Fort Knox established energy efficiency standards in 2004 that were implemented in Building 1110. This included upgrades to HVAC, windows, lighting, insulation, and eliminating natural gas for heating and hot water. As a result, energy usage decreased 76% and earned an Energy Star award in 2008. The building now uses a geothermal heat pump system and high-efficiency electric heat pump water heaters to meet its needs, reducing costs and carbon footprint.

1. Fort Knox
Building 1110
Case Study

2. Fort Knox established
performance requirements for all
common systems on the base.
The design began implementation
in 2004 and included:
HVAC
Windows
Lighting
Roofing Systems
Insulation
Domestic Hot Water

3. Results of Systems Upgrades
•Improved energy efficiency
–Building 1110 received the
Energy Star Award in 2008
–Energy density was reduced
76% after complete renovation
to energy standards
•Improved indoor air quality
•Sustainable building
performance
•Eliminated natural gas for
space and domestic water
heating
•Smaller carbon footprint

4. Building 1110 – 2006 BTU Summary
Date Electricity Natural Gas Totals
Blended Electric Gas MMBTU Cost of
Month Kwh Total Cost $/kwh MMBTU Therms Gas Cost $/therm MMBTU Total Energy
Jan 48,480 $ 2,377.82 $ 0.049 165 19,044 $ 22,185.77 $ 1.17 1,904 2,070 $ 24,563.59
Feb 46,080 $ 2,580.19 $ 0.056 157 18,281 $ 21,297.77 $ 1.17 1,828 1,985 $ 23,877.96
Mar 52,080 $ 2,011.03 $ 0.039 178 13,736 $ 16,002.87 $ 1.17 1,374 1,551 $ 18,013.90
Apr 69,120 $ 2,086.92 $ 0.030 236 6,600 $ 7,688.44 $ 1.17 660 896 $ 9,775.36
May 106,560 $ 4,161.19 $ 0.039 364 3,307 $ 2,889.60 $ 0.87 331 694 $ 7,050.79
Jun 65,760 $ 3,541.44 $ 0.054 224 846 $ 739.01 $ 0.87 85 309 $ 4,280.45
Jul 67,200 $ 3,465.55 $ 0.052 229 691 $ 604.09 $ 0.87 69 298 $ 4,069.64
Aug 78,960 $ 5,615.71 $ 0.071 269 745 $ 650.68 $ 0.87 74 344 $ 6,266.39
Sep 39,600 $ 3,642.62 $ 0.092 135 2,852 $ 2,492.22 $ 0.87 285 420 $ 6,134.84
Oct 38,160 $ 2,744.62 $ 0.072 130 9,548 $ 11,123.78 $ 1.17 955 1,085 $ 13,868.40
Nov 48,960 $ 2,428.42 $ 0.050 167 11,916 $ 13,882.68 $ 1.17 1,192 1,359 $ 16,311.10
Dec 45,120 $ 2,647.01 $ 0.059 154 17,919 $ 20,876.10 $ 1.17 1,792 1,946 $ 23,523.11
Total 706,080 $37,302.52 2,410 105,486 $ 120,433.00 10,549 12,958 $ 157,735.52
Avg $ 0.053 $ 1.14

