Geothermal for the Farm

T-bone!

Have you heard about geothermal?  It’s a simple heating and air-conditioning technology that’s been around since the 1940s.  And it’s super-efficient.  The most efficient gas furnace is 94% efficient, but a ground source heat pump (geothermal) is 400% efficient!  That’s because a ground source heat pump uses a little energy to go get a lot of energy from the ground.   In our quest for low-to-no bills, we’re very excited to have geothermal in our home.

trenching

A ground source heat pump pumps a water/antifreeze mix into a pipe loop that’s buried in the ground.  Like a cave, the ground is cooler than outside air in the summer and warmer than outside air in the winter.  I like to think of geothermal heat and air as renewable energy because it’s using free energy from the ground, and that free energy will always be there. 

In the summer, the heat pump uses electricity to pump the water mix into the ground loop.  The water mix coming out of the house is hot – it contains the heat that we’re trying to get rid of in the summer.  As the water mix travels through the ground loops, it cools because the ground is about 55 degrees.  That cool water returns to the house, and the heat pump delivers cold air to the home – air conditioning!  It works the same in the winter, except the water mix leaving the house is very cold, and it gets warmed up when it travels through the ground. 

Trenches were 220' long each.

We’ve been really interested in geothermal for a long time, so interested that we scrounged around and drove all the way down to Georgia to get a great deal on a 6-foot blade Ditch Witch.  One look at the beast, and we named it “T-bone”.   We used T-bone to trench four trenches that were 220 feet long and 6 feet deep each.  We laid black water pipe in the trenches – 6 feet down going away from the house and looping back at four feet down coming back to the house.    We pushed the dirt back into the trench and tamped it hard so the dirt would have great thermal contact with the pipe (the water mix will cool/heat faster).  All the pipes are connected together in a manifold and brought back to the house.  The total length of pipe is about 1,780 feet.  The water mix will travel that whole length before returning back to the house.

Next steps are duct work and installing the ground source heat pump inside the house.  With a small house, loads of insulation, and geothermal heating and air, we’re really excited to see how low our electric bill will be.  Wish us luck!

Going Green, Minus the Bright and Shiny

Are you as sick as we are about “going green”?  It seems that going green equals going shopping for something flashy – a new hybrid SUV, new eco materials for the home, etc.  Around here, even DC’s humongous new baseball stadium is labeled “green,” as evidenced by the holy blessing of LEED certification.  We have a friend of a friend who tore down a perfectly good (but old) house and built a new one, equipped with all the latest Energy Star appliances, bamboo flooring, and the like.  All of this is built on consumerism, which plays right into the hands of Wall Street types.  There’s profit in new cars, new construction, and pretty things, “green” or not.  Green is just a new sales category.

What about the REAL going green, the kind we never hear about on TV?  It’s the kind that tries to minimize both waste and wasteful spending.  (And flaunting wealth is certainly the ultimate in wasteful spending.)  It’s bent towards conserving the old, because consuming new stuff isn’t green at all. 

New 2x4 on left, 100+ year old 2x4 on right. The old one is much denser and heavier.

We’re trying to keep it real with the farm house.  It’s small, and was built over 100 years ago.  At first, it was hard to look past the tiny rooms, but I soon realized that the rooms were framed in old timbers – dense, heavy old-growth pine that doesn’t warp and wane like modern 2” x 4”s.  This house has great bones, and there was no justification for tearing it down and building a new one out of poor-quality materials.

One of our goals is to get our utility bills down as close to zero as possible.  We hate bills!  We kept running into loads of valuable energy efficiency research done here in the U.S., but implemented in Europe.  Europe has many near zero-energy homes, and they’ve done it simply with loads of insulation and tight construction.  New bamboo flooring and shiny recycled glass tile does not play into it.  Glass tile is sexy; insulation is decidedly not, unless the pink panther does something for ya. 

We decided that insulation is the way to go.  Most newer homes have R-13 insulation in the walls (R-13 is the same thickness as a modern 2” x 4” stud).  Some homes have R-19, which is thicker and prevents more energy loss than R-13.  But homes in Europe have R-45!   We set out to replicate this on the cheap.  We figured out the best method is to just build an additional 2” x 6” wall inside the existing exterior walls of our house.  This will bring us to R-45.  When Mike introduced this idea to me, my first thought was “Whaaaa?  The rooms will be even smaller!”  But I thought about it.  Our goal is to have next-to-nothing bills, not to have rooms that will store lots of crap we don’t need.  I caved.      

Double wall in closet

The only room we have renovated so far is the walk-in closet.  The exterior wall is super-thick.  We don’t have central heat and air yet, and last winter we were heating with a kerosene burner.  The house was very chilly, but the closet was cozy.  Another thing we noticed was the complete absence of drafts in the closet, even during the monster double blizzard the DC area got in February. 

We feel good about living contrary to “green” consumerism.  Insulation isn’t pretty, isn’t expensive, and it’s literally behind the scenes.  (By the way, doesn’t this describe most of the REAL people in your life?)  And wouldn’t you know, it actually makes a difference.  Losing a sliver of space around your home is a tiny compromise for the lifetime savings and added comfort.