We believe the evidence obtained provides a reasonable basis for our findings and conclusions based on our audit objectives. Our conclusions on the effectiveness of these controls are detailed within this report. Variable Frequency Drives at County Pools: Objectives, Scope, & Methodology 14 We thank the Department of Parks and Recreation's staff for their assistance and cooperation during this audit. Management generally agreed with the comments and recommendations in this report. Their complete response to this audit can be found on pages 13: Management's Comments. Commendations & Noteworthy Achievements The Department of Parks and Recreation took the initiative of installing VFDs in three of its nine swimming pools and has already proven to reduce electricity cost after installation. These three pools include: • Charles "Sparky" Kawamoto Swim Stadium; • Laupahoehoe Swimming Pool (no longer in use); and • Pahoa Community Aquatic Center. We have described details of the realized cost savings in the Audit Results section on page 6. Variable Frequency Drives at County Pools: Commendations & Noteworthy Achievements 15 Audit Results The Department of Parks & Recreation has not installed VFDs, which have a proven history in reducing monthly electricity costs, at seven of its swimming pools. In 2006, the Department of Parks & Recreation (P&R) began taking proactive measures by installing VFDs at three of its swimming pools including: • Charles "Sparky" Kawamoto Swim Stadium (2007); • Laupahoehoe Swimming Pool (2009); and • Pahoa Community Aquatic Center (PCAC) (2013) Subsequently, the VFD at the Laupahoehoe Swimming Pool burned out in December 2011 since it was stored with corrosive pool chemicals. The VFD has not been fixed or replaced and remains un -working. During this time, P&R hired a consultant to assess if County -owned swimming pools needed repairs and maintenance. The consultant issued a report titled "Countywide Swimming Pools Assessment and Repairs — September 2007" on September 27, 2007. The report identified five swimming pools (PCAC, NAS, Kohala, Honokaa, and Pahala) that required repairs including the replacement of existing pumps and VFD installation. The Department of P&R installed a VFD at the Pahoa Community Aquatics Center (PCAC) in 2013. The other four pools (NAS, Kohala, Honokaa, and Pahala) have not undergone any repairs, replacements, or installation of VFDs as of the date of this report. To determine if installing VFDs in County -owned pools resulted in a reduction in electricity costs, we reviewed the four months prior and four months after VFD installation of all utility cost data (electricity, water, gas, etc.) for the three swimming pools with VFDs. We then compared the data as shown in Appendix B on page 19, and found substantial decreases in electricity costs ranging from 23 percent to 63 percent after the County installed VFDs as shown in Illustration 2. Variable Frequency Drives at County Pools: Audit Results 16 How much has the County saved by installing VFDs? (Average Monthly Electrical Costs) Kawamoto Laupahoehoe Pahoa Community Swim Stadium Swimming Pool Aquatic Center (installed 2007) (installed 2009) (installed 2013) 23% 42% 63% Average Average Average Average Average Average monthly monthly monthly monthly monthly monthly costs prior costs costs prior costs costs prior costs to VFD after VFD to VFD after VFD to VFD after VFD Note: Variable Frequency Drive (VFD) is an electrical device designed to monitor and protect a swimming pool/spa filtration or water feature pump. They also vary the frequency or speed of the motor in order to provide a specific flow rate and are installed on the electrical line between the electrical breaker panel, and the pool pump Illustration 2 Variable Frequency Drives at County Pools: Audit Results 17 Why have more Currently, P&R neither has formal written plans nor budgets for VFDs not been installing more VFDs at its swimming pools. installed? The Department of P&R does not have a formal written plan for installing more VFDs at its remaining swimming pools and their intention for resuming the installation of more VFDs is dependent on the Department's funding and budget. The Department of P&R indicated they were planning to replace the Laupahoehoe VFD when funds were available to retrofit the VFDs in the remaining pools. However, currently no funds have been budgeted or designated for additional VFD projects. Best practices for planning and budgeting process indicates the developing of strategies; developing of capital plan; budgeting for that plan; monitoring the plan; and measuring and reporting on the results of the plan is key to successfully obtaining its goals and objectives. Illustration 3 illustrates this best practice. Strategies Performance