Design, Analysis & Cost Development of a 220 Ton Geothermal HVAC System Albert A. Koenig, Ph.D. ARB/Geowell Systems

Presentation Outline L.E.E.D. Building Design (Silver) Goals Load Modeling/Simulation HVAC Distribution Technology Hydronic System Scheme Site Information Load Design Spec The Geowell TM SCW Technology Geowell TM String Deployment 220 Ton Geothermal Field Layout Installed Cost & Payback

Building Design Standard  Basis: ASHRAE/IESNA Standard for building energy efficiency/sustainability and Standard 62 for ventilation  Bldg. envelope & systems designed to maximize energy performance, based on – Computer simulation model (DOE-2, TRACE) – Identification & implementation of the most cost-effective energy efficiency measures – Quantification of performance vs. baseline bldg.  20% renewable energy credit: geothermal

Building Operating Expense

Building Interior Daylighting

DOE-2: Model Bldg. Hourly Energy Use

Silver L.E.E.D. Design Goal Targets: 280 KBTU/sqf =>180 KBTU/sqf annual energy use HVAC equipment: 250 tons => 180 tons Equipment: Innovative active chilled beam ceilings for integral room comfort using geothermal chilled water to provide 15°F ΔT (floor to ceiling) 73% efficient economizer with energy recovery wheel

Exposed Chilled Beam Technology Esp. Suited for Open Office Areas

Chilled Beam Bldg. Heat Transfer

Hydronic System Diagram

Building External HVAC Load: HDD/CDD

Building HVAC Design Spec 80,000 sqf office building (7 floors) 220 tons (365 sqf/ton) Building Load: – External Load: 92 tons – Internal Load: 128 tons (lighting, people, equipment & air transport)

Site Information  20 acres wooded area (NJ/NY)  Proximity to river for ground water recharge  Ample water well records in vicinity  Water 50-60’ from surface  Excellent hydrogeology for geothermal application

Rock Thermal Properties

Seasonal Heat Storage Measurement & 50’/ton

ARB/Geowell Technology A New Old Approach for Using Geothermal Water Wells for Building HVAC

Water Well Operation with Re-injection Wellbore Heat Transfer

Patented in-Well String Design for Fast Deployment & Maintenance

Impact of Polypipe Insulation on Wellbore Heat Transfer

Heat Transfer Benefit of Geowell TM : 4-Fold Improvement Over Closed Loops

The ARB/Geowell Technology Patented SCW technology that insure:  minimal geofield installed expense use of deep (nom. 1000’) wells to minimize footprint and the number of submersible pumps the entire 6” wellbore diameter and length are utilized in return water heat exchange minimal total drilled length to satisfy bldg. load specification fast installation of each well string minimal field installation time (pre-fab ext. plumbing)  minimal operating expense minimal parasitic power utilization by employing a control algorithm that activates on those well pumps that are needed to satisfy the load well strings designed for ease of pump replacement

Fast In-Well Deployment

Lower installed cost ($1300 vs. $2300 per ton) Smaller wellfield footprint (20% of closed loop) Minimal parasitics: well row operational selectivity Wellfield design using minimal number of pumps Pre-fab plumbing kits to min. field installation expense & insure best practices Fast installation of in-well components Geowell Advantages

Applications 220 Ton Geothermal Field Layout

220 Ton Geowell Field Layout

220 Ton Design Specification Based on drilling to a nom. depth of 800’ 20 water wells, operated 4 rows x 5 wells per row, or 5 x 4 Well-well spacing 30’ Footprint: ⅓ acre Installed cost: $211,800

Field Plumbing Schematic

Installed Cost Breakdown

Installed Cost & Payback Geowell Example: 220 ton bldg. load Installed loop (20 wells) price: $286,000 [Heat Pumps (220 tons total): $176,000] less State Rebate ($/ton): ? - $ 77,000 less Fed Tax deduction: - $ 48,000 Net Cost: $161,000 Annual Operating Savings:$ 22,850 Discounted Payback: 6 yrs

Discounted Payback Analysis

Federal Tax Incentives EPAct 2005 for Commercial Bldgs. Tax deduction of up to $1.80/sqf for qualifying property (e.g.$144,000 for a 80,000 sqf bldg.) Split three parts: ⅓ each for envelope, lighting and HVAC Fully qualifying property must show (in a simulation) 50% energy & power savings over a reference bldg. that meets minimum Standard

State Rebate Program Geothermal GSHP Installations PA offers only Energy Harvest grant opportunities and Sustainable Development Fund (SDF) loan pool (7-9%) + PECO ($800 installation rebate) NY: $ /ton under LIPA NJ: $370/ton DE: $600/ton capped at $25,000