Crystal Air P.O. Box 1501 Weaverville, CA 96093 1-530-623-1000 California State License Board #762833
Geo Exchange (GeoThermal)
Geo Exchange is quite simply, heating and cooling utilizing the earth itself as a source of energy.
"More dependable and constant than Solar"
By going five feet down in the ground, we can tap into a consistent 55 degree thermal zone in the earth. It doesn't matter if it is sunny outside or not. Intuitively, most everyone will realize the tremendous boon and application of that temperature zone for air conditioning but, there is more than that. In order to understand the benefit for heating applications, we need to spend a little time explaining the concept of a Heat Pump.
Here's How It Works
* Any time the temperature is above -459 degrees Fahrenheit (absolute zero), there is heat in the air .
* Technically, an air conditioner does not put "cold" into a house. In actuality, it "moves" the heat inside the house to the outside air and therein, makes the home cooler.
Plugging in to Free Renewable Energy
By circulating water via tubing in the ground or a pond (known as a loop), we can tap into that constant and manageable temperature and, attach it to a unit to heat and cool a home or business. Now, instead of an air source heat pump, we have a ground source heat pump. The net effect is that for every unit of electricity we use to drive the system, we can get back up to 5 times more energy than we put in. To compare, an air source heat pump (or air conditioner for that matter) will only return us up to 200% more than we invest. The net result is an energy savings of 50% -60% or more! Click here to read the US Department of Energy analysis of GeoThermal (Geo Exchange).
Geo Exchange installations have proven to cut your utility costs by 50%-70% due to their efficiency over conventional units. Over a 30 year mortgage, that's BIG BUCKS! Geo Exchange is an additional upfront investment for installation but, even with the added installation costs, customers often see a return on investment in as little as five years.
30% Federal Tax Credit for Geo Exchange Installs
The primary cost difference is in the implementation of the "loop" or piping conduit installed in the ground or pond through which we will circulate water to pick up that ever renewable temperature stored there. The "loop" is a one type investment though. Quality manufacturers will warranty the loop conduit for 50 years and the capacity for its viability beyond that is still unknown. On the equipment side (condenser, coils etc.) the accepted estimated lifetime is 25 years (typical warranties are for 10 years) This compares with air source heat pumps and air conditioners that have a life expectancy of only 15 years . There is GOOD NEWS! though, The Federal Government offers a 30% Tax Credit for installation of GeoThermal systems.
Geo Exchange is a proven and dependable technology if installed by trained and qualified experts that can size, configure and integrate a system correctly. Expertise in knowing what type of loop and how to execute it is essential for success and a lifetime of dependable heating and cooling. That's an important point to consider when selecting a contractor for a Geo installation. Reputable contractors for conventional heating & cooling installation should know and use the correct calculations for determining the "load" for equipment that your home requires and all the current codes (read more here) but, the specialized equipment for Geo and the loop make it a unique level of craftsmanship.
A horizontal loop tends to be the least expensive for installation but,
also tends to be the least used due to it's requirement of space.
Trenches are dug at a depth of 5 feet in a closed ccircuit or series of circuits
and, a loop of supply and return polyethylene (pde) tubing is strung
throughout the trenches. A good rule of thumb for the space requirements
to install a horizontal loop is 6,000 square feet per "ton" of heating and cooling requirement. The average U.S. home will require between 2.5 and 5 tons
of capacity or, between 15,000 and 30,000 square feet of unobstructed and flat
land space for implementation.
Vertical Loops tend to be the most common loops, especially in urban
settings where space is limited. Vertical loops have two sub categories,
short bore and long bore. Short bore loops are very economical and are
comparable to horizontal loop costs. Short bores are drilled in a radial pattern
to a depth of 20 feet each and tied together with a trenched manifold again,
at a depth of 5 feet. Long bores are for very tight spaces and can be drilled
to a depth of 300 feet. In both long bore and short bore configurations,
closed polyethylene supply and return lines are inserted and holes are
backfilled with bentonite clay for a good cohesive thermal bond to the ground.
Trench lines from the vertical bore field are also dug to the house to connect
the loops to the unit inside the home. Even in the case of more costly long
bore vertical loops, home owners can frequently see a reduced utility cost
return on investment in as little as 6 years.
Typically the least common type of loop for obvious reasons, pond loops
are very economical and very efficient. Two general approaches are often
used. One would be to lay and afix a coil of polyethylene supply and
return tubing to the bottom of the pond. The other approach uses a
metal "radiator" unit that can be affixed underneath a dock or pier.
Again, 5 foot deep trenches are dug from the pond loop to a the home or
building. The cost efficiency of pond loops is due to their relative ease
of installation and in part due to the fact that they are in direct contact
with the excellent thermal conductivity of water. Details for the size
requirement of a pond loop are more complex than can be explained
here but, as a guiding minimum measure to qualify whether or not your
pond is feasible for installation, a pond depth of at least 10 feet and
surface area of 25,000 square feet is necessary.
Like an air conditioner, a heat pump can
move hot air from inside the house to the
outside air in the summer via copper
tubing filled with refrigerant. In the winter,
by reversing the mechanics, it can take
heat from the outside air and move it to
the inside and warm the home.
"Heat Pumps. The Future of Heating and AC"
The first heat pump was invented in the 1850’s
and is widely used throughout the US
accounting for half of all new heating
and air conditioning units sold in 2010.
However, the one difficult to overcome
drawback to Air source heat pumps is
that when we need them to work the
hardest is when they are the least efficient.
As the winter sets in and the air gets colder,
it becomes more difficult to extract heat
from it. In the summer, as the air gets
warmer,it becomes more difficult to
disperse heat from inside to the outdoor
air. If we have a more consistent and
median source for moving heat to or from,
we can greatly increase efficiency.
Types of Closed Loops
Geo Exchange- Going beyond.
Wherever you have a need or desire for heating or cooling, Geo Exchange works.
In addtion to heating and cooling needs, a Geo Exchange system can be configured to support all your hot water needs, a pool heater, wine rooms, walk in coolers, de-icing of your driveway and more!
The links provided are for your further education and awareness of unique and large scale applications that have plugged into the earth with Geo Exchange.
An open loops refers to directly exchanging water to the system with a water resource in the ground instead of a closed conduit circuit. Examples of this type of loop would be openly pumping water to and from a pond or a subterranean well. Due to enviromental concerns and the need for expensive lengthy impact studies, this type of loop configuration is very rare or not permissible.