Geothermal ground loop installation. Photos at our energy efficient home in Deep Creek Lake, MD

Construction Timeline: (Geothermal Ground Loop)
Follow the progress of our new home construction. (10/20/2002 - ???)

NOTE: Newest pictures at the top.
Click on any image for an enlargement.
Note: For details about the HVAC design (which includes the Geothermal Exchange system) visit our GREEN HVAC page.

Feb 15, 2003 Four months later we've changed from really hot, to frigid cold & it's time to terminate the loops. We really need the heat now to warm the internal house structure enough to dry out any excess moisture in the wood framing before installing the drywall.

The walls have been framed, and sheathed in plywood to make installation of the equipment easier. Since the loop pipes were fed through the wall in pairs (inlet followed by outlet) all the odd pipes were connected to form an inlet manifold (lower pipe) and all the even pipes were joined to form an outlet manifold. A pump-pack supplied by Water Furnace regulates the flow of water in the 5 parallel loop circuits. The pipes are 1 1/4" diameter, and are fully insulated with a black foam blanket.

The Water Furnace Pump Pack also facilitates the filling, purging and pressurizing of the ground loop. There are two pumps that run in a push-pull configuration to ensure a strong flow. Click the image to see more detail.

On the other side of the room, the ground loop lines are in the process of being split between the two Ground Source (Geothermal) Heat Pumps. The ground loop is fed to each unit through a flow-regulating valve.

The water-water unit can be seen on the right. Go to the Equipment Room page to see more images of the HVAC system.

October 22, 2002 Drilling the Geothermal wells and installing the tubing was extremely messy.
Combine heavy machinery, dirt, clay, rain and sloped ground to get a real messy work site. I really didn't imagine that this was going to be as involved as it turned out being. Had I known that all the rocks were only on the surface, I really think I would have opted for horizontal slinky loops. The guys from "Wayne's Water 'N Wells" made the best of a messy situation. Their team persevered to get the job done right.

Our bores were drilled by "Wayne's Water N' Wells". Here's Wayne with the truck they used to do the drilling. You can get an idea of the grade of our slope by the height they had to jack the front wheels up. We have 5 wells that will will contain geo-exchange tubing that will let us tap into the constant ground temperature. 4 wells are 214' deep, the fifth well is only 150' (oops).	In this installation they drilled the 5 wells first, and installed steel casings (the exposed tops are circled) for the top 20' to stop the wells collapsing. The truck in the foreground was fitted with a lifting boom, and the truck in the background was used for mixing and pumping the "grout" that is used to fill the holes after the tubing is installed.
Knisley (The HVAC co.) has prepared the ground loops in advance and trucked them to the site. A "Loop" is essentially two coils of pipe joined by a "U" fusion splice. The tubing has "feet" markings along it's length to verify correct installation. A length of tubing at the splice is bound to a strip of wood to protect it during transport.	Here you can see the splice close-up. The plastic tape is just used to bind it to the wood temporarily. This is the only join in each ground loop, since each length of tubing runs from the bottom of the well, up to the surface, along a ground trench and into the utility room through a hole in the concrete retaining wall.
Here we see the "WWW" team about to install a ground loop. The crane has a cable attached to the top of the casing, and is pulling it out of the ground. The guy in green is holding the termination (U) while the two guys on the left prepare to unwind the two coils of tubing. Once the casing is removed, the termination is placed in the hole, and the tubing slowly fed down. If all goes well, the termination hits bottom when the markings on the tubing say 214. Naturally, it didn't always work out that way, and Wayne ended up having to re-drill a portion of one well.	These guys are feeding the mixer/pump that feeds the "grout" into the well after the tubing is installed. The grout is pumped into the well using a long "extension" tube made up from a series of shorter pipes (see pic at left). Sections are removed as the hole fills up. I though the grout was going to be like cement, but it turns out it's a material made from clay (I think) mixed with some polymer to give it a consistency like oatmeal. Apparently it will stay like this for quite a while.
This is what the well looks like after it's been grouted. It's really very sloppy. Lisa said it felt like "Sn*ot", but I wouldn't repeat that here :)	For those of you with a high speed connection, I've included a short video clip (2 MB) of the team feeding the tubing into the well. Just right-click the player and select save as.
This shot shows the black ground loops entering the Utility Room. So now all they have to do is put a heat pump between the two sets of pipes. Easy eh?

This site is all about building a cool, energy efficient house, that makes maximum use of earth sheltered design, passive solar heating and cooling, geothermal exchange energy management, and right sizing of the house for it's designated use. The home's placement is on a south-facing hillside in Deep Creek Lake, Maryland. This site describes the design process, the technologies used and the expected results. We also have a comprehensive Links Page for anyone who is also interested in designing a similar project.