Capital Plans Measurement Monitoring Budgets and Control Source: http://www.cippIanner.com/solutions/pages/capitalpIanninq.aspx Illustration 3 Elimination of key Program Objectives of cost reduction measures The Department of P&R Aquatics Section has not had program objectives for reducing costs since Fiscal Year 2012-2013. Each fiscal year, the County of Hawaii departments develop their departmental Variable Frequency Drives at County Pools: Audit Results 18 program objectives along with their proposed operating budget. In reviewing the County of Hawai`i's Fiscal Year 2012-2013 proposed operating budget (dated March 1, 2012), P&R Aquatics Section's program objectives listed 12 objectives. Number 11 of these objectives states "Reduce utility costs at all facilities [emphasis added] by implementing green technologies and proactive practices." Number 12 additionally states, "Reduce chemical costs at all facilities by prudent work practices, education and new technologies." Subsequent fiscal years' proposed operating budget eliminated both program objectives. In recent years, the County of Hawai"i has experienced hard financial and economic times while departmental budgets remained status quo or were significantly reduced. Hence, it would have been appropriate for P&R — Aquatics to retain and implement these two specific cost reduction program objectives. What is the effect Installation of VFDs will result in an estimated annual cost of installing savings of $122,578. VFDs? To calculate the amount of potential cost savings to the County by installing VFD controllers, we determined the actual cost of electricity for all County pools for Fiscal Year 2013-2014 (see Illustration 4, column Actual FY2014). Using electricity costs for the four months prior and the four months after the VFDs were installed, we found that PCAC's electricity costs were reduced 23 percent. When the VFD was working properly at Laupahoehoe, electricity costs were reduced by 42 percent. Using an average of these two pools, the approximate electricity cost reduction is 33 percent. We then applied this cost reduction to the remaining pools as illustrated below. By applying the same electricity cost reduction percentage for one, three, and five years, potential savings in electrical costs were $122,578, $367,735 and $612,891 respectively (see Illustration 4). The Pahala pool was not included since the local school pays the electric bill (this has not changed since the County assumed operations of the swimming pool). We also did not include PCAC in our calculation of potential cost savings since a VFD controller has already installed. In addition, we did not include Kawamoto Swim Stadium since the pool has a partial roof -like covering while all other County pools are open and exposed to the elements without any roof type coverings. Variable Frequency Drives at County Pools: Audit Results 19 Potential Cost Savings for One, Three, & Five Years By Installin VFDs Pool Actual FY2014* 1 year 3 year 5 year Honoka'a $31,916 Kohala $39,772 Kona Aquatics Center $186,843 Konawaena $46,557 Laupahoehoe $40,816 NAS $25,545 Total $371,449 Cost reduction rate as determined by historic cost savings 33% X1 x3 X5 Potential Savings $122,578 $367,735 $612,891 *Source: Electricity cost data for FY2014 was provided by P&R Aquatics Section. Illustration 4 What is the The County should recoup installation costs within the first installation cost three years. After this point, all electrical cost savings are in for a VFD? favor of the County. To determine the cost of installing VFDs at pools countywide, we reviewed several VFD distributers for VFDs and pumps and found costs ranged from $2,000 for a 3 -Phase 5 horsepower pump to approximately $6,350 for a larger 20 horsepower 3 -Phase pump. The comparable 3 - Phase 5 horsepower VFD ranged from $1,346 to approximately $5,764 for a 3 -Phase 20 horsepower VFD. We also examined PCAC's installation costs from 2013. Since PCAC is an Olympic sized pool, it required the installation of two motors and two VFDs totaling approximately $60,000. The approximate labor cost was $25,000. Hence, the total installation cost for an Olympic sized pool was approximately $85,000. The County has three Olympic size swimming pools: PCAC, Kawamoto, and Kona Community Aquatic Center. Two of these three pools have already had VFDs installed (PCAC and Variable Frequency Drives at County Pools: Audit Results 110 Kawamoto). The remaining six pools are all smaller and the specific cost of installing VFDs would depend on current condition of equipment already in use and the size of the pool. Using the PCAC installation costs, VFD and pump installation at the one remaining Olympic size swimming pool should cost approximately $85,000. Since the