Technology and Engineering Development (TED) Building Thomas Jefferson National Accelerator Facility Newport News, VA David Blum | Mechanical Option Dustin Eplee | Adviser Architectural Engineering | The Pennsylvania State University Presentation Overview Project Background Site, use, and architecture Existing Mechanical System Air system, hydronic system, geothermal system Horizontal Directional Drilling (Depth 1) An alternative geothermal solution Radiant Floor Slab Cooling (Depth 2) An exploration of slab thermal capacity Construction Schedules and Costs for Alternatives (Breadth 1) Presented after each depth Final Conclusions

General Building Information Architecture Design and Use Size: 70,000 SF Stories Above Grade:Two Project Team Owner:Jefferson Lab CMGC: Mortenson Construction A/E: EwingCole Cost Consultant: Crawford Consulting Services, Inc Dates of Construction: 8/4/2010 – 9/30/2011 Cost: $16 million Project Delivery Method: Design-Bid-Build Site 1 st Floor Research Workspaces Highbay Area 2 nd Floor Offices, Conference, and Administration Health Club, Break Room Main Mechanical Room Thomas Jefferson National Accelerator Facility Newport News, VA

Hydronic System Hybrid Condenser SystemAir System Vertical Bore Geothermal 3 Fields 192 Wells 300 ft Depth Full Heating Load 72 % Cooling Load Closed Circuit Cooler 28% Cooling Load Variable Air Volume with Terminal Reheat AHU 1: 32,000 CFM serves 1 st Floor and Highbay AHU 2: 32,000 CFM, 2 nd Floor Fan Powered Boxes serve perimeter zones VAV Boxes serve interior zones Outdoor Air Pre-Conditioning OAU 1: 7,500 CFM serves AHU 1 OAU 2: 6,800 CFM serves AHU 2 Total Energy Wheel exchanges latent and sensible heat with exhaust 12 Central Water to Water Heat Pumps Chilled Water:42 F Supply, 50 F Return Cond. Water:85 F Entering, 95 F Leaving Hot Water:120 F Supply, 110 F Return Cond. Water:55 F Entering, 45 F Leaving EER:14 10 Chilled Water, 6 Hot Water Boiler Backup heat source

Existing and Proposed Geothermal Fields Field TypeDepth 1: Full Load Geothermal Design Goals Add field to meet full cooling load: 67 additional tons Minimally invade tree line (per owner) Compare energy use and first costs to current hybrid condenser system Horizontal Trench 2500 ft 2 /ton and $600 to $800 / ft 2 167,500 ft 2 required is too large Vertical Bore 250 ft 2 /ton and $900 to $1100 / ft 2 16,750 ft 2 required eliminates trees Horizontal Directional Drilling Horizontal bores under obstacles Up to 600 ft long and 45 ft deep Stacked vertically in ground 176,000 ft 2 Existing Proposed

Bores Total Length:21441 ft Length per Bore:450 ft No. Bores:48 No. Rows:16, 3 stacks (15 ft, 30 ft, 45 ft) Spacing:15 ft Diameter:5” Pipe:1” HDPE Grout:Bentonite (k = 1.0 hr-ft-F/Btu) Pumps 1100 GPM VFD Layout Annual Energy Use Closed Circuit Cooler (1599 hrs):89,429 kWh Total Current HVAC:646,138 kWh Total Proposed HVAC:556,709 kWh Savings:13.8% Geothermal Design Energy and Operation Life Cycle Operational Savings:-$5,982/ yr Additional First Costs:$178,096 Simple Payback:30 years

HDD Geothermal Construction Cost Current Condenser:$756,074 Closed Circuit Cooler:$51,054 Vertical Bore Field:$687,936 Pumps:$17,084 Proposed Condenser:$934,170 HDD Field:$229,150 Difference:+$178,096 (+7.3% HVAC Budget) Installation Process Budget and Schedule Impact Schedule Impact Field Installation and Equipment Mobilization: 62 Days (~12.5 Weeks)

Depth 2: Radiant Floor Cooling Slabs Goals Explore the capabilities of floor slab thermal storage Analyze cooling capacity and effects on air system Compare daily cooling energy use and power demand profile with current HVAC system Radiant Slab Implementation Radiant Slab Design Conditions 1 st Floor 2 nd Floor Floor Surface Temperature:68 F Indoor Air:78 F, 50% RH, 58 F DP 1 st Floor 5” NW Slab on Grade Covering:Conductive Concrete (ESD) 3 / 8 “ PEX Tubing Depth:4” Below Surface CHWS Temp:61 F 2 nd Floor 3 ¼” LW Elevated Slab on Metal Deck Covering:¼” Carpet 3 / 8 “ PEX Tubing Depth:1 ½” Below Surface CHWS Temp:55 F

Load and Energy Model Required Cooling Airflow Proposed Systems Excel Spreadsheet Model Adapted RSTM method Hourly slab temperature from heat balance Radiant Slab System Distribution Pump:187 GPM, 7.5 HP 3 Heat Pumps, EER:16 Slabs in series Parallel Air Systems AHU 1:16,825 CFM AHU 2:15,446 CFM CHW Distribution Pump:350 GPM, 15 HP 6 Heat Pumps, EER:14

Breadth: Radiant Floor Construction Daily Energy Use Daily Energy Use by Component Currently Designed SystemRadiant Slabs System Current Design 283 kW 3,725 kWh Radiant Slabs 205 kW 3,238 kWh Peak Demand: Total Usage: Savings 27.5% 13.1% Cost Current HVAC System:$2,450,000 AHUs:$372,290 Pumps:$12,336 Radiant Slab HVAC System:$2,613,000 (+6%) AHUs:$185,920 Pumps:$18,126 Radiant Floor:$319,625 Schedule Impact 26 weeks with one crew 2 weeks with Climate Mat

Final Conclusions Geothermal Systems Hybrid geothermal systems can reduce first costs while still reducing energy use Horizontal Directional Drilling offers ability to install geothermal fields with little land disturbance Radiant Floor Slabs Can be used to flatten demand profile Controllability becomes important because cooling effect is not instant

Acknowledgements A special thank you to the following people and parties that made this project possible: Jefferson Lab, TED Owner EwingCole, Architects, Engineers, and Interior Designers Eric Joesten, Director of Mechanical Engineering, EwingCole Kate Mondock, Mechanical Engineer, EwingCole Dustin Eplee, Thesis Adivsor Mentors on the Thesis Class Discussion Board