Thursday, June 23, 2005

"I'm An Old Pipe Liner"*

Today starts the most intriguing part of our house resoration. McNair Brothers Drillers came today to drill and se the pipes for our geothermal heating unit. When costing out adding second floor radiators AND putting in some type of "space pack" central air conditioning system, I realized geothermal was not much more expensive. We are having horizontally bored pipes installed.
At the back of our neighbors yard were set the plastic 2.5 inch pipes that will make the underground loops


The drill unit and and the water truck were set at the front of the house.

The gas, water, phone, etc. lines were all flagged. We need four 200 foot loops for our system, each loop is roughly equivalent to one ton of heating/cooling power. The drill would go down to a depth of 30 feet below the surface run 200 feet to the back of our property and come up again. Here is the start, the drillers were also taking digital pictures and plan to have a website up soon:

The driller sits and reads his display telling pitch of the line, depth, etc.

The rig carries 300 feet of pipes in three stacks of 10 ten foot lengths. When needed the next section automatically drops into place, is lubricated and attached the previous piece

A second crew member walks above the line as it goes, and carries a device that communicates with the driller. He marks every 10 feet where the line is.

Here is the remote sensor:

When the drill comes near the end of the property it is angled back up, and in our case surfaces in the neighbor's yard.

The bore is removed and replaced with a reamer bit

This bit will hook onto both ends of the loop that will be carried back through the hole

As the bore retreats the pipe is pulled through, and water and bentonite are pumped into the hole at the same time filling the entire area around the pipe, this is crucial in getting energy transfer from the ground to the pipe.

The first loop started at 10:15 and was completed with pipes back up at 11:15. The driller said it was like going through butter. I was grateful and left to go teach. When I came back at 5:00 everyone was gone and my front looked like this:

They had drilled 4 of the 5 needed loops in one day (fifth loop is to go into the house). You can see that they ran two loops on either side of the gas line, but all four lines are significantly deeper underground than the gas line. Once the system is running the only thing I will be using natural gas for is the gas insert in the fireplace and the stove. The last loop will then head under the house and then up into the pit dug into the floor in the basement (I forgot to get a picture of that) Then the heat pump will be placed on top of where the loop comes in. All of the lines run under the house at a depth of nearly 30 feet below surface. What I am truly amazed by is that the little bit of mud you see in front is the entire byproduct of a total of 800 feet of underground drilling!

Tomorrow the roofers come!

* Title of one of my favorite songs sung and played by local Iowa City music legend Al Murphy

4 comments:

SmilingJudy said...

That's fascinating! Thanks for posting the pics for us to see how it's done.

Derek said...

That's so cool, I don't think it would work on our small city lot though. What is the cost to run the system?

Mike said...

I thought people would like to see how it works.

As to cost, most estimates are a 35% to 65% reduction in your monthly heating bill. There is a resistence electrical unit for when it gets below zero in the winter and ground heat is not enough, however our utility will meter us at the lowest possible rate since we are using geothermal.

Another interesting feature is that when the hot air is pumped out of the house in the summer it goes past the hot water tank, essentially providing free hot water in the summer.

When the heat pump etc. is installed I'll take more pictures and post again.

In a small lot your only real option is vertical drilling which is expensive and messy. I saw what the vertical wells did for our school additions, horizontal bore is much better when it is an option.

Derek said...

Is that 0f? Then we wouldn't even need the back up here.