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A Simplified Procedure for Sizing Vertical Ground Coupled Heat Pump Heat Exchangers for Residences in Texas
Abstract
A simplified technique for the sizing of vertical
U-tube ground coupled heat pump (GCHP) heat
exchangers for Texas climates was developed
utilizing a transient simulation model of a ground
coupled heat pump and weather and soil data for
Texas. The simulation model discretized the ground
heat exchanger into elements and computed the
temperature distribution surrounding the heat
exchanger on a minute-by-minute basis. Hundreds
of runs were made with the model for a wide range
of ground temperatures, ground thermal properties
(density, thermal conductivity, and specific heat),
and outdoor weather.
A set of sizing charts were developed from the
model runs that could provide quick reference on the
size of the ground heat exchanger. Corrections for
ground temperature, ground density, ground thermal
conductivity, and indoor air temperature were
presented. Soil temperature and thermal
conductivity were found to be the most important
parameters for sizing GCHP heat exchangers.
Results from the simplified method were
compared to two available heat exchanger sizing
methods: the National Water Well Association
(NWWA) and the International Ground Source Heat
Pump Association (IGSHPA). The simplified
method predicted shorter lengths than those from
either of these two methods.
Citation
O'Neal, D. L.; Gonzalez, J. A.; Aldred, W. (1994). A Simplified Procedure for Sizing Vertical Ground Coupled Heat Pump Heat Exchangers for Residences in Texas. Energy Systems Laboratory (http://esl.tamu.edu); Texas A&M University (http://www.tamu.edu). Available electronically from https : / /hdl .handle .net /1969 .1 /6648.