Assessing bids for geothermal system helped homeowner understand the technology

Tuesday, March 2, 2010

Once we decided on a geothermal system, the first steps were getting educated and getting bids -- and the two processes were not unconnected.

The first bid for a complete installation came in at $37,000; even with tax breaks, that was way too high. I went shopping. The next two bids were considerably lower, $25,700 and $27,800. By comparing them, I learned a lot about different approaches to geothermal.

For example, the in-ground loop system can be installed vertically or horizontally. The first company proposed a horizontal configuration. That meant shallower drilling, but it would have spread out too far: Not only would it get too close to my septic system's drainage field, but it would have torn up most of my yard. By the time they laid hundreds of feet of piping, we would have faced a big landscaping bill. The other two companies wanted to go vertical.

Loop systems also can be open, -- meaning the fluid inside the pipes is water drawn from surface or underground sources, such as lakes or wells -- or closed. Montgomery County prefers closed systems, which don't discharge anything into the aquifer. We decided on a vertical closed-loop system.

We also decided that instead of buying a complete package from one company, we could save money by negotiating with individual contractors. To drill the holes and install the polyethylene piping and fluid, I picked Michael Barlow Well Drilling of Bel Air. Barlow has done occasional geothermal systems for years; the driller who showed up on-site told us that since the housing downturn has pretty much wiped out the market for drilling new water wells, geothermal is a much bigger part of the company's work.

For the crucial geothermal heat pump, we chose Griffith Energy Services, the Cheverly company that had been servicing our traditional HVAC for some years. We picked it even though Griffith had never put in a geothermal system -- our home would be its first attempt. But I knew them to be a responsive company, I liked the team of experts they assembled, and I figured that they'd take extra care to make sure their first geothermal venture would be done right. In addition, they were the lowest bidder and offered zero-percent financing.

Meanwhile, I was also getting information from Mark Schweber, owner of Water Works Plumbing in Gaithersburg, who took his own house geothermal last summer. It was invaluable to visit his home, check out his system and understand the process from someone who'd been through it and could verify that it had lowered his energy bills.

The original bidders had proposed using a traditional electric hot water heater with the geothermal system. But Schweber said, "That's like baking a cake without putting the icing on it," and proposed using the geothermal heat pump to keep a tank of hot water at about 80 degrees, at almost no extra operating cost. Then a high-efficiency tankless hot water heater, hooked to our existing propane tank, could cheaply kick it up to 120 degrees.

The tankless heater itself cost more, but it qualified for its own tax incentives, lowering the actual additional cost from about $3,000 to $1,500. And like the geothermal system, it's projected to be far cheaper to operate over time than traditional alternatives. We told Schweber we'd do it, and we were ready to begin.

-- Christopher J. Gearon

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