LA Fitness, West Oaks

1. LA Fitness, West Oaks Houston, Texas David Melfi Mechanical Option The Pennsylvania State University Department of Architectural Engineering Senior Thesis Spring 2006

2. Presentation Outline • Building Description • Goals & Metrics • Design Parameters • Air Side Alternatives • Hot Water Alternatives • Discussion of Original Design • Desiccant Dehumidification • Recommendation

3. Building Description Building Information • 45,000 ft2 • Exercise Facility • Houston, TX • Construction Started: 5/9/05 Finished: 12/09/05 • Cost of Building: $4.5 Million Primary Project Teams • Owner: LA Fitness International, LLC • General Contractor: Ridgemont Construction • Construction Manager: LA Fitness International, LLC • Architects: Heights Venture Architects, LLP • MEP Engineers Advanced Technologies, Inc. • Structural Engineers: BGA Engineers • Civil Engineers: Cobb Fendley & Associcates • Interior Designers: Senninger Walker Architects

4. Presentation Outline • Building Description • Goals & Metrics • Design Parameters • Air Side Alternatives • Hot Water Alternatives • Discussion of Original Design • Desiccant Dehumidification • Recommendation

5. Goals & Metrics Design Goals • Energy Reduction Compared to Original Design • Lower Environmental Impact • Economic Feasibility • Gain Practical Experience Designing and Integrating Mechanical Systems Metrics • Annual Energy Consumption • Emissions • Economics Analysis

6. Presentation Outline • Building Description • Goals & Metrics • Design Parameters • Air Side Alternatives • Hot Water Alternatives • Discussion of Original Design • Desiccant Dehumidification • Recommendation

7. Design Parameters • Ventilation Requirements • Standard 62.1-2004 Reevaluation • Cooling & Heating Loads • Lighting Loads • Building Envelope • Humidity Control • Critical Zones

8. Ventilation Design Parameters ASHRAE Standard 62.1-2004 Requirements:

9. Design Parameters Critical Zones • Indoor Pool & Locker Room Spaces • Relatively Negative Pressure • 4-6 Air Changes/Hour • 800F & 55% Relative Humidity • Pool Water Temperature: 820F • Latent Load From Pool 102,950 Btu/hr

10. Presentation Outline • Building Description • Goals & Metrics • Design Parameters • Air Side Alternatives • Hot Water Alternatives • Discussion of Original Design • Desiccant Dehumidification • Recommendation

11. Air Side Alternatives Original Design • Cooling Loads Met by 13 Packaged Rooftop Units • Constant Volume • Primarily Single Zone • Economic Advantage Over Other Equipment • OA Rebalance and Redistribution Is Necessary

12. Air Side Alternatives Hydronic System – Water Cooled Chiller • Screw Compressor • 200 ton Chiller Performing at 0.66 kW/ton • Cooling Tower Necessary • 4 AHU Needed to Condition the Air • Higher Associated Maintenance Cost/Year

13. Air Side Alternatives Hydronic System – Air Cooled Chiller • Screw Compressor • 200 ton Chiller performing at 1.22 kW/ton • Less Maintenance Cost Compared to WC Chiller • Less Efficient Performance • Relatively Good Part Load Performance

14. Air Side Alternatives Discussion of Energy Sources • Hydronic Systems • Lower Annual Energy Consumption? No • Lower Annual Energy Costs? No

15. Presentation Outline • Building Description • Goals & Metrics • Design Parameters • Air Side Alternatives • Hot Water Alternatives • Discussion of Original Design • Desiccant Dehumidification • Recommendation

16. Hot Water Alternatives Original Water Heating • Three Natural Gas Fired Water Heaters • 1200F Water • 300 MBH • 100 gal of Storage Each Solar Water Heating • Three Types Commercially Available • Unglazed Flat Plate Collector • Glazed Flat Plate Collector • Evacuated Tube Collector • Model Established Using RETScreen Solar Water Heating Program

