Heating & Cooling Efficiency

Keith Swilley

Gulf Power Company

Heating & Cooling Efficiency

Customer Satisfaction

Education – Help Customers Make Smart Choices

Load Management –

Maximize Generation Capacity

Heating and Cooling Systems

• Heat Pumps and Fossil Furnaces

= 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

Fossil Fuel Gas Furnace

Conventional Technology

Air Source

Air Source Heat Pump Heating & Cooling

20-40 degrees

800 600 400 200 CO P An nu al Ho urs ODT

Outside Temperature (degree F)

0 3.6 2.3 2.5 2.6 2.7 2.8 2.9 3.8 2 2.5 3 3.5 4 17 22 27 32 37 42 47 52

Heat Pump (COP)

Typical NW FL Historical Weather

Geothermal HP 4.5 – 5.5 COP

Variable Capacity Variable Efficiency Summer 90-95 Winter 30-50 Consistent Capacity and Consistent Efficiency

Types of Geothermal Loops

Pond

Horizontal

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

Typical Vertical Loop

Closed Loop Geothermal Heat Pump

Desuperheater

Cooling Efficiency

= Air Source Efficiency – SEER

SEER – seasonal efficiency?

EER – specific operating condition?

= Ground Source Efficiency – EER

EER = btuh output/watts

A/C Efficiency Example

A. 5 ton A/C w/10 EER – 6 Kw

B. 5 ton A/C w/12 EER – 5 Kw

C. 5 ton A/C w/18 EER – 3.3 Kw

(17% savings)

(45% savings)

Kw Demand Example

A. 5 ton A/C w/10 EER – 6 Kw

B. 5 ton A/C w/18 EER – 3.3 Kw

A/C Efficiency

• What else do you need to know about efficiency ratings?

• How does SEER ratings compare to EER ratings?

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 )

Air Source Efficiency

(AHRI Rating 80/67/95)

Air Source Efficiency

(Maintain 75 INDOOR TEMP - 3 Ton Unit)

What do utilities care about?

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

Northwest Florida Cost of Heating

Cost Per Million BTU’s

$25.00 $21.05 $12.89 $11.74 $7.16 $0 $5 $10 $15 $20 $25 $30

Electric - $.11/KWH Natural Gas - $2.00/Therm

Gas 80% AFUE Gas 95% AFUE Standard Air Source Heat Pump 2.5 COP High Efficiency Air Source Heat Pump

3.0 COP Geothermal _{4.5 COP}

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 – $15.00 + (fan energy) Gas Furnace 95% AFUE – $12.63 + (fan energy)

Commercial Building

HVAC System Efficiency

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

 Overall System Efficiency Result --- 7 – 8 EER

Source: July 2003 ASHRAE Journal article “Estimating Demand and Efficiency”, by Steve Kavanaugh.

Chiller System Efficiency Example

(Actual 2010 New Commercial Building 120 Tons)

Air Cooled Chiller – 9.3 EER -- 155 Kw Adding the Auxiliary Components:

Chilled Water Pump -- 15 kw

Fan Coils -- 41 kw

Building Exhaust Fans -- 2 kw

Total Auxilary -- 58 kw

Overall System Kw --- 58 + 155 = 213 kw

Overall Peak Full Load System Efficiency

Chiller System Efficiency Example

(Actual 2011 New Commercial Building 550 Tons)

Water Cooled Chiller – 334 Kw Adding the Auxiliary Components:

Water Pumps -- 90 kw

AHU -- 164 kw

Cooling Tower Fan -- 32 kw

Building Exhaust Fans -- 3 kw

Total Auxiliary -- 289 kw

Overall System Kw --- 289 + 334 = 623 kw

Overall Peak Full Load System Efficiency

550 tons x 12,000/623,000 watts = “10.6 EER”

(1.1 kw/ton)

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 -- 5.2 kw

Building Exhaust Fans -- .6 kw

Total Auxilary -- 5.8 kw

Overall System Kw --- 5.8 + 99 = 104.8 kw

Full Load System Efficiency

Peak Load ~35 Kw

Peak Load ~19 Kw

100-103 Roof Top Temp

.9 Kw/ton

.48 Kw/ton

Blue --GSHP’s RED -- RTU’s

HVAC System Metered Building – 40 Tons

Full Load Space Cooling Watts Per Ton

Energy (Watts)

GSHP’s (High Speed/Full Cap)

GSHP’s (Low Speed Cap) Air Source

@ 95 ODT GSHP’s

85 EWT GSHP Low Speed _{< 70 EWT’s} Chillers

13 SEER 15 SEER

18 SEER Dual Speed (High Cap)

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 2013

 5-year depreciation for entire GHP system

Geothermal Installation Costs

with Incentives Example

3 Ton System

13-14 SEER Conventional Heat Pump System – $7,000

Standard GSHP Single Speed System – $15,000 30% Tax Credit – ($4500)

$3500 Added Cost 13-14 SEER

Geothermal Payback

3 Ton Example

(depending on actual cost of equipment options)

w/Tax Credit w/GP Utility Rebate

Geothermal Commercial Buildings

Buildings with HVAC Only -- 5 – 10 yrs

With 10% Tax Credit -- 4 – 8 yrs

Buildings with Geothermal HVAC

and

Geo Water Heating (water-to-water) -- 3 – 6 yrs

Geothermal Building Projects

Corry Field Housing

• 200 Residential Housing Units

• Converted from natural gas to all electric

• Geothermal closed-loop systems

Corry Field Housing

Results

100% reduction in natural gas consumption

15% increase in electric consumption (Kwh)

Pensacola Naval Air Station

Post Results – Energy Cost Reduction = 43%

100 Units – Fort Walton, FL

Existing New

Pensacola Beach Hotel

Five Story - 117 rooms

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

Annual Operating Costs Comparison

Cost Per Square Foot

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 310,000 sq ft 230,509 sq ft 75,069 sq ft

171,185 sq ft 112,420 sq ft 164,021 sq ft

GSHP $0.97

Average savings for Geothermal Schools

McDonalds Restaurant

Actual KWH’s Geothermal HVAC vs Conventional Restaurant 47% variation in monthly Kwh for Conventional Store

13% variation in monthly Kwh for GSHP Store

KWH

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.