Ground Source Heat Pumps

There are three basic types of ground source heat pumps – Water to Air, Water to Water, and Forced Air/Hydronic Combo units.

Water to Air – Forced Air Units

These heat pumps use the water in the loop field to bring the heat into the home. The heated water is run through an A-Coil on the furnace where air is blown over the coil to deliver the warm air to the building. Hence the name: water-to-air.

These heat pumps come in two configurations – Splits and Package Units

UMR Indoor Split

WaterFurnace Indoor Split

The split unit is designed to work in conjunction with a fossil fuel furnace. The split brings the water in from the loop field and raises it to a maximum of 130 degree. It then uses the blower and the A-coil on the fossil furnace to distribute the heat through the building

The Indoor split is the most common heat pump installed in residential buildings in Minnesota because it qualifies for ‘dual fuel’ programs offered by utility companies. Utilities will provide customers with lower price electricity to run their geoexchange system in return for the right to “control” the electricity during peak times. This allows the utility company to shut off the heat pump so that the system switches to the fossil fuel back up. This saves the customer and the utility company a great deal of money.

Packaged Units
UMR 7 Series

Water Furnace 7 Series

Packaged units contain the heat pump and the internal blower and fan motor. These systems are designed to totally eliminate the need for any fossil fuel furnace.

These units will also qualify for the dual fuel rates if they are controlled and have a fossil fuel back up. In most cases these units are backed up with an on-demand combination water heater and boiler. This eliminates problems with trying to tie in duct work and provides the additional advantage of lower water heating costs.


Water to Water – Hydronic units


Hydronic Unit

Hydronic units use water in the loop field to bring the heat into the home. They use water in radiant tubing or radiators to deliver the heat to the home.

Hydronic units provide super-efficient hot water generation for radiant infloor heating, traditional radiators, pool/spa heating, snow melt, aquaculture and other applications.

A major limitation of Hydronic units is that they cannot do air conditioning because they have no duct work system.

Combo Units – Forced Air/Hydronic (water)

UMR Synergy

WaterFurnace Synergy

More and more home builders are using the combination of hydronic and forced air systems to achieve maximum comfort and performance. A home may have in-floor radiant heat in the garage, basement, and bathrooms to provide warm floors and maximum comfort. The balance of the home uses force air to provide maximum circulation and to handle air conditioning.

The Combo units can provide both hydronic capability for in-floor radiant heating (water to water) and forced air capability for heating and air conditioning (water to air).

These units can qualify for dual fuel rates with the addition of a fossil fired boiler or on-demand boiler/water header combination unit. The boiler can provide hot water to back up the hydronic and the forced air system.