ASHRAE Journal - October 2014 - 34
TECHNICAL FEATURE
Ground Source Heat Pumps
In Texas School District
BY STEVE KAVANAUGH, PH.D., FELLOW ASHRAE
The Leander Independent School District (LISD) is located in one of the fastest growing
suburbs of Austin, Texas. The district maintains 36 buildings that use ground source
heat pump (GSHP) technology and garnered an average 2010 ENERGY STAR rating of
97.1 LISD has fostered a team of local design engineers, ground loop contractors, general
contractors, and architects who interact closely with their construction, maintenance
and energy management staff. Teamwork is essential because new elementary schools
are added at a rate of one per year with very tight construction schedules. The fast-paced
construction of LISD schools has not negatively affected energy consumption since the
average ENERGY STAR rating for newer schools is over 99.
Figure 1 provides the annual electrical energy consumption for the all-electric buildings. The turnkey construction costs of recently completed GSHP systems (HVAC,
outdoor air, controls and ground loop) are in the range
of $20/ft2 to $24/ft2 ($215/m2 to $260/m2) of floor area.2
Given the significant quantity and cost of outdoor air
systems with energy recovery, these systems are comparable in cost to non-GSHP systems and provide savings
in both energy and maintenance costs.
Owner's Perspective
With more than 21,000 vertical bores and 2,100+ miles
of U-tube heat exchanger piping,3 the area surrounding
Austin has perhaps the largest concentration of GSHP
institutional and commercial buildings in the U.S. In
1994 LISD adopted many local practices, but also did a
few things differently to reduce installation and maintenance costs. The GSHP system is a simple unitary
approach with each classroom heat pump connected
to an individual ground loop with an on-off circulator
pump.
LISD brought together its primary engineering firm,
general contractor, several architects and their staffs to
evaluate the program in 1997-98. The school board and
superintendent supported additional upfront spending
on quality, but they wanted proven life-cycle costs based
Steve Kavanaugh, Ph.D., is a professor emeritus of mechanical engineering at the University of Alabama, Tuscaloosa, Ala.
34
ASHRAE JOURNAL
ashrae.org
O CT O B E R 2 0 1 4
ASHRAE Journal - October 2014
Table of Contents for the Digital Edition of ASHRAE Journal - October 2014
Contents
ASHRAE Journal - October 2014 - Cover1
ASHRAE Journal - October 2014 - Cover2
ASHRAE Journal - October 2014 - 1
ASHRAE Journal - October 2014 - 2
ASHRAE Journal - October 2014 - Contents
ASHRAE Journal - October 2014 - 4
ASHRAE Journal - October 2014 - 5
ASHRAE Journal - October 2014 - 6
ASHRAE Journal - October 2014 - 7
ASHRAE Journal - October 2014 - 8
ASHRAE Journal - October 2014 - 9
ASHRAE Journal - October 2014 - 10
ASHRAE Journal - October 2014 - 11
ASHRAE Journal - October 2014 - 12
ASHRAE Journal - October 2014 - 13
ASHRAE Journal - October 2014 - 14
ASHRAE Journal - October 2014 - 15
ASHRAE Journal - October 2014 - 16
ASHRAE Journal - October 2014 - 17
ASHRAE Journal - October 2014 - 18
ASHRAE Journal - October 2014 - 19
ASHRAE Journal - October 2014 - 20
ASHRAE Journal - October 2014 - 21
ASHRAE Journal - October 2014 - 22
ASHRAE Journal - October 2014 - 23
ASHRAE Journal - October 2014 - 24
ASHRAE Journal - October 2014 - 25
ASHRAE Journal - October 2014 - 26
ASHRAE Journal - October 2014 - 27
ASHRAE Journal - October 2014 - 28
ASHRAE Journal - October 2014 - 29
ASHRAE Journal - October 2014 - 30
ASHRAE Journal - October 2014 - 31
ASHRAE Journal - October 2014 - 32
ASHRAE Journal - October 2014 - 33
ASHRAE Journal - October 2014 - 34
ASHRAE Journal - October 2014 - 35
ASHRAE Journal - October 2014 - 36
ASHRAE Journal - October 2014 - 37
ASHRAE Journal - October 2014 - 38
ASHRAE Journal - October 2014 - 39
ASHRAE Journal - October 2014 - 40
ASHRAE Journal - October 2014 - 41
ASHRAE Journal - October 2014 - 42
ASHRAE Journal - October 2014 - 43
ASHRAE Journal - October 2014 - 44
ASHRAE Journal - October 2014 - 45
ASHRAE Journal - October 2014 - 46
ASHRAE Journal - October 2014 - 47
ASHRAE Journal - October 2014 - 48
ASHRAE Journal - October 2014 - 49
ASHRAE Journal - October 2014 - 50
ASHRAE Journal - October 2014 - 51
ASHRAE Journal - October 2014 - 52
ASHRAE Journal - October 2014 - 53
ASHRAE Journal - October 2014 - 54
ASHRAE Journal - October 2014 - 55
ASHRAE Journal - October 2014 - 56
ASHRAE Journal - October 2014 - 57
ASHRAE Journal - October 2014 - 58
ASHRAE Journal - October 2014 - 59
ASHRAE Journal - October 2014 - 60
ASHRAE Journal - October 2014 - 61
ASHRAE Journal - October 2014 - 62
ASHRAE Journal - October 2014 - 63
ASHRAE Journal - October 2014 - 64
ASHRAE Journal - October 2014 - 65
ASHRAE Journal - October 2014 - 66
ASHRAE Journal - October 2014 - 67
ASHRAE Journal - October 2014 - 68
ASHRAE Journal - October 2014 - 69
ASHRAE Journal - October 2014 - 70
ASHRAE Journal - October 2014 - 71
ASHRAE Journal - October 2014 - 72
ASHRAE Journal - October 2014 - 73
ASHRAE Journal - October 2014 - 74
ASHRAE Journal - October 2014 - 75
ASHRAE Journal - October 2014 - 76
ASHRAE Journal - October 2014 - 77
ASHRAE Journal - October 2014 - 78
ASHRAE Journal - October 2014 - 79
ASHRAE Journal - October 2014 - 80
ASHRAE Journal - October 2014 - 81
ASHRAE Journal - October 2014 - 82
ASHRAE Journal - October 2014 - 83
ASHRAE Journal - October 2014 - 84
ASHRAE Journal - October 2014 - 85
ASHRAE Journal - October 2014 - 86
ASHRAE Journal - October 2014 - 87
ASHRAE Journal - October 2014 - 88
ASHRAE Journal - October 2014 - HR1
ASHRAE Journal - October 2014 - HR2
ASHRAE Journal - October 2014 - HR3
ASHRAE Journal - October 2014 - HR4
ASHRAE Journal - October 2014 - HR5
ASHRAE Journal - October 2014 - HR6
ASHRAE Journal - October 2014 - HR7
ASHRAE Journal - October 2014 - HR8
ASHRAE Journal - October 2014 - HR9
ASHRAE Journal - October 2014 - HR10
ASHRAE Journal - October 2014 - HR11
ASHRAE Journal - October 2014 - HR12
ASHRAE Journal - October 2014 - HR13
ASHRAE Journal - October 2014 - HR14
ASHRAE Journal - October 2014 - HR15
ASHRAE Journal - October 2014 - HR16
ASHRAE Journal - October 2014 - HR17
ASHRAE Journal - October 2014 - HR18
ASHRAE Journal - October 2014 - HR19
ASHRAE Journal - October 2014 - HR20
ASHRAE Journal - October 2014 - HR21
ASHRAE Journal - October 2014 - HR22
ASHRAE Journal - October 2014 - HR23
ASHRAE Journal - October 2014 - HR24
ASHRAE Journal - October 2014 - HR25
ASHRAE Journal - October 2014 - HR26
ASHRAE Journal - October 2014 - HR27
ASHRAE Journal - October 2014 - HR28
ASHRAE Journal - October 2014 - HR29
ASHRAE Journal - October 2014 - HR30
ASHRAE Journal - October 2014 - HR31
ASHRAE Journal - October 2014 - HR32
ASHRAE Journal - October 2014 - 89
ASHRAE Journal - October 2014 - 90
ASHRAE Journal - October 2014 - 91
ASHRAE Journal - October 2014 - 92
ASHRAE Journal - October 2014 - 93
ASHRAE Journal - October 2014 - 94
ASHRAE Journal - October 2014 - 95
ASHRAE Journal - October 2014 - 96
ASHRAE Journal - October 2014 - 97
ASHRAE Journal - October 2014 - 98
ASHRAE Journal - October 2014 - 99
ASHRAE Journal - October 2014 - 100
ASHRAE Journal - October 2014 - 101
ASHRAE Journal - October 2014 - 102
ASHRAE Journal - October 2014 - 103
ASHRAE Journal - October 2014 - 104
ASHRAE Journal - October 2014 - Cover3
ASHRAE Journal - October 2014 - Cover4
