1. RETROCOMMISSIONING AIR HANDLING SYSTEMS In The College of Applied Science and Technology (CAST), Building 70 Critical Design Review Presentation May 13th 2005Project 05306

2. Team Members Mechanical Engineers Erin Colquitt (Team Leader) Joe DiSanto (Chief Engineer) Jason Bolton (HVAC Specialist) Dan Esposito (HVAC Specialist) Electrical Engineer Jimmy Liang (Electrical Specialist)

3. Overview Background AHU System Components & Testing Engineering Analysis Retrofit Solutions

4. Background Commissioning Retrocommissioning Reviews of existing system against design specifications Extends lifetime of components Analyzes efficiency for comparison Minimize energy waste

5. Overview of SD I Needs Assessment Concept Development Feasibility Develop Initial Test Plan Set Up Analysis

6. Project Goals - Senior Design 2 Complete testing with AHU1 Corrections of test checklists Create Excel program for data analysis Meet with sponsor to verify the checklists and performances of AHU1 Develop retrofit solutions

8. Instrumentation Digital Multimeter Tachometer Thermometer Probes Digital Micromanometer Wireless Laptop Web Control

10. Testing General AHU Test Sensor Verification Control Response Supply/Return Fans Heating/Cooling Coils Economizer

11. General AHU Test

12. Fan Performance Test

13. Coil Performance Test

14. Economizer Performance Test

15. Thermodynamic Analysis Mass Balance Energy Balance Exergy Analysis First and Second Law Efficiencies

16. Assumptions Control Volume is around the AHU Mass flow in and out of CV Outside air Hot water Cold water Exhaust air Supply air Work into fans Steady State Air is an ideal gas Constant specific heats Incompressible flow of air No heat transfer out of CV Ignore potential and kinetic energy of air

17. Exergy Potential for energy use Steady state exergy balance Specific Flow Exergy (e f )

18. Economizer

19. Economizer Analysis Mass Balance Energy Balance – check adiabatic assumption 2 nd Law Efficiency

20. Heating Coil Energy Balance 2 nd Law Efficiency Coil Effectiveness

21. Fan Performance 1 st Law Fan Efficiency 2 nd Law Efficiency

22. Overall System

23. Analysis Results Exergy Destroyed, E d (Btu/min) Exergetic Efficiency,  Set PointDesign123123 Supply Fan2152.8632.7748.7897.658.8%62.0%64.1% Return Fan1186.9184.9240.0271.555.7%41.5%42.3% Heating Coil3735.2229.7230.51438.9---- Set PointDesign123 Supply Fan70.3%60.6%63.7%65.5% Return Fan47.5%53.6%40.0%40.7% Set PointDesign123 Coil Effectiveness20.7%51.0%38.3%33.6%

24. Findings Reduced Damper Range Dirty/Clogged Airflow Sensors Reduced Static Pressure Set Point Maintained Occupant Comfort

25. Cost Savings Assumptions RIT receives a rate of electricity at 7.2cents/KWh Two Air Handling Units are connected together The new static pressure can be maintained for 50% of the year Sample Calculation for reducing from 1.5 to 1 in WC Total Estimated Savings = $2,445.50/year

26. Retrofit Solutions Fix Dampers to operate over full range Routinely clean WebCtrl sensors Reduce Duct Static Pressure To 1” WC

27. Feedback/Questions ?