Heating & Cooling Efficiency

Transcription

1 Heating & Cooling Efficiency Advantages of Geothermal HVAC Efficiency Keith Swilley Gulf Power Company

2 Why Gulf Power Promotes Energy Efficiency? Customer Satisfaction Education Help Customers Make Smart Choices Load Management Maximize Generation Capacity

3 Heating and Cooling Systems Heat Pumps and Fossil Furnaces = How do they compare by efficiency? = How do they affect peak loads for utilities and customer billing? Efficiency Ratings, Comparisons and Choices Advantages of Ground Source Heat Pumps How do Utilities use A/C efficiency ratings? Costs Tax Credits Payback Geothermal Building Installations and Comparisons

4 Gas Furnaces..

5 Fossil Fuel Gas Furnace Conventional Technology 10 20% vent losses Combustion Air Hot Attic AFUE Rating? 80-95% to House 80% --Typical 100% Gas Input Extra Heat Gain Summer Extra Heat Loss Winter

6 Air Source Air Conditioners and Heat Pumps

7 Air Source Heat Pump Heating & Cooling degrees degrees

8 COP Annual Hours ODT Heat Pump (COP) Typical NW FL Historical Weather COP Geothermal HP This is why GSHP s need no auxiliary heat Outside Temperature (degree F)

9 Geothermal Heat Pumps

10 Geothermal Heat Pumps Variable Capacity Variable Efficiency Summer Winter Consistent Capacity and Consistent Efficiency

11 Ground Source Efficiency

12 Geothermal Heat Pump Fan Motor Refrigerant Coil Compressor Water-to-Refrigerant Heat Exchanger Water Entering Water Out

13 Types of Geothermal Loops Pond Horizontal Vertical

14 With Ground-Source HP s Avoid Condensing Unit Farms Concrete Footing/Slab Electrical material/labor Conduit to AHU s Refrigerant Piping - Distance? Fencing Gates Security Vandalism Landscape Costs

15 Typical Vertical Loop Typical Depth Feet

16 Summer

17 Closed Loop Geothermal Heat Pump Desuperheater or Heat Recovery FREE Hot Water

18 Heating Fuel Efficiency Comparison $1 get $5.00 worth of energy $1 get 80 to 95 cents worth of energy $1 get $3.00 worth of energy

19 Space Cooling Efficiency Ratings

20 Cooling Efficiency Air Source & Ground Source

21 HVAC Efficiency = Air Source Efficiency SEER SEER seasonal efficiency? EER specific operating condition? = Ground Source Efficiency EER EER = btuh output/watts ---- higher EER means less Kw.

22 A/C Efficiency Example A. 5 ton A/C w/10 EER 6 Kw B. 5 ton A/C w/12 EER 5 Kw (17% savings) C. 5 ton A/C w/18 EER 3.3 Kw (45% savings) Per hour of operation

23 Kw Demand Example A. 5 ton A/C w/10 EER 6 Kw B. 5 ton A/C w/18 EER 3.3 Kw Almost 3 Kw Less 100 Tons 300 Kw 500 Tons 500 Kw

24 A/C Efficiency What else do you need to know about efficiency ratings? How does SEER ratings compare to EER ratings? What happens at peak load operation?

25 A/C Efficiency, Did you Know? A/C Equipment AHRI Testing SEER Seasonal Energy Efficiency Ratio (80 Indoor EAT, 82 Outdoor Temp) EER Energy Efficiency Ratio (Efficiency at Peak Outdoor Conditions) (80 Indoor EAT/ 95 Outdoor Temp) Ground Source Equipment only EER (80 Indoor EAT based on EWT rating based on EWT ) Question when is the SEER the EER?