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QJLWMC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_MCDEBX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WNYSQY
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XATVOD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_FJSHSS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_CCBZDS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XDEFVG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2023november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2023november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_VHGNBL
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WPKBNJ
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_UUVCDE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RTGDEW
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2023
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_LKRFXS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_AZSOFG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ERCDBH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QWDFRV
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JHGVDF
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OPUYHG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SREIBM
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_LRTGLK
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OKRFGH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2022november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2022november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TZSERA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_LVRUIX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RPTVYZ
https://www.nxtbook.com/nxtbooks/ashrae/mini_pub_catalog
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XIYTGD
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2022
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RFGDOB
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_PABXNU
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_REMKLS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_PICVBT
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_AOYTVW
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JQOPLS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_IOYTBC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SGAJJF
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_IGHYER
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_PDRKLS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2021november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2021november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XCODFR
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QSLFGO
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ILKVNM
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2021
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OPDJKD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_VJKSRY
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SDHUTC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JPPKRR
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SDLTTH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_CKLLES
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SLDOX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_HJETUK
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OLUHGE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2020october
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2020october_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ZERDGH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QVMNEO
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RTPOKE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_BBATRE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_STUBMW
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TPEMPE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JNMKDS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_FBTTPA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WQMMNE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TVBRYN
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_showguide2020
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_KTUZMA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ABEDGD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201910
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201909
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019septmeber_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019september
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201908
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201907
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201906
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201905
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201904
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019april
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201903
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019march
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201902
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201901
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_showguide2019
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018december
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018october
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2018
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201810
https://www.nxtbook.com/nxtbooks/ashrae/ashraeinsights_201806
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201805
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201804
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201803
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201712
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201711
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201710
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201709
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201705
https://www.nxtbook.com/nxtbooks/ashrae/ashrae_meetinginsert_201610
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acrexindia
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer
https://www.nxtbook.com/nxtbooks/amca/2014summer2
https://www.nxtbook.com/nxtbooks/amca/2014summer
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acma_2014summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201311
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201309
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acmasupp_2013fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201305
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201303
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2013winter
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201211
https://www.nxtbook.com/nxtbooks/ashrae/achr_expo_mexico2012
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201209
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v3
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v2
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201205
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201203
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012winter
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201111_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201109_v2
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2011summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201105
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201103
https://www.nxtbookmedia.com