One of the most innovative technologies being used in the Yale Acres project is Geothermal Innovations’ Gi4TMHeat Exchanger which significantly cuts the geo-field over traditional U-Bend geothermal technology. Scientifically designed by Jim Hardin and University of Tennessee, the new Gi4™ has several advantages over U-Bend:
- Kidney shaped lobes create more circumference for heat exchange.
- Water held underground longer, more completely exchanges heat with earth.
- Water coming up is pressurized, allowing lower electrical costs for pumping.
- Pipes are wider than traditional U-bend, allowing fewer feet of exchanger and expensive drilling, per project.
- Insulating grout (grey area in diagram), is used to separate the supply and return.
- Result: the size and cost of the geo-field is reduced by 60% over U-bend.
With Gi4™, fewer, deeper bore holes can be drilled saving more space, time and cost
In an example demonstration in the upper Midwest, 400 ft. bores of Gi4™ gave 5 tons of HVAC capacity. U-Bend gives 1.6 Tons of capacity for each 250’ bore and installation.
- Hardin has installed its similar proprietary heat exchanger (BiSec) in 60 major projects over the past 5 years.
- Gi4™ installations began in 2010. It’s being used now for geothermal installations in Ohio, Michigan, Indiana, and New Jersey.
- It allows geothermal HVAC in large buildings or districts, where U-Bend systems lack space for the geo-field.
The first phase of the Meriden project will include a Gi4TM geo field that will service three of the buildings (twelve apartment units). The units are currently heated with heating oil that the residents must purchase and are later reimbursed for by the Housing Authority. The geothermal system will offer significant savings over heating with oil.