26 Air Source Efficiency (AHRI Rating 80/67/95) 18 SEER Energy Efficiency (EER) People think SEER is EER.

27 Air Source Efficiency (Maintain 75 INDOOR TEMP - 3 Ton Unit) Energy Efficiency (EER) 20+ EER EER 14 EER Low Speed (dual cap) Geothermal (85 EWT) High Speed (single cap) 13 EER 45% Less Efficient 11 EER 10 EER

28 HVAC Efficiency What do utilities care about?

29 HVAC Efficiency Utilities are most concerned with A/C equipment efficiencies at 95 degree outdoor temperature or the area/region peak outdoor temperature EER. Why? = it most represents peak load demand. = it affects utility T & D cost the most. = it affects generation and plant expansion planning = it affects critical peak pricing program design = has the overall greatest impact on utility DSM

30 HVAC Efficiency Heating Costs

31 Northwest Florida Cost of Heating Cost Per Million BTU s $30 $25 $25.00 $20 $21.05 $15 Gas 80% AFUE Gas 95% AFUE $12.89 $11.74 $10 $5 Standard Air Source Heat Pump 2.5 COP High Efficiency Air Source Heat Pump 3.0 COP $7.16 Geothermal 4.5 COP $0 Electric - $.11/KWH Natural Gas - $2.00/Therm AFUE - Annual Fuel Utilization Efficiency COP - Coefficient of Performance

32 HVAC Efficiency Cost per Btu - National Avg Example 1 Million Btu s Electric Rate 10 cents/kwh Natural Gas Rate $1.20/therm Gas Furnace 80% AFUE $ (fan energy) Gas Furnace 95% AFUE $ (fan energy) ASHP 2.5 COP $11.72 ASHP 3.0 COP $9.70 GSHP 4.0 COP $7.32 GSHP 5.0 COP $5.90

33 HVAC Efficiency Commercial Building HVAC System Efficiency

34 Chiller Efficiency Example Chiller VAV System -.5 kw/ton 24 EER Adding the auxiliary components: Air Handler Fans Chilled Water Pump Condenser Pump Cooling Tower Fan Zone or VAV Fans (No total system efficiency rating) Overall System Efficiency Result EER Source: July 2003 ASHRAE Journal article Estimating Demand and Efficiency, by Steve Kavanaugh.

35 Chiller System Efficiency Example (Actual 2010 New Commercial Building 120 Tons) Air Cooled Chiller 9.3 EER Kw Adding the Auxiliary Components: Chilled Water Pump kw Fan Coils kw Building Exhaust Fans -- 2 kw Total Auxilary kw Overall System Kw = 213 kw Overall Peak Full Load System Efficiency 120 tons x 12,000/213,000 watts = 6.7 EER (1.8 kw/ton)

36 Chiller System Efficiency Example (Actual 2011 New Commercial Building 550 Tons) Water Cooled Chiller 334 Kw Adding the Auxiliary Components: Water Pumps kw AHU kw Cooling Tower Fan kw Building Exhaust Fans -- 3 kw Total Auxiliary kw Overall System Kw = 623 kw Overall Peak Full Load System Efficiency 550 tons x 12,000/623,000 watts = 10.6 EER (1.1 kw/ton)

37 GSHP System Efficiency Example (Actual New Commercial Building Closed-Loop 116 Tons) Ground Source Heat Pumps 14 EER 99 Kw Adding the Auxiliary Components: Circulation Pump kw Building Exhaust Fans --.6 kw Total Auxilary kw Overall System Kw = kw Full Load System Efficiency 116 tons x 12,000/104,800 watts = 13.3 EER (.9 kw/ton)

38 HVAC System Metered Building 40 Tons Peak Load ~35 Kw.9 Kw/ton RED -- RTU s Roof Top Temp (.4-.5 Kw/ton less) Peak Load ~19 Kw Blue --GSHP s.48 Kw/ton

39 Full Load Space Cooling Watts Per Ton 13 SEER 15 SEER Energy (Watts) 18 SEER Dual Speed (High Cap) 18 SEER Dual Speed (Low Cap) Chillers GSHP s (High Speed/Full Cap) GSHP s (Low Speed Cap) Air 95 ODT GSHP s 85 EWT GSHP Low Speed < 70 EWT s

40 Geothermal Heat Pump Federal Incentives Residential Federal Income Tax Credit 30% of total GHP system cost, with no cap Commercial Building Federal Income Tax Credit 10% of total GHP system cost, with no cap Utility Efficiency Incentives? Accelerated Depreciation thru year depreciation for entire GHP system Eligible for bonus depreciation 50% write-off in first year.

