A 6,340 square foot (589 m2) addition to the 4,000 square foot existing building was made in 2004. The peak cooling load created by the large number of occupants during a church service (378 kBtu/hr or 110 kW) is much greater than the peak heat loss in the building the rest of the week (121 kBtu/hr or 35 kW).
The large imbalance between the peak heating and cooling loads led to an innovative solution in an effort to reduce the size and cost of the GHX and GCHP equipment. Selecting heat pump equipment to meet the peak heating load left a shortfall of approximately 257 kBtu/hr (21 tons or 75 kW) to meet the peak cooling requirement of the facility.
For most of the week there is little activity in the facility, and the cooling load is minimal. Using the heat pumps to build ice in an ice storage tank during the week reduces peak heat rejection to the GHX. During peak cooling loads, a percentage of the heat from the building is rejected to the ice storage tank rather than the GHX.
The size of the GHX was reduced from 4,500' (1,360 m) to 2,400' (730 m) ...a reduction of 50%. Heat pump capacity was reduced from 27 tons (95 kW) to 12 tons (42 kW). Peak electrical demand of the facility was reduced by 10 kW.
Additional technical information about the integration of energy storage with a GCHP system can be found in the ASHRAE Journal article, April, 2013.
Geothermal design: Ed Lohrenz, Ice Kube Systems
Project completed: 2004
The large imbalance between the peak heating and cooling loads led to an innovative solution in an effort to reduce the size and cost of the GHX and GCHP equipment. Selecting heat pump equipment to meet the peak heating load left a shortfall of approximately 257 kBtu/hr (21 tons or 75 kW) to meet the peak cooling requirement of the facility.
For most of the week there is little activity in the facility, and the cooling load is minimal. Using the heat pumps to build ice in an ice storage tank during the week reduces peak heat rejection to the GHX. During peak cooling loads, a percentage of the heat from the building is rejected to the ice storage tank rather than the GHX.
The size of the GHX was reduced from 4,500' (1,360 m) to 2,400' (730 m) ...a reduction of 50%. Heat pump capacity was reduced from 27 tons (95 kW) to 12 tons (42 kW). Peak electrical demand of the facility was reduced by 10 kW.
Additional technical information about the integration of energy storage with a GCHP system can be found in the ASHRAE Journal article, April, 2013.
Geothermal design: Ed Lohrenz, Ice Kube Systems
Project completed: 2004
