geothermal heat pump case study i chiloquin community center: 16 vertical boreholes + water-water...
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Geothermal Heat PumpGeothermal Heat PumpCase Study ICase Study I
Chiloquin Community Center:
16 vertical boreholes + water-water heat pump providing radiant floor heating and cooling
Andrew ChiassonAndrew ChiassonGeo-Heat CenterGeo-Heat Center
Oregon Institute of TechnologyOregon Institute of Technology
Chiloquin Community CenterChiloquin Community Center
• Location and Background:Location and Background:
Southern Oregon, east of Cascades
Building Use: Art gallery, library, meeting hall, Sherriff Dept.
Gross Floor Area: 13,000 ft2, single floor
Construction: New in 2003, insulated concrete form (ICF)
Winter: Avg. Jan. low = 22oF , 7000 heating degree days
Summer: Avg. Jul. low = 85oF , 200 cooling degree days
Chiloquin Community CenterChiloquin Community Center
• Ground Source System:Ground Source System:
Ground Temp. = 56oF
Thermal Conductivity = 0.62 Btu/hr/ft/oF (dry sediments)
16 vertical boreholes (4 x 4 grid pattern), 300 ft deep, 20 ft spacing
Single U-tube, thermally-enhanced grout
Methanol/water solution
Chiloquin Community CenterChiloquin Community Center
• Interior System:Interior System:
Radiant floor heating & cooling
One 15-ton water-water heat pump controls water temperature in a storage tank, which provides a “thermal buffer”
15 zones on variable-speed pumps
Ventilation air (4,000 cfm) handled by an energy recovery unit in the attic, controlled by occupancy and CO2 sensors
Web-based building controls
Chiloquin Community CenterChiloquin Community Center
• Project Costs and Economics:Project Costs and Economics:
Total HVAC system cost: $237,400 ($18.26/ft2)
Geothermal loop portion: $48,000 ($3.69/ft2)
Economic Incentives:
Oregon Business Energy Tax Credit = $80,000
Annual HVAC Energy Use:
5.8 kWh/ft2 => $5,350 ($0.41/ft2)
Geothermal Heat PumpGeothermal Heat PumpCase Study IICase Study II
Acknowledgement: Information and data provided by Ed Lohrenz, Ice-Acknowledgement: Information and data provided by Ed Lohrenz, Ice-Kube SystemsKube Systems
South Cariboo Recreation Centre, British Columbia:
Integrated Geothermal Heat Pump HVAC/R at a Hockey Arena
S. Cariboo Ice ArenaS. Cariboo Ice Arena
• Energy use in arenasEnergy use in arenas
S. Cariboo Ice ArenaS. Cariboo Ice Arena
• Ice arenas have many simultaneous heating and cooling loadsIce arenas have many simultaneous heating and cooling loads
S. Cariboo Ice ArenaS. Cariboo Ice Arena
• Integrated geothermal heat pump systemIntegrated geothermal heat pump system
Earth loop
Thermal storage buffer
Low temperature water-water heat
pumps
Ice surface
Radiant floor heat
Chilled fluid side of heat pumps
Hot fluid side of heat pumps
Preheat for make up water
Snow melt
Forced air heat pumps
Fluid cooler
DHW Dehmidification/heating/cooling
S. Cariboo Ice ArenaS. Cariboo Ice Arena
• System summary and benefitsSystem summary and benefits ~84 tons of refrigeration for ice rink ~20 tons for dehumidification ~10 tons for service hot water ~48 tons heating/cooling for arena, offices, lobby, change
rooms Earth loop used only when building temperatures are met Eliminates ammonia refrigeration and:
associated stringent safety precautions oil disposal costs annual compressor rebuilds regular monitoring
Heat pumps use 10% of the refrigerant charge of conventional
Heat pumps use non-toxic R404A, and can operate down to 0oF on the evaporator side and 125oF on the condenser side
S. Cariboo Ice ArenaS. Cariboo Ice Arena
• System economicsSystem economics
Energy Cost Comparison
$0
$10,000
$20,000
$30,000
$40,000
$50,000
$60,000
$70,000
$80,000
$90,000
$100,000
$110,000
$120,000
Conventional System Integrated Geothermal
En
erg
y C
ost
Other Electric
Air Conditioning
Hot Water
Heating
Dehumidification
Pumps
Refrigeration
• 2-year payback with federal incentive, 3-years without2-year payback with federal incentive, 3-years without
Maintenance Cost
Geothermal Heat PumpGeothermal Heat PumpCase Study TBA?Case Study TBA?
Acknowledgement:Acknowledgement: Ministry of Natural Resources CanadaMinistry of Natural Resources Canada
Supermarkets
Vegetable Display
Supermarket Entrance
Supermarket Interior