During this seminar we will discuss the design and operational characteristics of a geothermal HVAC system. We will explore the different configurations of a geothermal system including standing column, horizontal loop, vertical loop and pond loop systems. We will compare geothermal HVAC systems with conventional HVAC systems relative to first costs, operating costs, functionality and maintenance focusing on commercial buildings. Learning Objectives: -Develop an understanding of how a geothermal heat pump system operates. -Have the ability to assess if a building is a candidate for a geothermal heat pump system. -Understand the environmental, operational and cost benefits of a geothermal heat pump system.

1. So called global warming is just a
secret plot by wacko tree huggers to
make America energy independent,
clean our air and water, improve the
fuel efficiency of our vehicles, kick
start 21st century industries and make
our cities safer and more livable.
Don’t let them get away with it.
Chip Giller, Grist.Org

2. GeothermalSystems
Geothermal Systems
for
for
CommercialBuildings
Commercial Buildings

3. Presenters:
Brian Smith, PE, LEED AP
Principal, Allied Consulting Engineering Services
Steve Sakakeeny, CPG, LSP, CHMM
Principal, SAK Environmental
D.J. Quagliaroli
President, DRAGIN Geothermal Well Drilling

4. Allied Consulting Engineering Services, Inc. is a Registered Provider
with the American Institute of Architects Continuing Education
Systems. Credit earned on completion of this program will be
reported to CES Records for AIA members. Certificates of
Completion for non-AIA members are available on request.
This program is registered with the AIA/CES for continuing
professional education. As such, it does not include content that
may be construed to be an approval or endorsement by the AIA of
any material of construction or any method or manner of handling,
using, distributing, or dealing an any material or product. Questions
related to specific materials, methods, and services will be
addressed at the conclusion of this presentation.

5. Copyright Materials
This presentation is protected by US and International copyright
laws. Reproduction, distribution, display and use of the
presentation without written permission of the speaker is
prohibited.
©2009 Allied Consulting Engineering Services, Inc.
consulting engineering services, inc.

6. L
E
Develop an understanding of how a
A
geothermal heat pump system
R
operates.
N O
I B
Have the ability to assess if a
N J building is a candidate for a
G E geothermal heat pump system,
C including technical and regulatory
T obstacles.
I Understand the environmental,
V operational and cost benefits of a
E
geothermal heat pump system.
S

7. H
O
R
I
Z
O
N
T
A Loops are installed in trenches 5-10 feet below
surface.
L
L
Requires 2,500 square feet per ton of cooling.
O
Generally installed in areas with moist sand or
O
dirt.
P
Must understand hydrology.

8. V
E
R
T
I
C
A
L
Boreholes are drilled several hundred feet deep.
L
Requires 200-250 linear feet per ton of cooling.
O
O
P

9. P
O
N
D
L
Geothermal loop is installed directly into a pond
O
or other body of water near the building.
O
Size and depth of pond must be analyzed to
P
ensure sufficient capacity.
Man made ponds/lakes are often installed to
accommodate a pond loop simultaneously adding
to the aesthetics of the property.

10. S
T
A
N
D
I
N
G C
Wells are drilled 1,000 – 1,500 feet deep.
O
L Generally installed in areas with shallow
bedrock (within 200’)
U
M Heat transfer medium (water) comes into direct
contact with heat sink/source (rock), resulting in
N
higher efficiency than closed systems.

11. HOW
IT
W O RK S

12. Heat flows downhill
From a higher temperature to a lower temperature

13. 10 BTU
Let’s take 1 pound of water at 80°F and
heat it to 90°F by adding 10 BTU

14. 10 BTU
Now let’s take 1 pound of water at 90°F
and let it cool to 80°F and give up 10 BTU

15. Heat
What if we could cool 1 pound of water
from 50°F to 40°F?

16. 10 BTU
We would get 10 BTU.

17. Heat
What happens when we put heat into
water at 212°F ?

18. Everyone knows Water boils at 212°F.

19. 970 BTU
It takes 970 BTU to change 1 pound of water
at 212°F to 1 pound of steam at 212°F.

20. In Denver, Colorado, water boils at 202°F.

21. In the olden days, before microwave ovens,
folks used a Pressure Cooker to cook foods faster.
Water boils at 240 °F at 10 PSIG
250 °F at 15 PSIG

22. In the classic high school
physics experiment water can
be made to boil at any
temperature by reducing the
pressure.
This concept is the basis of
modern air conditioning.
Except air conditioners don’t
use water they use
Halogenated Chloro Fluoro
Carbons like
Chlorodifluoromethane and
Zeotropic blends of Fluorinated
Halocarbons like
difluoromethane and
pentafluoroethane.

24. 40.00 83.255
40.00 83.255 21.662 108.313
21.662 108.313

25. 40.00 83.255
40.00 83.255 21.662 108.313
21.662 108.313
120.00 274.65
120.00 274.65 45.952 112.914
45.952 112.914

54. What
are the
benefits?

56. Geothermal
vs.
Conventional

57. U
D
E
u
S u
I
G
N

58. D
E
S
I
G
N

59. D
E
S
I
G
N

60. D
E
S
I
G
N

61. Boilers

62. Smoke Stack

63. Water Chillers

64. Earth Shaker 2000

65. Cooling Towers

66. Legionnella

67. Project Example: Zero Arrow Street
Zero Arrow Street, Cambridge, Massachusetts

68. Z
E
R 40,000 Square Feet
O
A Mixed Use: Office/Black Box Theater
R (American Repertory Theater)
R
O
W
Urban Setting
Heated and Cooled with Three 1,500 Foot
S Standing Column Wells
T LEED Certified
R
E
E
T

