37 Evaluation and Improvement Proposals for a Business Facility …
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37.5.2 Geothermal Heat Pump Working Procedure
In the project discussed in this study, the capacity of geothermal HP was insufficient
and air conditioning problem occurred at store C. The use of a solar heat collector
was backed up by a hot water heater, but the air conditioning was entirely covered by
underground heat HP. The cost of retrofitting had greatly increased due to insufficient
capacity. To avoid such occurence, it is necessary to set a capacity exceeding the
predicted maximum load in the geothermal HP. This is in contrary to the example
of the solar heat collector. As mentioned earlier in Sect. 37.4.1, the geothermal HP
capacity had to be set to 75 kW. Furthermore, in addition to a simple calculation of
the total floor area, it is necessary to clarify the main load factors of the store and
consider the heat insulation performance of the building for capacity setting. It is
necessary to grasp the above points in advance, but in the modern days there are
many cases where land infrasctuctures are developed at a stage where tenants have
not come to decide on how to use the buildings. In order to make effective use of
renewable energy heat, it is necessary to set capacity systematically at the stage of
land infrastructure development, and to design it together with a tenant who will use
the facilities.
37.5.3 Utilization of Solar/Geothermal Hybrid System
In this project, it was worth noting that solar heat and underground heat were used
as a hybrid system, but as a result, the hybrid system did not work well, resulting
in a lack of capacity and surplus. As described above, the most important point in
solving this problem is that it is most effective to improve the accuracy of demand
prediction by organizing or setting tenant information to some extent at the stage
of land preparation. For example, if the load demanded by the tenant is known in
advance and the capacity is set properly, the installation cost of underground piping
will be reduced, the rise in the piping temperature of the underground thermal HP will
be eliminated, and the solar heat collector usage area will be reduced. It is clear that
by doing these steps unpredicted high costs can be avoided. Furthermore, since the
occurrence of air conditioning malfunctions and the cost of adding air conditioners
can be reduced for the demand side, it is considered that the tenant information in
advance is beneficial to both parties.
37.6 Summary
The following findings were obtained by data analysis of the solar heat/ground heat
hybrid heat supply system in the commercial facilities:
571
37.5.2 Geothermal Heat Pump Working Procedure
In the project discussed in this study, the capacity of geothermal HP was insufficient
and air conditioning problem occurred at store C. The use of a solar heat collector
was backed up by a hot water heater, but the air conditioning was entirely covered by
underground heat HP. The cost of retrofitting had greatly increased due to insufficient
capacity. To avoid such occurence, it is necessary to set a capacity exceeding the
predicted maximum load in the geothermal HP. This is in contrary to the example
of the solar heat collector. As mentioned earlier in Sect. 37.4.1, the geothermal HP
capacity had to be set to 75 kW. Furthermore, in addition to a simple calculation of
the total floor area, it is necessary to clarify the main load factors of the store and
consider the heat insulation performance of the building for capacity setting. It is
necessary to grasp the above points in advance, but in the modern days there are
many cases where land infrasctuctures are developed at a stage where tenants have
not come to decide on how to use the buildings. In order to make effective use of
renewable energy heat, it is necessary to set capacity systematically at the stage of
land infrastructure development, and to design it together with a tenant who will use
the facilities.
37.5.3 Utilization of Solar/Geothermal Hybrid System
In this project, it was worth noting that solar heat and underground heat were used
as a hybrid system, but as a result, the hybrid system did not work well, resulting
in a lack of capacity and surplus. As described above, the most important point in
solving this problem is that it is most effective to improve the accuracy of demand
prediction by organizing or setting tenant information to some extent at the stage
of land preparation. For example, if the load demanded by the tenant is known in
advance and the capacity is set properly, the installation cost of underground piping
will be reduced, the rise in the piping temperature of the underground thermal HP will
be eliminated, and the solar heat collector usage area will be reduced. It is clear that
by doing these steps unpredicted high costs can be avoided. Furthermore, since the
occurrence of air conditioning malfunctions and the cost of adding air conditioners
can be reduced for the demand side, it is considered that the tenant information in
advance is beneficial to both parties.
37.6 Summary
The following findings were obtained by data analysis of the solar heat/ground heat
hybrid heat supply system in the commercial facilities: