Geothermal Solutions

There are two types of systems used for geothermal heating and cooling: vertical and horizontal. Horizontal loops are most often used in New England due to the increased possibility of encountering ledge (extremely hard rock that typically must be removed using explosives, a dangerous and expensive proposition). The following information outlines various considerations when choosing geothermal to heat and cool your home.

Here are examples of the two types of systems.

Horizontal Loops

Though there are other systems, these are the two most frequently used systems in the New England area:

Slinky Loop		Pond Loop

Vertical Loops

Additional Considerations

• Home insulation value: The doors and windows should have a high U value. The type and amount of exterior, attic, roof, and floor/slab insulation. Venting and exterior landscaping will affect the total insulation value. Bottom line: less insulation requires more heating/cooling.
• Cubic square feet of your home.
• Heating/cooling load averages in New England.
• Expected hot water production.
• May need a Solar PV panel to supply the heat pump system if not using public utilities.
• The type of existing heating system. Retrofits for existing systems vary widely and will need careful consideration.
• System options such as, domestic hot water production (heating hot water as well as your home)
• Excavation complications (e.g., ledge, shale or dig safe alerts) need special consideration
• Soil Type. The ideal soil type is saturated sand & gravel. The least ideal is loose, dry soil.

The Bottom Line