Southern Geothermal, headquartered in Evans,
Ga., uses a D16x20 Series II Navigator horizontal directional drill (HDD),
manufactured by Vermeer, for completing horizontal loop system installations.
Photos by Southern Geothermal.
The setting is one of the most prestigious locations in the South-or perhaps anywhere in the country for that matter. Often referred to as “Beverly Hills of the East,” Atlanta’s famed Buckhead district is home to the ninth-wealthiest ZIP code in the nation (30327), and a median annual household income of more than $350,000. Situated within the gently rolling hills and dense forests are some of the most stately and glorious mansions in the entire Southeast.
It was in Buckhead that Rick Daniel and John Peebles, founders and co-owners of Southern Geothermal, headquartered in Evans, Ga., were called on to assist in remedying problems with a multi-ton geothermal heating/cooling system positioned beneath the meticulously landscaped site of a new 10,000-square-foot mansion. A premature malfunction with one of three vertical loops installed directly beneath the million-dollar-plus home prior to construction-and well before the completion of the elaborate landscaping surrounding the home-was in need of repair, so the homeowner chose Southern Geothermal to provide a solution.
Installing a replacement system using the vertical drilling approach would likely result in severely damaging the now-established grounds-an obviously costly proposition for the homeowner. Southern Geothermal offered a less intrusive option, and since they had successfully completed more than 900 geothermal installations already, they were well-qualified for the job.
“Trenchless was the only option without incurring a lot of construction damage,” Daniel says, explaining that heavy vertical drilling equipment would have wreaked havoc with the grounds and damaged the landscaping and the 500-yard-long, winding cobblestone driveway. Daniel says HDD equipment is much more compact and far less intrusive, as well as more cost-effective.
Prior to starting Southern Geothermal, Peebles worked with some of the top HVAC companies in the Augusta, Ga., area as a service technician. In 1997, he founded his own company, Peebles HVAC, specializing in geothermal systems installations. At the time, Peebles HVAC was one of only five heating and air conditioning companies installing geothermal systems in Georgia. Peebles describes the 2007 installation of 300 geothermal units at Fort Gordon Military Base in nearby Augusta as a defining moment for his company. After several years of steady growth spawned by the increasing awareness of the many benefits of geothermal heating/cooling systems, Peebles teamed up with Daniel, an experienced and successful business and marketing strategist, to create Southern Geothermal in 2011. That same year, Peebles and Daniel purchased a D16x20 Series II Navigator horizontal directional drill (HDD), manufactured by Vermeer, for completing horizontal loop system installations.
Southern Geothermal fixes problems with a multi-ton geothermal heating/cooling system positioned beneath the meticulously landscaped site of a new 10,000-square-foot mansion in Atlanta.
Leaving a Minimal Footprint
Perhaps more so than any of the previous geothermal installation jobs Peebles and Daniel tackled, the Buckhead project demanded the utmost care and sensitivity to surroundings. Hence, a horizontal-loop installation configuration was the obvious choice.
Peebles says using HDD makes jobs much easier and is far less invasive than using vertical drilling equipment, which often disrupts surroundings. “On the Buckhead project, we were able to drill beneath a courtyard walkway, the front yard and under a cobblestone driveway with virtually no visual effects or damage,” Peebles says.
The drill plan developed by Peebles and Daniel was based on the original system’s specifications and tonnage requirements as calculated by the HVAC contractor. Geothermal system load calculations are determined based on several factors: square footage of the structure, ground conditions/conductivity, climate and usage. Once they have calculated the system’s capacity requirement, Southern Geothermal then puts an installation plan into action.
After receiving the load system specifications for the Buckhead project, Peebles and Daniel mapped out a drill plan that called for completing three 300-foot bores-one each for the three circuits needed to support the 3-ton capacity load requirement of the system. According to Daniel, the cooling load of most geothermal systems requires installing more loop material than is required for heating. Climate and soil conditions are also major considerations for determining load calculations.
The drill operator encounters areas of wet clay, hard-packed clay and some shale.
Soil conditions on the Buckhead job consisted of varying densities and compositions of clay, along with scattered deposits of shale. Along the lengthy bore paths, drill operator David Faircloth would often encounter areas of wet clay followed immediately by a hard-packed composition of the same substance, with some shale thrown in for good measure. Since Peebles had drilled in the area many times before and had extensive knowledge of soil conditions, he did not complete soil profiles in advance. They used a straight bentonite drilling fluid mixture to ensure they maintained the integrity of each bore.
The men positioned the Vermeer D16x20 Series II horizontal directional drill-selected by the company’s founding duo largely because of its compact frame and thrust/pullback capabilities conducive for the majority of horizontal geothermal loop material installations-on a small parcel in the courtyard of the property within 8 feet of the home to minimize the footprint. It wasn’t necessary to reposition the drill for each of the three 300-foot bores; instead they adjusted the angle placement of the drill on the second and third bores in order to accommodate for a 10-foot distance between each of the three loops. Drilling depths averaged from 10 to 20 feet along the 300-foot bore paths.
Upon the completion of each bore, the heat-fused sections of SDR-11 polyethylene tubing-material ideal for geothermal fluid conductivity-were pulled back through the bore path using the D16x20 Series Il drill. The three loops were then connected to the header situated beneath the courtyard and, from there, on to the house and the existing HVAC system. Peebles says the project was completed successfully and without incident.
Southern Geothermal is exper-ienced in completing both horizontal and vertical geothermal-loop systems applications, both of which, Peebles says, are equally effective and efficient. The compact frame and corresponding minimal footprint of the Vermeer drill made HDD equipment the best option for the Buckhead project, allowing them to drill beneath established landscapes, driveways and retaining walls with minimal adverse effects. With the help of this equipment, their strategy paid off, leaving behind a satisfied homeowner. ND
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