0
Research Papers

Feasibility Study of a Residential Hybrid Ground Source Heat Pump System

[+] Author and Article Information
Siddharth Balasubramanian

Oracle America Inc.,
95 Network Drive,
Burlington, MA 01803
e-mail: siddharthbala@utexas.edu

Jonathan L. Gaspredes

Smith and Nephew,
7000 West William Cannon Drive,
Austin, TX 78735
e-mail: gaspredes@gmail.com

Tess J. Moon

Department of Mechanical Engineering,
University of Texas at Austin,
Austin, TX 78712
e-mail: moon@austin.utexas.edu

Glenn Y. Masada

Department of Mechanical Engineering,
University of Texas at Austin,
Austin, TX 78712
e-mail: masada@mail.utexas.edu

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS. Manuscript received November 4, 2015; final manuscript received February 4, 2016; published online April 5, 2016. Assoc. Editor: Ali J. Chamkha.

J. Thermal Sci. Eng. Appl 8(3), 031004 (Apr 05, 2016) (9 pages) Paper No: TSEA-15-1314; doi: 10.1115/1.4032763 History: Received November 04, 2015; Revised February 04, 2016

A residential hybrid ground source heat pump (HGSHP) model is presented, which integrates a compact cooling tower with a GSHP. The base case GSHP model is for a single story, 195 m2 house with a 14 kW heat pump and four 68.8 m deep vertical boreholes and uses Austin, TX weather data. The GSHP model was run for a range of supplemental heat rejection (SHR) capacities of an unidentified device located between the heat pump outlet and ground loop inlet, and estimates of improved heat pump performance and ground temperature effects are presented. Then, a compact closed wet cooling tower (CWCT) model is presented and coupled to the GSHP model. The tower's 7 kW capacity represents the smallest commercially available cooling tower. Each of the four HGSHP boreholes was reduced to 26.5 m. The operational and economic performance of the HGSHP is compared to a GSHP alone. Metrics include estimates of initial and lifetime operational costs, ground temperature effects, and heat pump efficiency. Simulations for ten years of operation show that adding the compact CWCT is cost effective, extends the lifetime of the borehole system, and maintains high heat pump efficiencies.

FIGURES IN THIS ARTICLE
<>
Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Annual net heat rejected to the ground for the GSHP base case with different SHR capacities

Grahic Jump Location
Fig. 2

Annual mean ground temperatures near borehole for GSHP base case with different SHR capacities

Grahic Jump Location
Fig. 5

Schematic of CWCT (redrawn from Ref. [19])

Grahic Jump Location
Fig. 6

Control volume of tube section (redrawn from Ref. [19])

Grahic Jump Location
Fig. 4

Ground loop length ratio versus % heat rejected by SHR (redrawn from Ref. [17])

Grahic Jump Location
Fig. 3

Schematic of HGSHP

Grahic Jump Location
Fig. 10

Monthly averaged heat pump EWT for ten-year operation: HGSHP

Grahic Jump Location
Fig. 11

Monthly averaged heat pump EWT for ten-year operation: GSHP

Grahic Jump Location
Fig. 12

Heat pump COP and EER for ten-year operation: HGSHP

Grahic Jump Location
Fig. 13

Heat pump COP and EER for ten-year operation: GSHP

Grahic Jump Location
Fig. 7

Cooling and spray water temperature profiles through cooling tower (experimental data from Ref. [19])

Grahic Jump Location
Fig. 8

Air temperature profile through cooling tower (experimental data from Ref. [19])

Grahic Jump Location
Fig. 9

Air enthalpy profile through cooling tower (experimental data from Ref. [19])

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In