remaining six smaller pools would theoretically require only one pump and one VFD, we estimate installation costs at approximately half, or $42,500. Using these numbers (one pool at $85,000 and six pools at $42,500), total costs of installing VFDs countywide would be approximately $340,000. Comparing the installation costs to the potential energy cost savings, the County could potentially recoup the costs in three years (the three-year energy cost savings was determined to be approximately $367,735). When either replacing a filtration system (VFD, pump, and motor) or replacing each component separately, obtaining compatible VFDs, pumps, and motors is critical for system operational efficiency and achieving an objective for cost reduction of electricity and usage. Therefore, P&R should assess each pool's circulation system separately to determine the proper components needed at each pool to maximize operational efficiency and to recognize electricity cost savings. Variable Frequency Drives at County Pools: Audit Results 111 Audit Recommendations The Department of Park & Recreation has been proactive in installing three VFDs (one of which has since failed due to storing of corrosive materials in the vicinity) resulting in a reduction in electrical costs at those locations. However, P&R has not had program objectives for reducing costs since Fiscal Year 2012-2013 and has not installed VFDs at any of the remaining seven pools. By installing these VFDs, we estimate the County could annually save approximately $122,578 in electricity costs. Furthermore, the County should recoup installation costs within the first three years. After this point, all electrical cost savings are in favor of the County. The following recommendations address each of these areas: Develop Program Measures We recommend that the Department of Parks & Recreation reinstate its previous program measures related to reduction of utility costs at all facilities by implementing green technologies and proactive practices, or at a minimum, develop a new program measure that addresses reduction of cost and/or energy savings. Plan and Budget for Installing Additional VFDs We recommend that the Department of Parks & Recreation, Aquatics Division, develop and implement a written plan for installing VFDs at all County operated swimming pools. Then incorporate the plan into future fiscal years' budget that will reflect the installation of VFDs and reduction of electricity expenditures. Variable Frequency Drives at County Pools: Audit Recommendations 112 Management's Comments 100 William P. ken -.,i r ,ilaaY+r .. Count)) of JoaWai'i DEPARTMENT OF PARKS AND RECREATION log I'suabi Street. Suite 6 • HHo, Hawaii 96720 1808? 961-11.311 • Fax 488 9614411 December 4, 2015 Ms. Bonnie S. Nims. Legislative Auditor County of F lawair C]fticc of the Legislative Auditor 1266 Kamehameha Avenue. Suite A-8 Hilo. Naun'ri 96720 Clayton S. Houma Dirrcrur Krnneth J. Van Berge■ 1)e pur1, nuettew Subject: Performance Audit — Variable Frequency Drives at P&R S-A imnrinig fouls Dear Ms. Nims. In an effort to provide cost savings at our swimming poobs. the Depanmcnt of Parks and Recreation began taking proactive co%t savings measures by installing our first of three variable frequency drive {VFF)] unit in 2006. We appreciate you and your staflf's efforts in working collaharatively with personnel from our department to evaluate the cost effectiveness of installing these N'FD% and providing us this performance audit. Thr Department of Parks and Recreation generally agrees with the findings of this audit. The L)cpartmcni will be reinstating program objectives to reduce utility costs at our swimming pools. We ars; currently in the proccss of procuring a V F D unit at Kona Community Aquatic Center. Thi% VDF unit will be able to operate the two putttps at the lxml and is expected to provide substantial energy cwt sayings. V1'c will revisit and establish a plan for installing VFD units at our remaining pools. However. some pools arc feasible for installation Ahile certain pools arc in need of major improvements and upgmdes. With our current on-going projects, we do not have enough projects managers 10 properly oversee installation of VFDs in which a complete overhaul ofthe purl is needed. The Department reccignixcs tbrc potetllial energy savings by installing VF Ds in our remaining pools. With the results of this audit verifying the cost savings and return on inve 4ment, we look forward to utilizing this audit as a tool to obtain VFL) funding in our future budgets. Sincerely. 