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
|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
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
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
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
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
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?
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An exercise in Energy Smart, Not So Big living.
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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.
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