1. CATEE PRESENTATION– DECEMBER 18, 2013 DIANA D. GLAWE, PHD, PE, LEED AP ENGINEERING SCIENCE DEPARTMENT COLLECTING & USING CONDENSATE ON SITE

2. ENERGY ESTIMATES FOR SAN ANTONIO Extraction, processing, and distribution of potable water 1,939 KWh per million gallons Wastewater Treatment 2,232 kWh per million gallons (Source: Barker, Bill. 2010. “Energy Consumption Associated with Water.” Environmental Policy Office City of San Antonio.) 1 million gallons 4,171 kWh

3. CARBON FOOTPRINT ESTIMATES FOR SAN ANTONIO 6.8956 x 10-4 metric tons CO 2 produced per kWh * 4,171 kWh per million gallons potable water (Source: Environmental Protection Agency, Emissions and Generations Resource Integrated Database. ) 1 million gallons 2.84 metric tons

4. ENERGY WATER NEXUS Saving water saves energy Saving energy reduces carbon footprint (It works the other way around too…… saving energy saves water)

5. ON SITE WATER SOURCES Condensate Rainwater Cooling tower blowdown Reverse osmosis wastewater Gray water Etc.

6. CONDENSATE Water that collects on a cool surface because the temperature of the surface is below the point at which moisture in the air forms liquid droplets (i.e. dew point)

7. AIR HANDLING UNIT (AHU) (Source: San Antonio Condensate Collection and Use Manual for Commercial Buildings. Pending publication)

8. HOW MUCH CONDENSATE?

9. Example: 154,440 sq ft (727 ton) applied engineering and technology building measured condensate with predictions (747,290 gallons/yr) (Source: San Antonio Condensate Collection and Use Manual for Commercial Buildings. Pending publication) AWE Bryant & Ahmed SAWS

10. CONDENSATE WATER QUALITY? (Source: EPA WaterSense at Work. EPA 832-F-12-034)

11. CONDENSATE WATER QUALITY - METALS Condensate is slightly acidic Metals picked up along the flow path (ppm) Cooling coils Drain pan Drainage pipe Reservoirs/Tank Pumps Fixtures

12. CONDENSATE WATER QUALITY - MICROORGANISMS Legionella bacterium is primary concern for condensate use if aerosol is possible Comingling with other water sources adds microorganism possibilities No fecal matter expected in condensate alone

13. CONDENSATE APPLICATIONS Cooling tower Irrigation Car washing Water features Process water Toilet flushing

14. CONDENSATE (ALONE) APPLICATIONS Cooling tower make-up water is BEST application Low initial cost Easy implementation Cool and pure water a plus Low maintenance Example: Building producing 224,511 gallons per year. Cost to install retrofit system for cooling tower makeup water was $2,272 materials (pipes and pumps) plus $750 labor. SAWS rebate 50%. Incremental investment $1,511. Payback period 16 months. No water treatment beyond that already existing for cooling tower water. No overflow and no storage requirements. Maintain air seal and pump (if applicable). (Source: San Antonio Condensate Collection and Use Manual for Commercial Buildings. Pending publication)

15. TREATMENT TRAIN WHEN COMMINGLED Depends on reclaimed water source(s) Depends on reclaimed water application (Source: Adapted from Mechell et. al, Rainwater Harvesting: System Planning. 2010)

16. EFFECTIVE DESIGN – DRAIN LINE AIR SEAL (Source: San Antonio Condensate Collection and Use Manual for Commercial Buildings. Pending publication)

17. STANDARD P-TRAP Isolates air handling unit Minimizes pipe wet time Maintenance access point Trap configurations Draw-thru trap Blow-thru trap Standard traps incur High maintenance High failure rate (Source: Brusha, Ronald F. “Condensate Traps for Cooling Coils.” HPAC Engineering, Oct 2001)

18. ALTERNATIVES TO STANDARD P-TRAP P-trap with additions Condensate pump in drain pan Pneumatic air seal* P-trap (Source: San Antonio Condensate Collection and Use Manual for Commercial Buildings. Pending publication) * Patented by Trent Technologies, Inc. (CostGard)

19. EFFECTIVE DESIGN AND OPERATION– AUTOMATED MONITORING Drip pan overflow alarm Condensate meter data collection Make-up water meter data collection Water quality sensors in treatment train Make it difficult for system failures to go unnoticed

20. OPERATION AND MAINTENANCE - SCHEDULED MAINTENANCE PROGRAM Start with commissioning during installation! AHU: air filter, cooling coils, drain pan Drain seal Piping, pumps, and valves Storage Tank: overflow and makeup water control Backflow valve inspection Water treatment filters, lamps, etc. Water quality tests

21. CONDENSATE ON SITE USE Reduces city’s energy use Reduces city’s carbon footprint Potential quick return on investment for facility Potential to alleviate drought restrictions on site

22. QUESTIONS Diana D. Glawe, PhD, PE, LEED AP Associate Professor Trinity University San Antonio, TX 78209 dglawe@trinity.edu 210-999-7515