Bard GV27S1-A, Руководство по установке

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Manual 2100-510E
Page
22 of 38
FIGURE 11
CLEANING WATER COIL
MIS-2624
Pump
Hose Bib (A)
Hose Bib (B)
Isolation Valve
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 but 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 water loop systems. However,
because of the large amounts of water involved with a ground
water system, 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 solution is 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
refrigerant 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 at least 4 feet and
there should be an area where the water depth is at least
12 to 15 feet deep.