AM, EM, AQ, BA, ASW - IOM
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Ing.Ji
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4 Ground Loop for AQ units
4.1 System Description
This natural resource exploits accumulated solar energy. During the summer the earth surface
is warmed by solar energy. In winter we withdraw this energy and using the heat pump we use it
for heating.
For this, a system of exchangers must be built. Anti-freeze mixture circulates inside the
exchangers. It is thus a so-called closed system and the circulatory pump ensures circulation of
the anti-freeze mixture. The earth exchangers are made from polyethylene pipes PE32, or
PE40. There are several types of earth exchangers.
4.2 Horizontal Ground Loop
This is a planar collector with piping evenly distributed over the required area of land. The size
of the collector system and thus the needed area of land depend on the heat loss of the building
– power of the heat pump and the heating capacity of the soil. Following table lists approximate
values of various types of soil.
Type of soil
Yield on m
2
of land
Area needed for 1kW of building
peak heat demand
dry, non-cohesive
10W/m
2
70m
2
moist, cohesive
20÷30W/m
2
40÷26m
2
wet loose
35W/m
2
20m
2
The main requirement of the collector systems is the same length and diameter of all loops to
ensure the same flow through all loops.
Building permit is required for building the earth
exchanger.
4.2.1 Standard Horizontal Loop
This type is based on even distribution over the entire area of land. It is suitable for any shape
of land. The piping is placed 60cm under the frost depth, that is 1,5 to 1,8m depending on the
location. The spacing of the piping is to be 60 to 80cm, maximum 100cm.
1,5-1,8m
sand bed
loop piping
60–80cm 60–80cm 60–80cm
Standard horizontal ground loop configuration.
