Geothermal H.V.A.C. Systems in High Performance Buildings

Transcription

1 Geothermal H.V.A.C. Systems in High Performance Buildings An Introduction to Geothermal Systems for Green Spaces By: Matt Williams, P.E., LEED AP Campbell & Associates, Inc.

2 The 3 Major Components to an Energy Efficient Building: HVAC Lighting Building Envelope

3 System Strategies: 1. HVAC Standard Systems: Packaged or Split System DX, Variable Air Volume, Heat Pumps or Gas High Performance Systems: Geothermal, Variable Refrigerant Volume (VRV), Ultra High Efficiency DX Equipment Energy Recovery Ventilators (ERV s) Demand Control Ventilation 2. Lighting 3. Building Envelope

4 System Strategies: 1. HVAC 2. Lighting High Efficiency Fixtures (T5, T5 HO s, LED s) Task Lighting Occupancy Sensors Natural Daylighting (Clerestories, Light Tubes, Light Shelves) Daylighting Controls 3. Building Envelope

5 System Strategies: 1. HVAC 2. Lighting 3. Building Envelope Roof R-Value, High Albedo Walls R-Value, Shading Glazing High Performance, Location, Glare Control

6 1. Fast Paybacks (1-3 years) Considerations: ERV s, Demand Control Ventilation Enhanced Glazing Occupancy Sensors for Lighting 2. Mid Range Paybacks (4-9 years) Geothermal, VRV Enhanced Insulation High Efficiency Lighting, Daylighting Controls Passive Solar Water Heating 3. Long Term Paybacks (10+ years) Active Solar Photovoltaics (can be quicker with incentives) Cisterns Geothermal

7 Geothermal Heat Pump Systems Types of Geothermal Systems Conventional Closed Loop -Vertical -Horizontal -Reservoir (Radiator or Coils) Hybrid Open Loop -Pump & Dump -Reinjection

8 What is Geothermal Hea<ng & Cooling? Ground source heat pumps are electrically powered systems that tap the stored energy of the greatest solar collector in existence: the earth. These systems use the earth's rela<vely constant temperature to provide hea<ng, cooling, and hot water for homes and commercial buildings. 8

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11 WATER-LOOP HEAT PUMP SYSTEM WSHP WSHP WSHP WSHP WSHP WSHP WSHP WSHP PUMP BOILER COOLING TOWER

12 WATER-LOOP HEAT PUMP SYSTEM WSHP WSHP WSHP WSHP WSHP WSHP WSHP WSHP PUMP BOILER COOLING TOWER

13 CONVENTIONAL GEOTHERMAL HEAT PUMP SYSTEM WSHP WSHP WSHP WSHP WSHP WSHP WSHP WSHP PUMP LOOP FIELD

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20 Stub Up Supply/Return Piping in Building 20

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24 Excavate Circuit Trench ~3 Wide X 4-5 Deep 24

25 Fabricate Circuit Piping Along Trench Above Ground 25

26 Bed Ditch, Place Header Piping in Ditch and Connect Each Loop 26

27 Hydrostatically Test the Circuit 27

28 Install Locater Wire and Backfill with Screenings 28

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32 Excerpt from HVAC System Comparative Study for the Signal Mountain High and Middle Schools Variable Air Volume (VAV) Ground Coupled Heat Pump (GCHP) First Cost $ 2,821,000 $ 3,687,400 Statistical Life Present Value $3,451,884 $4,027,695 Life Cycle Cost $25,058,731 $20,077,855 Annual Operating Cost/ sf Payback (years) $1.44 $

33 Key Points from the Comparative Study:

34 Key Points from the Comparative Study: Estimated additional first cost of approximately $850,000.

35 Key Points from the Comparative Study: Estimated additional first cost of approximately $850,000. In reality, this was closer to $1M.

36 Key Points from the Comparative Study: Additional first cost of approximately $850,000. In reality, this was closer to $1M. Estimated payback of 6.4 years.

37 Key Points from the Comparative Study: Additional first cost of approximately $850,000. In reality, this was closer to $1M. Estimated payback of 6.4 years. Actual payback of approx. 4 years.

38 Key Points from the Comparative Study: Additional first cost of approximately $850,000. In reality, this was closer to $1M. Estimated payback of 6.4 years. Actual payback of approx. 4 years. GCHP provides lower operating, maintenance and life cycle costs.

39 Key Points from the Comparative Study: Additional first cost of approximately $850,000. In reality, this was closer to $1M. Estimated payback of 6.4 years. In reality, this was approx. 4 years. GCHP provides lower operating, maintenance and life cycle costs. Estimated energy savings over the next 20 years of approximately $2 million.

40 Key Points from the Comparative Study: Additional first cost of approximately $850,000. Estimated payback of 6.4 years. GCHP provides lower operating, maintenance and life cycle costs. Estimated energy savings over the next 20 years of approximately $2 million. Actual 20 year payback closer to $3M.

41 Key Points from the Comparative Study: Additional first cost of approximately $850,000. Estimated payback of 6.4 years. GCHP provides lower operating, maintenance and life cycle costs. Energy savings over the next 20 years of approximately $2 million. Actual 20 year payback closer to $3M. According to the EPA, geothermal is the most energyefficient, environmentally clean, and cost-effective space conditioning system available.

42 Heritage High School: Ringgold, GA

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44 . HHS

45 Signal Mtn. Middle & High School

46 Signal Mountain MHS

47 Signal Mountain MHS

48 Signal Mountain MHS

49 262,250 ft Ea Signal Mtn. Middle- High School

50 Signal Mountain MHS

51 HIGH SCHOOL COMPARISON USAGE PER FT^2 KBTU 8 6 Signal Mtn Ooltewah Soddy Daisy Howard JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER January February

52 HIGH SCHOOL COMPARISON $0.25 $0.20 COST PER FT^2 $0.15 $0.10 Signal Mtn Ooltewah Soddy Daisy Howard $0.05 $- JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER January February

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56 Charlotte Office Building

57 Charlotte Office Building

58 Charlotte Office Building

59 Horizontal Bore Field Installation

60 Horizontal Installation: Section at Trench

61 Horizontal Borefield Installation

62 Alternate Heat Sink: A Lake

63 Lake as a Heat Sink

64 Lake as a Heat Sink

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66 Finished product: David Crockett State Park

67 Open Systems

68 Open Systems

69 HVAC System Comparison Dade County Courts Facility Estimated Square Footage = 28,680 Item Variable Air Volume Conventional Geothermal Variable Refrigerant Rooftop (VAV) Heat Pump Heat Pump First Cost 483, , ,600 Statistical Life Operating costs 45,314 27,246 33,842 Life Cycle Cost 3,266,747 2,617,422 2,608,741 Annual Operating Cost ($/SF) Annual Operating Cost 45, , , Simple Payback (years) *note - no incentives available in Dade Co. from Ga. Power - -

70 Hixson Middle School

71 Hixson Middle School

72 Questions? Thank you green spaces!