The movement of heat energy to and from a building is important in the heating and cooling process. A properly engineered geothermal system takes into account the entire building from the standpoint of heat sources and sinks, and efficiently moves heat that already exists throughout the building.
It is commonly understood that geothermal systems move heat from the earth to the building when there is a heating need and from the building to the ground during cooling. However, there are other ways heat can be moved around that maximize energy savings and often reduce the overall system’s capital costs. Do you know how that’s done?
Most commercial buildings are cooling dominant. This means that over the course of a year there will be more heat energy rejected than absorbed. If the amount of heat rejected can be balanced with what will be needed later, the size and cost of the outside heat exchanger can be greatly reduced.
How can this excess heat energy be used? Many commercial buildings have a significant need for domestic hot water – including bathrooms, locker rooms, kitchens, and laundry. Geothermal heat pumps can use the heat absorbed from space conditioning to generate nearly free hot water. Why buy more energy to produce hot water when excess heat energy is being wasted?
Additionally, excess building heat energy can be used to generate the hot water needed for radiant and snow melt systems. With radiant systems, heat can be moved from the core areas of a building, where cooling may be required year-round, to the perimeter areas of the building where there may be heat loss through walls and windows. With snow melt systems, the excess heat energy can be used to melt snow and ice on sidewalks and driveways.
In situations where a building is heating dominant, there may be additional opportunities to capture heat and move it to the building for space conditioning or hot water generation.
When excess heat energy is generated, but not immediately needed, it can be moved to the ground and stored for later use. What kinds of heat movement does your building need? Are you taking advantage of this free resource?