44yn - — Clay'ton Honma Director cmo f of-wwa�'i �s en 6quel p�psr�wrty fh+er+der ewd Er�pby+er Variable Frequency Drives at County Pools: Management's Comments 113 Appendix A: Audit Criteria County of Hawaii, Part I Volume II, the Proposed Operating Budget, FY 2012-2013 (March 1, 2012) describes the Department of Parks & Recreation Aquatics program objectives: 11. Reduce utility costs at all facilities by implementing green technologies and proactive practices. 12. Reduce chemical costs at all facilities by prudent work practices, education and new technologies. "Countywide Swimming Pools Assessment and Repairs — September 2007" consultant report by Okahara & Associates (September 27, 2007) contained recommendations for five County -owned swimming pools which needed repairs, existing pumps needed to be replaced and in addition, installing VFDs in each pool. The full report is maintained with P&R Administration, Parks Planning Division. Variable Frequency Drives Help Pools Maximize Energy Efficiency by Emily Attwood, (Athletic Business, April 2012) (http://www.athleticbusiness.com) describes the advantages of using a VFD and states in part: "People are looking for anything they can do to decrease operating costs, and one of the big ways they can make an impact is to save electricity," says Robert Kappel, executive board chair of the Professional Pool Operators of America. "And one of the best -kept secrets in the industry is variable frequency drives."... The process takes advantage of the affinity law, says Association of Pool and Spa Professionals technical committee chair Steve Barnes. For example, if a pump that turns 1,000 RPM at full speed moves 1,000 gallons per minute, when the speed is reduced to 500 RPM, it moves 500 gallons per minute. "The flow rate is proportional to the speed of the motor," explains Barnes. "But when you cut the speed in half, the pressure drops to one quarter. More importantly, the power drops to one eighth. So there's this huge decrease in energy use on the same pump running at half speed. To turn over the pool, you have to run it twice as long, but even running the pump twice as long, you're only using a quarter of the electricity."... Pools that operate year-round can potentially recoup the cost of a VFD in less than a year, and though the payoff may take longer for a seasonal pool, the savings are, more often than not, still worth the investment... Energy efficiency is already on the legislative agenda in states like California, Florida and Arizona, though laws are aimed mostly at residential pools, which have even greater potential for energy savings. But both Barnes and Kappel believe that it won't be very Variable Frequency Drives at County Pools :: Audit Criteria 114 long before the industry tackles energy use in commercial pools. Even so, with the savings pool operators stand to gain, there's no reason to wait until energy reform becomes compulsory to look into improved technology. "The time is past due," says Kappel. "If I operated a facility, I would be all over VFDs." VFD's - how they work and can save you money (Commercial Energy Specialist (CES) publication Water Quality News, January 20, 2008)(http://www.ceswatergualitynews.orq/) states in part: ..The addition of a Variable Frequency Drive (VFD) to a pool pumping system can offer dramatic potential energy savings, while protecting the motor at the same time... VFD's match the motor speed to the desired flow. The operating speed of a motor connected to a VFD is varied by changing the frequency of the motor supply voltage. This is done completely automatically and without operator involvement, allowing continuous speed and flow control. As shown above, motor -driven systems are often designed to handle peak loads and may have an additional safety factor. This often leads to energy inefficiency in systems that operate for extended periods at reduced load. The ability to adjust motor speed enables closer matching of motor output to load and often results in very large energy savings. How much can you save using a VFD? In these centrifugal pool pumps, (according to energy conservation experts) energy consumption is proportional to the cube of the flow rate. In plain English that means that even small reductions in speed and flow can result in significant energy savings. In pool applications, significant energy and cost savings can be achieved by reducing the operating speed when the filters are clean, or when the pool is experiencing off-peak loads. How great are the savings? A motor running at 50% of full speed capacity has a motor torque of 25% of full speed. In addition, electricity required to operate the motor at 50% of full speed is 12.5% of the amount of electricity required if the motor was running at 100% full speed capacity. Thus, reducing motor speed can significantly reduce the electrical energy consumption. Therefore, a pump which is operating at 50% speed in OFF PEAK times is saving 87.5% of energy used. So, in a