Abstract
A new type of ground heat exchanger that utilizes the excavation often made for basements or foundations has been proposed as an alternative to conventional ground heat exchangers. This article describes a numerical model that can be used to size these foundation heat exchanger (FHX) systems. The numerical model is a two-dimensional finite-volume model that considers a wide variety of factors, such as soil freezing and evapotranspiration. The FHX numerical model is validated with one year of experimental data collected at an experimental house located near Oak Ridge, Tennessee. The model shows good agreement with the experimental data-heat pump entering fluid temperatures typically within 1°C (1.8°F)-with minor discrepancies due to approximations, such as constant moisture content throughout the year, uniform evapotranspiration over the seasons, and lack of ground shading in the model.
| Original language | English |
|---|---|
| Pages (from-to) | 1059-1074 |
| Number of pages | 16 |
| Journal | HVAC and R Research |
| Volume | 17 |
| Issue number | 6 |
| DOIs | |
| State | Published - 2011 |
Funding
A low-energy research house with an FHX in Oak Ridge, Tennessee, was chosen for validation of the numerical model. The selected house is one of four houses built in 2009 for a research project undertaken by Oak Ridge National Laboratory (ORNL) and several partners, including the U.S. Department of Energy, the Tennessee Valley Authority (TVA), and several industry partners. The house demonstrates one of four strategies implemented in the four houses, which are about 55%–60% more efficient than traditional new construction. The house is heavily instrumented (with more than 250 sensors) and has been monitored to assess its performance since construction was completed in 2009. The details of the house’s specifications can be found in Miller et al. (2010).
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | |
| Oak Ridge National Laboratory | ORNL |
| Tennessee Valley Authority |
