Trane Sales Webinar Central Geothermal Systems - ASHRAE

1 Trane Sales Webinar Central Geothermal Systems A System Trane Sales Webinar Lee Cline Senior Principal Systems Engineer Trane La Crosse, WI 3 Agenda Overview Multiple Chiller/ Heater Bi-directional Cascade Single Chiller/Heater Configurations Water-to-Water heat Pump Configurations A Few Lessons Additional Resources Q&A 3 5 Distributed Geothermal System heat pumps water pumps vertical-loop ground heat exchanger (borefield) WSHPs Dedicated outdoor air units Optional fluid cooler Water pumps Geo heat exchanger 5 Central Geothermal System Chillers provide heating and cooling Ground couple for an efficiency boost Central air handlers VAV terminals Water pumps Auxiliary boilers Fluid or dry cooler Air handlers chiller/heaters Geothermal loop (borefield) VAV boxes 6 7 Central Geothermal Customer Benefits Compared to Distributed Premium efficiency (LEED EA Credit #1)

2 Efficient Central equipment Bi-directional cascading VAV Air economizing Better heat recovery management Easy to maintain Central equipment, few cooling units Uses equipment rooms, no access to occupied space required Simpler coil condensate collection 7 8 Central Geothermal Customer Benefits Compared to Distributed Low space noise (ASA ) Fans and compressors away from occupied space Noise paths can be more easily attenuated Good IAQ Many filtration options available (LEED EQ 5 MERV 13) Easier to deliver 30% more outdoor air (LEED EQ 2) 8 10 Vertical Markets Education Primary and secondary Colleges and universities Government Federal sector State and county level Long-term owners Accept extended payback periods Interested in embracing green technologies Usually have space for a borefield 11 Incentives Utility Reimbursement Tax (if private) 12 Central Geothermal System Types System Type Capacity Range Target Market Single chiller/heater Systems (based on typical industry units) K / 12 Schools Simpler / Smaller Premium Efficiency cascading multi-chiller/heater Systems (based on typical industry units)

3 High School / Secondary Ed > 36,000 sq. ft Super Premium Efficiency Water-to-water heat pump system (based on typical industry units) Small Building Large Volume 80% of Buildings < 25,000 sq ft Premium Efficiency 150-1500 tons 70-250 tons 5-200 tons 13 Agenda Single Chiller-Heater Central Geothermal Systems Four-pipe distribution system configuration Two-pipe distribution system configuration Multiple Unit Cascading Systems Water-to-Water heat Pump Based Systems 14 Central Geothermal Systems Single Chiller-Heater Allow screw compressor chiller-heater based CGS Systems down to 70-75 tons Simple configurations Simpler operation Two basic distribution configurations.

4 4-pipe simultaneous heating/cooling 2-pipe changeover heating/cooling 15 P-GS 4-pipe distribution / Constant flow (3-way control valves) aux heat cond evap CHR-1 Chiller/Heater P-CH P-HT heating loads cooling loads Single Chiller-Heater CGS to ground source from ground source VAL-1 / VGS 16 P-GS aux heat cond evap CHR-1 Chiller/Heater VAL-1 / VGS P-CH P-HT heating loads cooling loads Standard chilled water system maybe constant flow, primary/secondary or variable primary flow Single Chiller-Heater CGS 4-pipe distribution / Constant flow (3-way control valves) to ground source from ground source 17 P-GS aux heat cond evap CHR-1 Chiller/Heater VAL-1 / VGS P-CH P-HT heating loads cooling loads Heating water system will likely be constant flow or primary/secondary 4-pipe distribution / Constant Flow (3-way control valves)

5 Single Chiller-Heater CGS to ground source from ground source 18 aux heat heating water by-pass chilled water by-pass VAL-1 / VGS P-CH P-CD heating loads cooling loads cond evap CHR-1 Chiller/Heater VAL-1 / VGS P-HT Primary/secondary heating water system - for expanded distribution delta T and variable flow 4-pipe distribution / Decoupled pumping Single Chiller-Heater CGS to ground source from ground source P-GS 19 aux heat cond evap CHR-1 Chiller/Heater VAL-1 / VGS P-CH P-HT heating loads cooling loads Ground-source loop should be variable flow for controllability and pumping efficiency 4-pipe distribution / 3-way control valves Single Chiller-Heater CGS to ground source from ground source P-GS 20 Central Geothermal System Options Auxiliary heating NOT OPTIONAL for single unit Systems Auxiliary heat rejection Auxiliary cooling Contingency cooling connections 21 P-GS Contingency Cooling Connections aux ht reject Central Geothermal System Options aux heat cooling loads cond evap aux cooling heating loads Chiller/Heater P-CH P-HT to ground source from ground source VAL-1 / VGS Single Chiller/Heater Central Geothermal Systems 23 2-pipe distribution / Constant Flow