5. Building 1110 – 2008 BTU Summary
Date Electricity Natural Gas Totals
Blende Electric Gas MMBTU Cost of
Month Kwh Total Cost d $/kwh MMBTU Therms Gas Cost $/therm MMBTU Total Energy
Jan 88,080 $ 4,932.48 $ 0.056 301 - $ - $ - - 301 $ 4,932.48
Feb 89,280 $ 4,999.68 $ 0.056 305 - $ - $ - - 305 $ 4,999.68
Mar 78,960 $ 4,421.76 $ 0.056 269 - $ - $ - - 269 $ 4,421.76
Apr 82,800 $ 4,636.80 $ 0.056 283 - $ - $ - - 283 $ 4,636.80
May 64,320 $ 3,601.92 $ 0.056 220 - $ - $ - - 220 $ 3,601.92
Jun 66,720 $ 3,736.32 $ 0.056 228 - $ - $ - - 228 $ 3,736.32
Jul 69,840 $ 3,911.04 $ 0.056 238 - $ - $ - - 238 $ 3,911.04
Aug 79,680 $ 4,462.08 $ 0.056 272 - $ - $ - - 272 $ 4,462.08
Sep 76,560 $ 4,287.36 $ 0.056 261 - $ - $ - - 261 $ 4,287.36
Oct 70,560 $ 4,184.21 $ 0.059 241 - $ - $ - - 241 $ 4,184.21
Nov 60,720 $ 3,600.00 $ 0.059 207 - $ - $ - - 207 $ 3,600.00
Dec 66,720 $ 3,956.50 $ 0.059 228 - $ - $ - - 228 $ 3,956.50
Totals 894,240 $ 50,730.15 3,052 - $ - - 3,052 $ 50,730.15
Avg. $ 0.057 $ -

6. Pre and Post Installation Comparisons
•2006 Pre- installation average monthly costs, MMBTU
utilization, and total energy costs:
–Natural Gas Cost: $ 11,327
–Electric Cost: $ 3,026
–MMBTU 2006 Total 12,958
–Total 2006 Energy Cost $157,735
•Post-installation average monthly costs, MMBTU
utilization, and total energy costs:
–Natural Gas Cost: $ 0
–Electric Cost: $ 4,225
–MMBTU 2006 Total 3,052
–Total 2006 Energy Cost $ 50,730

7. Building 1110 – Electric Consumption
120,000
110,000
100,000
90,000
80,000
70,000
kWh 60,000
50,000
40,000
30,000
20,000
10,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

8. The System

9. Geothermal Heat Pump Systems
• 4 Million ft2 of buildings
installed for geothermal
heating and cooling
• 2.5 Million ft2 in planning
for next two years
• Best life cycle cost system
• Serving complex to simple
buildings
• Pulls constant water
temperature from ground
below
• Allows for energy sharing

10. Geothermal Well Field
• Consolidated Well Fields
– Provides heating,
cooling, and domestic
hot water
– Maximizes building
diversity
– Minimizes construction
expenses
– Minimizes construction
interferences

11. Geothermal Domestic Hot Water
•Efficient domestic hot
water
•Uses the investment of
the geothermal well field
•Minimal installation costs
due to the common well
field

12. The Unit for Water Heating

13. High Temperature (R134a)
208/230V, or 460V, 3Ph,
Capacity at: 380V, 3Ph, 50Hz
60Hz
Compressor
Water Heating Cooling Water Heating Cooling
Model
BTUH BTUH BTUH BTUH
WW-54 HT 54,000 39,000 48,000 34,000 Scroll
WW-96 HT 96,000 69,000 86,000 62,000 Scroll
WW-110 HT 110,000 80,000 96,000 70,000 Scroll
WW-165 HT 165,000 118,000 144,000 106,000 Scroll
WW-190 HT 214,000 154,000 172,000 124,000 Scroll
WW-330 HT 314,000 229,000 288,000 212,000 Scroll
WW-430 HT 420,000 303,000 364,000 280,000 Scroll
WW-820 HT 817,000 653,000 680,000 540,000 Screw
WW-1000HT 1,060,000 830,000 880,000 690,000 Screw

14. Refrigeration Schematic for a WWHP Unit

15. Summary
•GSHP – Ground Source Heat Pump technology was selected
for Fort Knox space heating and cooling
•Selecting GSHP technology eliminated natural gas for space
heating
•Converting domestic water heating to electric heat totally
eliminated natural gas needs for the building
•At 3.0 COP, HPWH for domestic water heating alternative the
building reduced the building water heating costs by 2/3rds
•Currently there are 54 Fort Knox buildings with E-Tech HPWH
for domestic water heating

16. Credits
•Installation by Harshaw Trane, Louisville, KY
•Energy Tables by Harshaw Trane