Monday, November 25, 2013

Warmth Returns!

Not outside, but here in the Nature Center. As many of you know at the end of last winter the old fuel oil furnace bit the dust. Limping along on used parts (as that unit was found to be obsolete) we made it through the rest of the cold weather. Fast forward to the end of October and try as we could, the old furnace was really dead. Until the new system could be installed, we had to use electric oil space heaters. They did okay, but still.....brrr!

Enter in our new heating and cooling system which just happens to be geothermal! It has been pretty exciting and I have some pictures to share with you from the process. These pics are courtesy of one of OHS's Archaeologists who was on site to monitor the various earth moving activities.

The first step was to drill 3 wells into the earth. This was the start of the first one.

The drilling rig was quite large. This picture is taken from near the back cabin. Can you see how tall the rig is? There are also coils of black flexible pipe that will be inserted down each well.

In preparation for the substances that will come out of the ground as a result of the drilling, a silt fence was put up. This will help guide the mess away from the main walking areas and keep it somewhat contained.

Here is comes! See the grayish white stuff? There ended up being quite a lot when it was all said and done.

 Can you see China?  :)

Here are all three wells finished. Each well is 150 feet deep.

Next, a trench is dug so that the three wells can be connected together.

This was a pretty big trench! There were some cool pieces of sandstone that were dug up as well as these ugly creatures.

Any guesses? As adults, they provide the classic sounds of summer.....Cicadas! These are the larval form and spend several years underground feeding on sap from plant roots. I'm pretty sure that these are Annual or Dog-day Cicadas and not the Periodical, but if someone out there knows better - let me know!

Check out some of the cool features of this insect. Big eyes, and slender antenna are easily seen. If you look carefully you can see the wing forming that the adult will use to get around. But to me, the coolest feature are the huge claws on the front legs! Wow! They need those big claws for digging. Females lay eggs in twigs and once the eggs hatch the nymph digs its way underground. When it is time to emerge as an adult, the nymph has to dig its way back out again!

Anyway, back to the geothermal system...

At the same time the trench was being dug, a horizontal drilling machine was employed to get pipe from the wells to the Nature Center. This was a neat way to do it because there was no need to excavate another trench. If that had happened, it would have been a big disturbance right in front of the Nature Center.

Tom had previously dug a big hole next to the foundation of the Nature Center. This was so an entry point for the pipe could be drilled through the foundation and into the basement. In the picture above, you can see the entrance of the horizontal driller to the big hole!

Then, it was time for the pipe.

Here is the pipe going into the basement. The hole can be filled in again.

Here is a great shot of how that horizontal drilling save the Nature Center from some ugly and muddy digging.

Now the last step for the outside work was to connect all three wells together and the pipes that go to the Nature Center.

Okay, really the last step was to fill in the trench! Once the grass grows back next spring, you'll never even know what happened!  

Now with everything connected, the inside work could be done. So our system is called a closed loop system. What that means is that all that pipe that was ran essentially makes one big loop. And circulating through that loop is a special fluid. That fluid becomes the same temperature as the earth around it deep in the ground. The pipes eventually make their way to the furnace and well, that's where the magic happens. 

As I write this, I am enjoying the warm temperature in the Nature Center and have an good feeling about how efficient and "green" the system is. It's nice to not rely on fuel oil any more.


  1. Robyn: How much did this new installation cost in total? Do you know how many square/cubic feet the system is heating? (We're thinking about doing something like this for our visitor center building.)