FACT: Geothermal systems provide the most efficient, comfortable and environmentally friendly method of heating & cooling.

Geothermal HVAC Glossary of Terms

EER (Energy Efficiency Ratio)

The ratio of cooling provided by a geothermal heat pump to the energy it consumes. Higher EER equals higher efficiency.

COP (Coefficient of Performance)

The ratio of heating provided by a heat pump to the energy it consumes. Higher COP equals higher efficiency.


The compressor increases the pressure and temperature of the refrigerant and simultaneously reduces its volume while causing the refrigerant to move through the geothermal heat pump to facilitate heat transfer between the air in your home and the heat pump. ClimateMaster offers geothermal heat pumps with compressors that are either 1 or 2-stage. 2-stage compressors are more efficient than their 1-stage counterparts.

Water Flow Control

 In order for a geothermal heating and cooling system to exchange heat via its underground loop, water must be continuously circulated between the ground and the heat pump. This is the job of the water flow control. ClimateMaster offers 2 different water flow control methods in its geothermal heat pumps:

vFlow® Internal Variable-Speed Water Flow Control

vFlow® builds the major water circulation components into the heat pump for a cleaner, smaller installation and intelligently varies water flow to minimize pump energy consumption. This is ClimateMaster’s most energy efficient water flow option and is currently available only in the Tranquility® Digital Series.

External Fixed-Speed Water Flow Control

This is the traditional method of water flow control in which fixed (single-speed) pumps are housed outside of the heat pump. This method of water flow control requires a bit more space to install and is not as efficient as vFlow®.

Indoor Fan

The indoor fan is responsible for circulating conditioned air throughout a home’s air conditioning ductwork and is housed inside of the heat pump. ClimateMaster heat pumps are currently offered with 2 types of indoor fans:

Variable Speed Indoor Fan

ClimateMaster’s variable-speed indoor fan intelligently varies fan speed to minimize energy consumption. This is ClimateMaster’s most efficient indoor fan option.

Single Speed Indoor Fan

The single speed indoor fan operates at only one speed. It gets the job done but is not as energy efficient as the variable speed fan.

Electronic Controls

The electronic controls are the brains of a ClimateMaster geothermal heat pump. They control all aspects of unit operation and receive and translate information from the thermostat. ClimateMaster geothermal heat pumps are currently offered with two types of electronic controls:

iGate® Communicating Controls

iGate® Communicating Controls allow for 2-way communication between the thermostat and heat pump and analyzes the status of sensors and other 2-way communicating components to determine how best to operate your system for optimal comfort, efficiency, and long term reliability. iGate® technology represents the next generation in intelligent controls and will allow for future accessories to access and control your system via internet devices. iGate® controls are available only in the Tranquility® Digital Series.

Non-Communicating Controls

These are traditional electronic controls that do not support 2-way communication. These will get the job done but are not able to control geothermal system operation as efficiently as iGate® communicating controls.