Rig maneuverability is a key concern in GSHP retrofit work. Moving them into the backyard of an established home and landscape can be troublesome, and may result in significant restoration costs.

The popularity of ground-source heat pumps (GSHPs) among homeowners has been on the rise in recent years. According to industry sources, much of the growth (10-20 percent during each of the past 10 years) can be attributed to energy savings and the green factor. GSHPs have been popular in new home construction, but that trend is changing based on the recent economic conditions.

“I’ve watched the transition over the last few years go from new construction to retrofit,” said Mike Kapps with WaterFurnace International. “Ground-source heat pumps were a great option for new construction, and it was easier for the homeowner to justify the cost by rolling it into their overall mortgage.

“Now the retrofit market has expanded and it makes up about 70 percent of GSHP sales, compared to only 10 percent a few years ago.”

What’s behind the shift? New home sales are down and homeowners are living longer in existing homes, rather than staying a few years and moving into other homes or upsizing. Investing in a GSHP system makes sense because they will be living in the home for a longer period of time. Current energy and government incentives are also driving the retrofit market.


The steady growth of the GSHP market has also created some challenges - like a shortage of experienced loop installers. Many times a project must be delayed to accommodate the schedule of a loop installation contractor.

“There are regions of the United States where there’s a shortage, but then there are areas where if you need a residential loop installation contractor, you could get three or four to quote a single project,” Kapps said.

The risk of being at the mercy of a subcontractor to install the loops is prompting some HVAC contractors to bring loop installations in house. As more HVAC contractors consider this option, it’s important to understand the pros and cons.

Pros: The HVAC contractor can have more control over the installation schedule and potentially, better control over costs.

Cons: Depending on the installation method selected, the cost to purchase equipment can run into the mid to high six-figure range. Then you need to find a qualified operator.


There are a number of equipment options to install horizontal and vertical loops, ranging from well-drilling rigs to excavators and trenchers to horizontal directional drills. Each has its advantages and disadvantages.

Well-drilling rigs are equipped to bore vertical holes in an efficient manner. They have been a popular choice. However, they lack the compact stature needed in many retrofit applications. In most cases the rigs are large, and trying to maneuver them into the backyard of an established home and landscape can be troublesome, resulting in significant restoration costs. In addition, contractors can expect to pay in the mid six figures for a new machine.

Another consideration is service/support. Many of these units are sold direct from the manufacturer and may lack a local or regional contact to help with service and support after the sale.

Open-cut trenching equipment - rubber tire trenchers, compact excavators, and backhoes - offer a lower purchase cost and typically are sold by manufacturers that have a solid dealer network to provide service and support. However, open-cut installations can cause significant damage to existing landscapes, resulting in additional restoration costs.

Horizontal directional drills are becoming more compact and lighter, allowing contractors to access space-restricted areas, and reducing damage to the existing landscape.

Depending on the manufacturer and model, some units can also complete both vertical and horizontal loop installations. The cost for a new, mid-sized, horizontal directional drill starts in the low six figures.

Finding an experienced operator for a horizontal directional drill can be a challenge. However, most drill manufacturers and their dealership networks offer training to support companies after the sale.


Training abounds within the industry to help contractors better understand how GSHP systems work, as well as how to properly install them. However, it all begins with industry standards. These have been developed by the International Ground Source Heat Pump Association (IGSHPA).

The association’s Accredited Installer Program is a three-day workshop that covers all aspects of the GSHP system installation process. Topics covered include the basics of designing the system, to loop installation, to installation of the mechanical equipment inside the residence or building.

A more focused training program, the Accredited Drillers Training Program, covers aspects of the loop-installation process. It’s really designed for underground and water well-drilling contractors who are interested in installing vertical loops. It’s also a good resource for HVAC contractors looking to bring the loop installation process in house.

“Attending a training program creates a better education model for that contractor and helps them compete in the marketplace,” said John Clapp with the IGSHPA. “It gives them all the tools necessary to know how to correctly design and install a GSHP system. Better-educated contractors lead to better-installed systems, and that helps improve the market as a whole.”

IGSHPA isn’t the only entity offering training to contractors. Heat pump manufacturers like WaterFurnace also offer training and support.

Clapp pointed out that some states may also require underground contractors to complete state-specific licensing requirements. These vary by state and even down to the county level in some areas. Communicate with your state’s Department of Natural Resources to completely understand the licensing and regulation process.

Training is only the beginning. Just because a contractor completes a training course and becomes certified, it doesn’t mean he has the experience to install a loop system.

“Whether you’re installing horizontal or vertical loops, the drill operator needs some experience to complete a quality job,” said Ed Savage with Vermeer Corp. “When installing horizontal loops, you can get into many different soil conditions over a 500-foot bore. But when drilling vertically, it’s amazing how many different types of soils - topsoil, clay, gravel, and sand - you can drill through in a single bore. Training gives you the tools to complete a successful bore, but properly boring that hole takes some experience.”


For Williams Comfort Air, Indianapolis, the decision to bring GSHP loop installations in house was an easy one. It boiled down to scheduling.

“When using a subcontractor to install the loops, we were at their mercy,” said Terry Biggs with Williams Comfort Air. “It was difficult to commit to a customer when their system would be up and running, because you’re using a subcontractor who works for several other different HVAC contractors. Another factor was controlling costs, and we felt we could do a better job in house.”

Williams Comfort Air began installing GSHP systems in 1983 and brought the loop-installation process in house in 2007. Today the company has two full-time loop-installation crews that typically install up to 200 systems annually.

Biggs looked at a number of installation options and chose horizontal directional drilling as the preferred method for the area and customer base.

“The majority of our work is focused on residential retrofits that feature well-landscaped yards,” said Biggs. “So we chose the most homeowner-friendly installation option we could find. With horizontal directional drilling, we can come in and excavate a 3- by 6-foot entry pit and complete our boring within that space.

“When we are done, the soil goes back in the hole and the sod is replaced. Within a few weeks you can’t tell we were even there.”

The contractor uses a patent-pending process called The Williams Vertizontal™ - a dead-end hole or steep-angle bore - to install and house the loops. The horizontal directional drill is positioned at the entry pit at a 30-degree pitch angle. The crew then drills to a depth of about 100 feet, at which point the drill head and stem is extracted and the loop is pushed down into the bore hole and grouted.

Once one loop is installed, the drill rig is rotated slightly and another bore hole is created. The process is repeated until the required number of loops is installed.

“It’s an ideal installation method for our area since some of the yards are only 85 feet wide, and that really limits our options,” said Biggs. “Plus, we are only working in one small area and damage to the existing landscape is minimal. It’s a much cleaner and less expensive restoration option than bringing in a well-drilling rig, or using open-cut equipment to install the loops.”

However, Biggs faced some challenges bringing the loop installation process in house. The biggest was understanding the geographical conditions. The White River flows through Indianapolis, and with a river there is a lot of sand, gravel, and rock below the surface. So understanding how best to bore through these different formations was an education in itself.

The second challenge was learning how to operate a directional drill. Biggs and his team watched other contractors and picked up some tips, but it also involved just going out and doing it.

“We purchased Vermeer horizontal directional drilling rigs and their sales team has been great in spending time with our teams to educate them on the drilling process,” said Biggs.

Vermeer’s Ed Savage encourages contractors to visit with HVAC companies already installing GSHP loops, as well as equipment manufacturers. If you decide to bring loop installation in house, make sure to dedicate resources to properly train and market the team.

And when it comes to equipment, make sure to become aligned with a manufacturer or dealer who understands the market, and has the pieces in place to support the equipment, team, and business after the sale.

Publication date:06/20/2011