Bard GSVS242-A, Руководство по установке

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Manual 2100-317J
Page
24 of 39
FIGURE 11
CLEANING WATER COIL
4. Scale Formation. Of all the water problems, the
formation of scale by ground water is by far the most
common. Usually this scale is due to the formation of
calcium carbonate by magnesium carbonate or
calcium sulfate may also be present. Carbon dioxide
gas (CO
2
), the carbonate of calcium and magnesium
carbonate, is very soluble in water. It will remain
dissolved in the water until some outside factor upsets
the balance. This outside influence may be a large
change in water temperature or pressure. When this
happens, enough carbon dioxide gas combines with
dissolved calcium or magnesium in the water and falls
out of solution until a new balance is reached. The
change in temperature that this heat pump produces is
usually not high enough to cause the dissolved gas to
fall out of solution. Likewise, if pressure drops are
kept to a reasonable level, no precipitation of carbon
dioxide should occur.
REMEDIES OF WATER PROBLEMS
Water Treatment.
Water treatment can usually be
economically justified for close loop systems.
However, because of the large amounts of water
involved with a ground water heat pump, water
treatment is generally too expensive.
Acid Cleaning the Water Coil or Heat Pump
Recovery Unit.
If scaling of the coil is strongly
suspected, the coil can be cleaned up with a solution of
Phosphoric Acid (food grade acid). Follow the
manufacturer’s directions for mixing, use, etc. Refer to
the “Cleaning Water Coil”, Figure 11. The acid
solution can be introduced into the heat pump coil
through the hose bib A. Be sure the isolation valves are
closed to prevent contamination of the rest of the system
by the coil. The acid should be pumped from a bucket
into the hose bib and returned to the bucket through the
other hose bib B. Follow the manufacturer’s directions
for the product used as to how long the solutions to be
circulated, but it is usually circulated for a period of
several hours.
LAKE AND POND INSTALLATIONS
Lakes and ponds can provide a low cost source of water
for heating and cooling with a ground water heat pump.
Direct usage of the water without some filtration is not
recommended as algae and turbid water can foul the
water to freon heat exchanger. Instead, there have been
very good results using a dry well dug next to the water
line or edge. Normal procedure in installing a dry well
is to backhoe a 15 to 20 foot hole adjacent to the body of
water (set backhoe as close to the water’s edge as
possible). Once excavated, a perforated plastic casing
should be installed with gravel backfill placed around
the casing. The gravel bed should provide adequate
filtration of the water to allow good performance of the
ground water heat pump.
The following is a list of recommendations to follow
when installing this type of system:
A. A lake or pond should be at least 1 acre (40,000 a
square feet) in surface area for each 50,000 BTUs of
ground water heat pump capacity or have 2 times the
cubic feet size of the dwelling that you are trying to
heat (includes basement if heated).
B. The average water depth should be a least 4 feet and
there should be an area where the water depth is at
least 12 to 15 feet deep.
C. If possible, use a submersible pump suspended in the
dry well casing. Jet pumps and other types of
suction pumps normally consume more electrical
energy than similarly sized submersible pumps.
Pipe the unit the same as a water well system.
HOSE BIB (A)
HOSE BIB (B)
ISOLATION VALVE
ISOLATION VALVE
PUMP