Lehigh University:Geothermal Heating and Cooling

Project Overview

Purpose• Feasibility study for application of geothermal heating and cooling at Lehigh University

Target• Assess environmental variables on all three LU campuses`• Determine “best fit” system for each campus• Perform basic cost analysis for viable system

Result• Goodman Campus: Greatest feasibility for application and success• Asa Packer Campus: Lacks adequate room for conventional installation, alternative systems “may work”• Mountain Top Campus: Not suitable for technology application

Asa Packer Campus SystemsAsa Packer Campus Details• Heating and Cooling for campus provided by Central Steam and Chilled Water plant• Data unavailable on individual building heating/cooling loads• Estimation based on number of buildings and total provided cooling load • Estimated load requirement: 350 tons • Calculated Energy Cost per Year: N/A (lack of data)

Asa Packer System #1 • 350 ton Vertical Bore Closed-Loop System • 175 boreholes @ 350 feet deep, spaced 20 feet • 2 locations meet size requirements (not shown)Breakdown • Estimated GHP System Cost: $504,000 (includes drilling, labor, system components)Conclusion • Asa Packer Closed-Loop System: “Not Feasible” o Massive borefield makes closed-loop installation unreasonable (campus disruption during installation and high probability for underground utilities/setback distance requirements) o High cost of system unlikely to offset current system costs

Asa Packer System #2 • 350 ton Indirect Open-Loop System • 2 Production Wells @ +400 feet deep, 2 Injection Wells @ +400 feet deep • Requires at least 350 gpm water flow • Placement Flexible (depends upon groundwater production)Breakdown • Estimated GHP System Cost: $203,000 (includes production/injection well drilling, well testing, system components, 15% contingency factor)Conclusion • Asa Packer Indirect Open-Loop System: “May Work” o Improved cost over closed-loop system o Historical data shows potential for high yield wells o Open-Loop system requires significantly increased maintenance o Poor Groundwater Quality likely to impact system performance

Asa Packer Hybrid System • 210 ton Hybrid System w/ 140 ton Air-Source Cooling Tower • Assuming a 10:6 cooling to heating ratio • 105 boreholes @ 350 feet deep w/ spaced 20 feet • 3 locations meet size requirements (not shown)Breakdown • Estimated GHP System Cost: $378,000 (includes drilling, labor, system components, cooling tower components, tower pad, and 15% contingency)Conclusion • Asa Packer Closed-Loop Hybrid System: “May Work” o Improved cost over closed-loop system o Campus Square parking lot: Excellent system location o Cooling tower requires increased maintenance

System Cost Comparison

Goodman Campus System

Goodman Campus System • 100 ton Vertical Bore Close-Loop System • 49 boreholes @ 360 feet deep, spaced 20 feet • 3 feasible borefield locations (Fig.)System Breakdown • Estimated GHP System Cost: $144,000 (Includes drilling, labor, system components) • Estimated Operational GHP Operational Cost per Year: $28,000 • Minimum Yearly Operational Savings: $8,750 (calculated current energy costs does not include cost of maintenance) • Result: Potential Return on Investment within 20 year system life-spanConclusion • Goodman Campus Closed-Loop System: “Feasible” o Low system cost o Reduced Energy Consumption o Flexible installation location o 17 year payback period

Goodman Campus Details• Goodman Campus application focused specifically on the Varsity Center Building; it is occupied year round (Outlined in Fig.)• Varsity Center is heated via natural gas and partially cooled via electric air-sourced refrigeration unit• Estimations include cooling applied to entire building *(cost of additional ventilation equipment and labor not included)Varsity Center Breakdown • Size: 35,000 sq. ft. • Current Heating Load: 60 tons • Current Cooling Load: 20 tons (partial building) • Estimated Energy Cost per Year: $31,350 • Theoretical Required Cooling Load: 100 tons (entire building) • Estimated Current Energy Cost per Year w/ 100 ton conventional cooling: $36,750

Figure: Aerial view of Goodman Campus proposed system locations (Source: GoogleEarth)

$600

$0 ASA #1(closed loop)

GOODMAN(closed loop)

ASA HYBRIDASA #2(open loop)

$504,000

$144,000

$378,000

$203,000

$500

$400

$300

$200

$100

By: Michael MahalSponsor: Haley-AldrichEnergy Systems Engineering 2010