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Vertical Ground Loops
Vertical ground loops can fit in to tighter spaces because they require less area than a horizontal ground loop. The first two pictures show the drlling rig, which in this case is owned by a drilling contractor. Drilling contractors are usually hired to drill the boreholes. This back yard area was used to install a four-loop system at a house in North Portland. Loop depth's can range from anywhere between 130 to 200 vertical feet Loop's are typically closed just as in a horizontal loop with a water-antifreeze solution for the fluid. Vertical ground loops tend to be more expensive due to the type of equipment involved, but with fuel prices rising they will still pay back in the long run. Delta-Montrose Electric Association, of Montrose CO, recently started a program that offers financing of the ground loop portion of a geothermal heat pump system. The ground loop can often account for as much as half of the installation costs of a geothermal system. It is likely one of the first programs of its' kind anywhere in the country. But with natural gas prices beginning a steady and upward climb for the indefinite future, more innovative programs like this are likely to occur in other parts of the country. For more information read the Delta-Montrose Electric Association press release located below. Horizontal Boring A recent
technology that shows great promise to
significantly reduce the cost of installing ground loops is horizontal
boring, or directional drilling, as it is often known. With
horizontal boring the footprint of the ground loop is minimized because
the loop is 'bored', as opposed to trenched or drilled, in to the
ground. It Installation costs for a horizontal boring system are typically one-fourth that of conventional vertical drilling systems. It combines the best attributes of conventional horizontal and vertical types of systems: it minimizes the footprint and excavation of the ground loop but it's much less expensive than installing a vertical system. For homeowners with small lots or extensive landscaping, horizontal boring or directional drilling could be viable option for getting the high efficiency heating and cooling of a geothermal heat pump system. Geothermal Heating
Systems There
are two primary types of heating systems used with geo-exchange heat
pumps including, forced-air and radiant floor systems.
Forced-air
systems are the most common because they use standard duct work to
transport conditioned air through out the home. Radiant floor
systems are much more efficient and comfortable
because
they actually heat the floor rather than the air, so it is possible to
maintain a lower temperature and still remain comfortable.
Since
warm air rises they maintain a more relatively constant temperature and
they don't produce huge blasts of hot and cold air. They do
require a ventilation system because heating the floor does not
provide fresh air. They also typically require a separate
cooling
system. Geo-exchange forced air systems on the
other hand,
are capable of providing both heating and cooling. This is
because they use a duct work system to distribute conditioned air. Geo-exchange Heat Pumps work in much the same way as a refrigerator. Rather than generating heat through the combustion of fossil fuels, a heat pump merely transfers heat back and forth between the ground and the building. The earth is constantly absorbing energy from the sun so it acts as a heat sink, or repository of heat for future use. In the winter the heat pump extracts heat from the ground, and in the summer the process is reversed by rejecting heat back to the ground. Because there is no direct consumption of fossil fuels and because it uses the equivalent of approximately ten 90-watt light bulbs in electricity, a geo-exchange heat pump is more efficient, cost-effective and more beneficial for the environment than natural gas or oil-fired furnaces. According to the US Dept. of Energy, 40% of all CO2emissions come from space heating and cooling. That's almost as much as auto emissions. The basic concept of geothermal heat pumps, the transfer of heat between the earth and buildings, is illustrated with the following graphic.
 In addition to geothermal heat pumps we also sell tankless water heaters, heat recovery ventilators and electric radiant floor systems. Geo-exchange heat pumps provide comfortable space heating and cooling, and they can also be used to heat domestic hot water. Geo-exchange heat pumps are electrically powered systems that transfer heat back and forth between the earth and your building. The reduction in CO2 emissions is also significant because heat pumps do not burn fossil fuels. A geo-exchange heat pump must be installed by a licensed contractor in order to qualify for energy tax credits. More
information on geothermal heat pumps, renewable energy and
energy efficiency:
(requires Adobe or Flash Player) Geothermal Heat Pump Information
Survival Kit -
Oregon Institute of Technology Geo-Heat Center
Modern Heating & Cooling for
Historic Structures - Geothermal
Heat Pump Consortium |
is also
much less expensive than vertical drilling because the equipment is
much smaller, so it can also fit in to much smaller spaces
than conventional
drilling equipment. Loop depths are typically 150 to 200' and
they do not require the substantial amount of excavation associated
with regular horizontal ground loops. The picture on the left
illustrates a typical horizontal boring unit.
