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Bosch Geothermal Heat Pumps
Bosch Thermotechnology Corp.
Data subject to change
Applications Manual
14.4 General Flow Center Criteria
The pressure drop of the entire ground heat exchanger
should be calculated for the selection of the ow center.
In general, if basic ground heat exchanger design criteria
is followed, units of 3 tons or cooling capacity or less will
require only one (1) circulating pump. Units from 3.5 to
6 tons of cooling capacity will normally require a two (2)
pump ow center.
Loop pressure drop calculation should be performed for
accurate ow estimation in any system including unit, hose
kit, inside piping, supply/return headers, circuit piping,
and ttings. The Bosch Geo Solutions software program
will help in determining the ground heat exchanger
pressure drop for accurate ow estimation.
Regardless of the use of either a pressurized or non-
pressurized ow center, it must be located between
the Bosch geothermal heat pump and the ground heat
exchanger. Additionally, the ow center should be located
as closed to the Bosch geothermal heat pump unit as
possible to limit the length of hoses and associated
pressure drop. Ease of future service should always
be considered as well when determining ow center
placement.
Fig. 109
Ground heat exchanger piping is typically polyethylene
piping directly into the ow center. These connections
can be made with either a fusion or barbed tting. Other
materials may also be used for this connection such as
copper piping. Additionally, installers may also install
commercially available optional ow meters as well (Fig.
109). This tool is used determine the actual GPM owing
through the system.