69. Z
E
R FIRST COSTS OF EACH SYSTEM TYPE
O
Ground Source Heat Pump (GSHP):
A
R Wells = 3 x $55,000 = $165,000
R
O
W
Water Source Heat Pump (WSGP):
Cooling Tower = $30,000
S Boiler = $12,000
T
R
Cost Difference:
$165,000 – ($30,000+$12,000) = $123,000
E
E Other components are approximately equal for
T both systems (i.e. heat pumps, ductwork,
piping)

70. Annual Energy Costs
Budget Building Design
Cooling Heating Interior Pumps Interior Domestic
Ventilation Lighting Water
kWh 55,311 22,193 1,816 25,058 94,344 70,298
Therms 0 8713
Cost $0.180 $0.180 $0.180 $0.180 $0.180 $0.180
$/KWhr
Cost $1.90 $1.90 $1.90 $1.90 $1.90 $1.90
$/Therm
Annual $9,955.92 $19,697.56 $326.81 $4,510.36 $16,982.00 $12,653.39
Costs
TOTAL $64,978.23

71. Annual Energy Costs
Proposed Design
Cooling Heating Interior Pumps Interior Domestic
Ventilation Lighting Water
kWh 50,097 31,476 594 23,834 94,344 70,298
Therms 0 0 0
Cost $0.180 $0.180 $0.180 $0.180 $0.180 $0.180
$/KWhr
Cost $1.90 $1.90 $1.90 $1.90 $1.90 $1.90
$/Therm
Annual $9,017.39 $10,547.91 $106.95 $4,290.12 $16,982.00 $12,653.39
Costs
TOTAL $48,715.67

72. Z
E
R Energy Savings
1
O
A WSHP Cooling $9,956
R WSHP Heating $19,698
R
O WSHP Total $29,654
W
GSHP Cooling $9,017
S GSHP Heating $10,548
T
GSHP Total $19,565
R
Geothermal Heat Pump Savings:
E
$29,654 - $19,565 = $10,089
E
T

73. Z
E
R
O
A
Simple Payback
R
R
O System Cost Differential $123,000
W
Geothermal Heat Pump Savings $10,088
S
T
R
E Payback = $123,000 ÷ $10,000/yr. = 12.2 years
E
T

74. M
A Water Source Heat Pump
I Cooling tower water treatment
N
Cooling tower fan belts
T
Outdoor piping (roof) exposed to weather
E
N Cooling tower exposed to weather
A VFD’s can be fussy (control of CT fans)
N Boiler service (mandatory once/year)
C
E

75. M
A Ground Source Heat Pump
I Building loop water treatment/test and add
N chemicals if necessary
T Other components (i.e. heat pumps and
E water pumps) require equal maintenance for
N both systems
A
N
C
E

76. Geothermal Benefits
Free heat
No fossil fuel hazards
Reduced carbon footprint
Enhanced serviceability
No outdoor noise
No visual impact outdoors
Positive cashflow day one
Savings increase overtime
10% Tax Credit (30% Residential)

77. Certified Professional Geologists,
Hydrogeologists, Chemists
Geology
Aquifer testing
(hydraulic and thermal)
Well design
Construction inspection
Water quality considerations
Regulatory permits

78. Standing Column Well
Water circulation in 1 well
800 ft. to 1,500 ft. deep
Surface bleed for thermal
balance
Gravity injection
Permitting

79. Designing to the Environment
YOUR ANSWERS ARE UNDERGROUND!
Geology affects thermal capacity of well
Water yield affects thermal capacity of well
Water quality affects:
Corrosion rates
O&M
Regulatory considerations

80. Aquifer Characteristics
Water yield
Rock density
Thermal conductivity
testing – Btu/ft-hr oF

81. C
Brackish water –
O
corrosion and water management
N
Collapsing bore hole
S
I
Waste management
D
Boston Groundwater Trust (Back
E Bay)
R
A
T
I
O
N
S

82. Regulatory Permitting: Applicable Rules
Underground Injection (UIC) Control Program
Groundwater discharge Permit Program (314
CMR 5.00)
MADEP Guidelines for Ground Source Heat
Pump Wells, February 2009

83. Regulatory Concerns
Data base of injection wells
Thermal pollution
Cross-contamination of aquifers

84. Registration under the UIC Program
Initial registration
Significant system modifications
Change in ownership
Well closure

85. Water Quality Testing
Required for all open loop wells
“Conditional” to “Full” registration
Exceedance may require water treatment
Copper and Lead on return flow

86. E NT
U RR TS
C EN
EM
Q UIR Other permitting requirements:
RE
Bleed water to dry well –
UIC registration
Bleed water to sewer or storm
drain – local permit
Bleed water to surface water –
not allowed until Massachusetts
federal EPA permit renewed

87. E NT
U RR TS
C EN
EM
Q UIR Treatment and expanded
RE permitting required if:
Water quality limits exceeded, or
Using treatment chemicals (i.e.
disinfectants, scale inhibitors)

96. consulting engineering services, inc.
Questions?
Thank you for your time.
This concludes the American Institute of Architects
Continuing Education Systems Program.
Allied Consulting Engineering Services
215 Boston Post Road Sudbury, Massachusetts
43 Jefferson Boulevard Warwick, Rhode Island
978-443-7888 alliedconsulting.net
Environmental, LLC