6 (3-way control valves) Single Chiller-Heater CGS V1 cond evap Chiller/ Heater V2 auxiliary heat V3 building loads to ground source from ground source P-GS P-DS V4 24 Single Chiller-Heater CGS 2-pipe distribution / Constant Flow (3-way control valves) Cooling only mode V1 cond evap Chiller/ Heater V2 auxiliary heat V3 building loads to ground source from ground source P-GS P-DS V4 Chilled water distribution will likely be constant flow or primary/secondary 25 Single Chiller-Heater CGS 2-pipe distribution / Constant Flow (3-way control valves) Cooling only mode V1 cond evap Chiller/ Heater V2 auxiliary heat V3 building loads to ground source from ground source P-GS P-DS V4 Ground-source loop providing cool water to the chiller/heater condenser 26 2-pipe distribution / Constant Flow (3-way control valves) Single Chiller-Heater CGS Heating only mode V1 cond evap Chiller/ Heater V2 auxiliary heat V3 building loads to ground source from ground source P-GS P-DS V4 Heating water distribution will likely be constant flow or primary/secondary 27 Single Chiller-Heater CGS 2-pipe distribution / Constant Flow (3-way control valves)

7 Heating only mode V1 cond evap Chiller/ Heater V2 auxiliary heat V3 building loads to ground source from ground source P-GS P-DS V4 Ground-source loop providing warm water to the chiller/heater evaporator Multi-Chiller/Heater Cascading Central Geothermal Systems 29 cooling load On Cool PLc PC PLe M M M A cond evap On heat M PH B cond evap heating load Central Geothermal Systems Multi-Chiller/Heater Cascading VAL-2 / VEC VAL-3 / VCC M M VAL-1 / VGSC PB to ground source from ground source 30 Multi-Chiller/Heater Cascading Review Number of Chiller-Heaters 2-6 Units Nominal 80-250 ton unit capacity Actual 150-1500 ton plant size Operating conditions 38 leaving chilled water 140 leaving condenser water (lower is better) Not at the same time!

8 Cascading has the potential to increase plant efficiency The energy transfer loops increase plant controllability 31 PB VAL-2 / VEC VAL-3 / VCC M M VAL-1 / VGSC cooling load On Cool PLc PC PLe M M M A cond evap On heat M PH B cond evap heating load Multi-Chiller/Heater Cascading Introduction to ground source from ground source 32 VAL-2 / VEC VAL-3 / VCC M M VAL-1 / VGSC Cooling system cooling load On Cool PLc PC PLe M M M A cond evap On heat M PH B cond evap heating load Multi-Chiller/Heater Cascading Introduction Standard Chilled Water System may be: constant flow primary/secondary or variable primary flow to ground source from ground source PB 33 PB VAL-2 / VEC VAL-3 / VCC M M VAL-1 / VGSC Heating system cooling load On Cool PLc PC PLe M M M A cond evap On heat M PH B cond evap heating load Multi-Chiller/Heater Cascading Introduction Heating Water System will likely be constant flow or primary/secondary to ground source from ground source 34 VAL-2 / VEC VAL-3 / VCC M M VAL-1 / VGSC cooling load On Cool PLc PC PLe M M M A cond evap On heat M PH B cond evap heating load Ground-source loop Multi-Chiller/Heater Cascading Introduction

9 Ground-source loop should be variable flow for pumping efficiency to ground source from ground source PB 35 VAL-2 / VEC VAL-3 / VCC M M VAL-1 / VGSC cooling load On Cool PLc PC PLe M M M A cond evap On heat M PH B cond evap heating load Condenser Energy Transfer Loop Multi-Chiller/Heater Cascading Introduction Condenser Energy Transfer Loop brings cooling water to condenser from ground-source loop or heater evaporator to ground source from ground source PB 36 PB VAL-3 / VCC cooling load On Cool PLc PC PLe M M M A cond evap On heat M PH B cond evap heating load Evaporator Energy Transfer Loop Multi-Chiller/Heater Cascading Introduction VAL-2 / VEC M M VAL-1 / VGSC Evaporator Energy Transfer Loop brings warm water to evaporator from ground-source loop or chiller condenser to ground source from ground source 37 PB VAL-2 / VEC VAL-3 / VCC M M VAL-1 / VGSC cooling load On Cool PLc PC PLe M M M A cond evap On heat M PH B cond evap heating load Single Chiller-Heater Operation Multiple chiller-heater Systems can and will provide simultaneous cooling and heating with one unit.

10 Multi-Chiller/Heater Cascading Introduction to ground source from ground source 38 Central Geothermal Systems Water To Water heat Pump WWHP Simple piping - dedica