41 Geothermal Installation Costs with Incentives Example 3 Ton System SEER Conventional Heat Pump System $7,000 Standard GSHP Single Speed System $15,000 30% Tax Credit ($4500) $3500 Added Cost SEER $500/ton Utility Incentive = $1500 Net Cost Difference $2,000

42 Geothermal Payback 3 Ton Example (Including Hot Water Recovery Benefits) (depending on actual cost of equipment options) w/tax Credit w/gp Utility Rebate SEER 5-7 Years 2-5 Years

43 Geothermal Commercial Buildings Buildings with HVAC Only yrs With 10% Tax Credit yrs Buildings with Geothermal HVAC and Geo Water Heating (water-to-water) yrs

44 Geothermal Building Projects

45 Corry Field Housing 200 Residential Housing Units Converted from natural gas to all electric Geothermal closed-loop systems Included Hot Water Recovery Units (built-in) Equipment Replaced cooking, cloths dryer, water heater, HVAC

46 Corry Field Housing Results 100% reduction in natural gas consumption 15% increase in electric consumption (Kwh) 30% decrease in overall energy costs (dollars) 65% reduction in Btu s/sf

47 Pensacola Naval Air Station 236 Units

48 100 Units Fort Walton, FL Existing Conventional A/C Conventional Electric Heat Electric Water Heating New Geothermal Closed-Loop Hot Water Recovery Units Post Results Energy Cost Reduction = 43%

49 Pensacola Beach Hotel Five Story rooms Geothermal Hybrid Application

50 Vertical Hybrid Closed-Loop

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52 Pensacola Beach Hotel Energy Cost Savings Performance Overall Cost Difference per SF - 24% per sq.ft. savings {compared to comparable beach hotel property} Geo Domestic Water Heating Cost Savings/gallon = 80% (Approx. $2 per room per month) Geo Pool & Spa Heat Pump Heating Savings = 86% (Total Cost Approx. $625 per month) 5 Geo Cooled Ice Makers vs Air Source cost Savings = 23% (Approx. $12 per month to Operate) Geothermal Space Conditioning 35-40% lower cost

53 Annual Operating Costs Comparison $2.27 Average savings for Geothermal Schools 2 $1.68 $ % GSHP $0.91 GSHP $0.73 GSHP $ ,000 sq ft 230,509 sq ft 75,069 sq ft Cost Per Square Foot 171,185 sq ft 112,420 sq ft 164,021 sq ft Geothermal School A School B School C Geothermal Geothermal Note: 12 month average Geo School - Closed Loop Geothermal System (completed Aug, 2000) School A - Gas Boiler/Chiller System (Updated w/ new equipment 1996) Charter School Closed Geo System School B - Air to Air Heat Pumps in classrooms; Gas/chiller in common areas (completed 1996) School C - All Electric-Gulf Coast Coop Washington Co. School Open Geo System

54 McDonalds Restaurant Actual KWH s Geothermal HVAC vs Conventional Restaurant 47% variation in monthly Kwh for Conventional Store RTU s KWH 13% variation in monthly Kwh for GSHP Store

55 Suggestions and Conclusions Geothermal HVAC offers the highest efficiency available because it ability to exchange energy to and from the earth. EER efficiency ratings at 95 degree outdoor temperature is a better measure to compare equipment efficiency because it s when A/C systems run the most.. Know what the EER is when selecting new or replacement systems. Using manufacturer Kw and btuh capacity performance data results in the best economic evaluation

56 Questions