Standing
Column Well System. Standing column wells, also called turbulent wells
or Energy WellsTM, have become an established
technology in some regions, especially the northeastern United States. Standing wells are typically six
inches in diameter and may be as deep as 1500 feet. Temperate water from the
bottom of the well is withdrawn, circulated through the heat pump’s heat
exchanger, and returned to the top of the water column in the same well.
Usually, the well also serves to provide potable water. However, ground water
must be plentiful for a standing well system to operate effectively. If the
standing well is installed where the water table is too deep, pumping would be
prohibitively costly. Under normal circumstances, the water diverted for
building (potable) use is replaced by constant-temperature ground water, which
makes the system act like a true open-loop system. If the well-water
temperature climbs too high or drops too low, water can be "bled"
from the system to allow ground water to restore the well-water temperature to
the normal operating range. Permitting conditions for discharging the bleed
water vary from locality to locality, but are eased by the fact that the
quantities are small and the water is never treated with chemicals.
