Delivery Systems

There are differences in how conventional and GeoExchange systems deliver a conditioned environment to your home:



1 speed – off or high
Every time the furnace comes on, it gives the maximum amount of heat and blower speed, no matter how much heat is needed. This results in:

  • Reduced efficiency
  • Increased costs
  • Temperature overruns, especially in spring and fall
  • Hot and cold spots throughout the house
Staged Heat Pump and Blowers
Heat pumps and blowers run in two or more stages. This results in:

  • Increased efficiency as the system delivers only what is needed
  • Reduced costs due to increased efficiency
  • Eliminates temperature overruns
  • Longer cycle runs hold temperature within two degrees of the thermostat setting
  • Eliminates or minimizes hot and cold spots
Fuel Storage
Delivering and storing oil and propane creates safety hazards and increased maintenance as they have to be stored at the residence.
Natural Storage
The energy for a geoexchange systems is stored in the earth.
Combustion No Combustion
The combustion for a geothermal system was done by the sun and stored in the crust of the earth. Therefore there is no storage or burning of hazardous material.


Forced Air

Water-to-Air heat pumps use a forced air system to deliver to and remove heat from a building.

In a forced air system, a blower moves air through a system of ductwork. The “supply runs” in the ductwork go out from the furnace or heat pump to deliver warm air to the building. As the supply runs bring air into a room, the “return runs” bring air out of the room and back to the furnace or heat pump. Whenever the blower is running, there is a constant movement of air throughout the building.

In the heating season, the ground source heat pump circulates water through a heat exchanger called an A-Coil that sits in the plenum chamber above the furnace or heat pump. As the blower moves air over the A-coil, it absorbs the heat and carries it through the ductwork to the rest of the building. In the cooling season, the process reverses. The A-Coil absorbs heat out of the warm air in the building and passes it down into the loop field where it is absorbed by the ground.

Minimum Ductwork Size

Geoexchange requires 400 cfm (cubic feet per minute) for every one ton of geothermal capacity in order to run efficiently and quietly. If the cfm is less than 400, the ductwork will create resistance and build up pressure inside the ductwork. This pressure can create noise and give the system “high blood pressure” that puts stress on equipment resulting in increased maintenance and repairs.

Ductwork is often an issue in retrofit homes. Many builders have tried to save money by undersizing the ductwork and putting in an oversized furnace and blower to push the air through the system. These systems often make a very audible “whomp!” sound when the blower comes on and the ductwork expands under the pressure. To install geoexchange in these situations often requires a significant amount of remodeling to allow for modified or replacement of the existing ductwork.

Radiant – Hydronic

UMR_RadiantHydronic“Water-to-Water” ground source heat pumps (GSHP) are hydronic units. They deliver heat to a building using hot water that goes through radiators or in-floor tubing. The heat from the hot water “radiates” out from the delivery system to heat the building.

Radiant In-Floor

Radiant in-floor heating is one of the most comfortable delivery systems for heating a building. Radiant floors circulate warm water through tubing embedded in the floor of the home. The heat radiates up through the floor, warming the furnishings and air in the room. The warmth stays down around where the people are, not up at the ceiling or lost to the outdoors every time a door or window is opened. It’s a comfortable, even heat where cold spots and drafts are eliminated.

The Benefits — Feel Them to Believe Them
  • True comfort – Imagine your beautiful floors are now warm and cozy to the touch.
  • Works everywhere – Under tile, marble, wood, carpet and concrete floors. Radiant walls and radiant ceilings can also create a cozy, efficient environment.
  • Saves money – Can save 20 to 40 percent on energy costs compared to traditional heating systems.
  • Clean, healthy – No drafts or fans blowing dust, dirt and other allergens into the air.
  • Quiet – No noisy fans, popping ductwork and pinging pipes.
  • Increases enjoyment living space – Lets you live in and enjoy that previously cold basement.
  • Wise investment – Makes your home more attractive to potential buyers.

UMR_RadiatorsBoth cast iron and aluminum baseboard radiators require high temperature water to operate efficiently. This has historically been a problem for ground source heat pumps that can reach only 130 degree temperatures. But this is changing with WaterFurnace’s introduction of “vapor injection technology” into the US market. This technology will allow ground source heat pumps to routinely reach the 150 degree range efficiently and effectively.

No Air Conditioning

A down side to radiant heating is its inability to deliver cooling to a home. The radiant system cannot be reversed to pull heat out of the home without condensation.  So if air conditioning is desired, it should be done through an additional system and equipment.

Electric Resistance

Electric resistance heating uses the heat generated by the resistance to an electrical current flowing through a conductor. Since geoexchange does not generate electrical current it will not work with these systems unless there is also ductwork or hot water radiant also available.