typical pool pump -room scenario where the pump is being "trimmed", it is very common to achieve considerable peak time savings by replacing the "trimming" valve with "reducing the speed" of the motor to achieve design flow rate. As the filter gets soiled, the VFD will increase the flow rate to compensate for the dirty filter. Variable Frequency Drives at County Pools: Audit Criteria 115 Most VFD installations will pay for themselves quickly, normally payback will occur within 12-18 months. Saving Energy at the Swimming Pool with VFDs, Variable -Frequency Drives Reduce Energy Costs and Protect Motors at South Windsor, Conn., Pool Complex by Paul Miller (Control Global, May 5, 2008) (http://www.controlglobal.com) describes energy costs savings at the Veterans Memorial Pool Park in South Windsor, Connecticut: The electricity required to run these four pumps on a 24/7 basis is by far the pools largest operational expense, and tens of thousands of dollars are budgeted for utility costs each season. As a result, Tim Friend, plant supervisor, is constantly looking for ways to improve efficiency and reduce costs, while still maintaining water purity. We wanted to lower our power bills, says Friend, " We knew we were wasting energy by always running the pumps at full power—especially after hours. There are fewer impurities in the water when nobody is swimming, so by slowing the flow at night, we knew we could still maintain adequate filtration in the pool and maintain the same levels of water quality... Variable -frequency drives help reduce energy costs Friend then drew on his experience operating water treatment and purification plants, where variable -frequency drives (VFDs) are often used to allow pump motors to be safely operated at reduced speeds. To find the best solution for the pools, he consulted with Brian Robinson, a sales engineer at FlowTech, a local sales and service representative for ABB VFDs. Friend and Robinson had previously worked together on a number of projects. Brian turned me on to VFDs a long time ago," said Friend. "We saw how great they worked in similar applications on several previous projects. By installing VFDs at the pool, we determined that we could reduce the motor speed, but still run our system with the valves completely open—all the while, achieving the full -flow rate we need to run the filtration systems.... After installation, the pump speeds were set back using the on -board time clocks that initiate pre-programmed, pre-set speeds in the VFDs. The crew programmed the pumps to run at 90% power during open -pool hours, and to ramp down to 60% for 12 hours each night after the pool closed. These reduced settings were expected to reduce energy consumption by 65,000 kWh per season, a savings of more than $7,000 in operational cost annually... Variable Frequency Drives at County Pools: Audit Criteria 116 Two-year payback anticipated With the energy savings the pools complex now is experiencing, Friend anticipates recouping the entire project budget, the cost of the VFDs and their installation, in two seasons. We don't have the final numbers back from this season yet, but between the energy we are saving and State of Connecticut energy grants, we're thinking the retrofit will have paid for itself by the end of next year. This is by far the best decision we could have made..." Aquatic Facility Design & Optimization Pitfalls and Opportunities PowerPoint presentation by Alvaro Mendoza of Commercial Energy Specialists (CES) (United State Swim School Association, 2013) (http://www.usswimschools.org) describes electrical savings of using a VFD: • Instead of turning OFF the pump, you can turn it down with a VFD. • Variable Frequency Drives (VFD's) are a tremendous source of energy savings while not sacrificing pump longevity or performance. • Major savings are expected in most applications as pool pumps are generally oversized by design, and must be trimmed back with proportioning valves. • Protects against surges, brownouts and other site power issues. • In comparison to trimming pumps by adding restrictions, VFD 's work by varying the "speed " of the motor to provide the desired flow rate. • VFD 's also reduce the power company "Demand Charges" -the surcharge paid by larger power customers. So you will pay less for the electricity property -wide. • This savings is applied to your entire electric bill, not just the swimming pool or spa portion. • During normal operations, some pumps can be operated at 80% of peak capacity due to more efficient piping runs, and/or oversized pumps. ✓ During this time period the electrical consumption would be .8 x .8 x .8 or 51.2% of normal power. • During off-peak operations, some pumps could be operated at 50% of peak capacity while still circulating, filtering, and