17. Hot Water Alternatives Solar Water Heating • Results of Analysis: • Use Glazed Flat Plate Collector In Final Design • Issues of Solar Reliability • Use Existing Water Heaters as Storage Tanks • Structural Analysis Necessary for Flat Roof

18. Presentation Outline • Building Description • Goals & Metrics • Design Parameters • Air Side Alternatives • Hot Water Alternatives • Discussion of Original Design • Desiccant Dehumidification • Recommendation

19. Discussion of Original Design Original Rooftop Unit Design • Pros: • Lowest annual primary energy • Lowest emissions • Lowest first cost • Cons: • High load on DX coil • RTU-1 & RTU-2 lose humidity control • Wasteful to cool & dehumidify air  reheat the air • cfm/ton limitations

20. Discussion of Original Design • Original Rooftop Unit Design • RTU-1 & RTU-2

21. Discussion of Original Design • Original Rooftop Unit Design • Reheat & Humidity Sensor Option

22. Discussion of Original Design Is there a better way to meet the air side loads while satisfying the design criteria? Up until this point in the analysis, the focus of study was to find a completely new base system that could better meet the airside loads. Paradigm shift: Instead of finding better alternative from scratch the question became: How can the existing “good enough” equipment be modified to have better performance for this site?

23. Presentation Outline • Building Description • Goals & Metrics • Design Parameters • Air Side Alternatives • Hot Water Alternatives • Discussion of Original Design • Desiccant Dehumidification • Recommendation

24. Desiccant Dehumidification • Another means to control humidity • Low surface vapor pressure attracts moisture from air • System can be configured in a rotating “honeycomb” wheel arrangement • Sensible Heat Gain from Process • Active or Passive? • Decision Made to Use Active Desiccant • Sensible Wheel Also Necessary

25. Desiccant Dehumidification Active Desiccant Configuration with Sensible Wheel • Air processed by desiccant leaves very hot and dry • Sensible wheel used to restore a hot, dry temperature • Air heater used to reactivate desiccant for further use • Result of process: significant reduction of latent load

26. Desiccant Dehumidification • Psychrometric Analysis of Wheels

27. Presentation Outline • Building Description • Goals & Metrics • Design Parameters • Air Side Alternatives • Hot Water Alternatives • Discussion of Original Design • Desiccant Dehumidification • Recommendation

28. Recommendation Initial idea to modify each unit: • Requires 26 wheels for the 13 units • This idea was too expensive and labor intensive Rather: • Use 1 central dehumidification station to handle all of the OA for the building • Duct the OA from this central unit to the OA intakes of the 13 originally scheduled units

29. Recommendation

30. Recommendation Economic Analysis Energy Consumed/Year Includes New System Components: • Motor energy for wheels • Fan energy Payback Period Analysis • Conservative Payback Period: 11 Years • Interest Used: 6% • Natural Gas Escalation Rate: 3% • Modified Payback Period: 8.5 Years • Interest Used: 6% • Natural Gas Escalation Rate: 8%

31. Many Thanks To... • Advanced Technologies, Inc • Penn State AE Mechanical Faculty • Dr. James D. Freihaut • Mike Prinkey • Tony Daniels • Karen Schulte • My Family • Friends and Colleagues

32. Questions

33. Integration of Design • The entire building requires 17,630 cfm of OA to meet the corrected Standard 62.1 requirements • Using an Active Desiccant Configuration, 6000 cfm of counterflow air is necessary • EF-5 from the original design was a perfect fit (6,300 cfm) • This exhaust air stream is centrally located near 7 of the 13 rooftop units

34. Energy Rates • Energy Rates Natural Gas Rates • May 2005 Texas Commercial Rate: $8.67/MMBtu • Dec 2005 Texas Commercial Rate: $14.68/MMBtu Electric Rates • May 2005 Texas Commercial Rate: $22.86/MMBtu • Dec 2005 Texas Commercial Rate: $23.45/MMBtu