heating. ✓ During this time period the electrical consumption would be .5 x.5 x.5 or 12.5% of normal power. VFD Information (Commercial Aquatic Services, Inc., Watermark Energy Reduction) (http://www.swimcas.com/) provides information on cost savings using VFDs: Variable Frequency Drives at County Pools: Audit Criteria 117 We reduce the high energy consumption of pool filtration systems by controlling water flow using VFD, timer/controller, and electrical bypass system. A simple 20% reduction to water flow will yield more than 50% in electrical savings. Your system does not need to run at 100% capacity all the time. By utilizing proven and reliable technology to vastly improve existing motor/pump/filter system efficiency, while maintaining the highest water quality, you can reduce electric cost by 66% to 33%. Case study I Southern California High School Competition Pool: 486,000 Gallons Before the VFD was installed, the pool was warm, clean and clear with excellent water quality. Cost to run the motors: $29,381 per year. After the VFD was installed, the pool was warm, clean and clear with excellent water quality. Cost to run the motors: $11,160 per year. Electric bill reduced by 62% Before VFD installation: After VFD installation: The 40HP (25.8KW) The same motor now runs at motor ran at 100% 11.6 KW for 16 hrs and i.e., 24 hrs day. 6.2 KW for 8 hrs every day, all 365 days year. = 226,008 year. = 85,848 KWH/year KWH/year (13 cents per KWH) = $29,381/ year (13 cents per KWH) = $11,160/ year Resulting in an annual saving of $18,221 With power utility incentive, payback was less than months! Case study II Foothills YMCA: 128,000 Gal pool, 10HP motor, Power use before VFD system: 87,796 KWH, power use after VFD system: 32,149 KWH. Total annual savings: $6,844 with 63% energy reduction. Case study III Cal State University Pool: 287,000 Gal pool, power use before VFD system: 155,490 KWH, power use after VFD system: 82,004 KWH. Total annual savings: $9,553 with 47% energy reduction. Case study IV Beach City Fitness Pool: 787,000 Gal competition pool, power use before VFD system: 346,896 KWH, power use after VFD system: 209,418. Total annual savings: $27,222 with 40% energy reduction. Variable Frequency Drives at County Pools: Audit Criteria 118 Appendix B: Detailed Pool Electricity Costs Below is the detailed information for each of the three County -owned pools with VFDs: • Kawamoto Swim Stadium Prior to installing the VFD, from March to June 2006, electricity cost for four months totaled $35,664 or an average per month of $8,916. After VFD installed, electricity cost for four-month total was $13,116 or an average per month of $3,279. The difference between the per month averages was $5,637 for a 63 percent decrease in electricity. This substantial decrease is due, in part, to the fact that the pool is covered and not as exposed to the elements. $10,000.00 $9,000.00 $8,000.00 $7,000.00 $6,000.00 $5,000.00 $4,000.00 $3,000.00 $2,000.00 $1,000.00 $0.00 KAWAMOTO SWIM STADIUM Mar'06 Apr'06 May'06 lune'06 Sept'07 OWN Nov'07 Dec'07 Kawamoto Swim Stadium electricity cost before and after VFD. VFD in use from: September 2007 to December 2007 (first four months) Source: County of Hawai"i P&R - Aquatics. • Laupahoehoe Swimming Pool Prior to installing the VFD, from May to August 2008, electricity cost for four months totaled $14,197 or an average per month of $3,549. After the VFD installed, electricity cost for four-month total was $8,169 or an average per month of $2,042. The difference between the per month averages was $1,507 for a 42 percent decrease in electricity cost. Variable Frequency Drives at County Pools: Detailed Pool Electricity Costs 119 $4,000.00 $3,500.00 $3,000.00 $2,500.00 $2,000.00 $1,500.00 $1,000.00 $500.00 $0.00 LAUPAHOEHOE SWIMMING POOL May'08 lune'08 luly'08 Aug'08 May'09 lune'09 luly'09 Aug'09 Laupahoehoe Swimming Pool electricity cost before and after VFD. VFD in use from: May 2009 to August 2009 (first four months) Source: County of Hawaii P&R - Aquatics. • Pahoa Community Aquatic Center (PCAC) Prior to installing from February to May 2013, the electricity cost for four months was $37,005 or an average of $9,251 and after installation was $28,594 or an average of $7,148. The difference between both per month averages was $2,103 for a decrease of 23 percent in electricity cost. $12,000.00 $10,000.00 $8,000.00 $6,000.00 $4,000.00 $2,000.00 $0.00 PAHOA COMMNITY AQUATIC CENTER Feb'13 Mar'13 Apr'13 May'13 Sept'13 Oct'13 Nov'13 Dec'13 Pahoa Community Aquatic Center electricity cost before and after VFD. VFD in use from: September 2013 to December 2013 (first four months) Source: County of Hawaii P&R - Aquatics. Variable Frequency Drives at County Pools: Detailed Pool Electricity Costs 120