Variable-Speed Compressor Technology Geothermal Heat Pump

Last year, geothermal heat pump (GHP) manufacturers introduced new heat pumps with break-through efficiency based on variable-speed compressor technology. These manufacturers include Waterfurnace Renewable Energy  and ClimateMaster, a division of LSB Industries

As someone who has been enjoying the geothermal evolution I could not be more excited to finally see variable speed technology begin to try and grow some roots in the marketplace. In 1984 I had the privilege, while working at Carrier, to actually have in my house in Central New York, what I believe was the first variable speed compressor operating in a geothermal system. Using a Carrier Triple Split Heat Pump, a Hitachi Inverter, and various R&D Products developed by Roger Voorhis et al, we achieved EER’s & COP’s that were “off the charts” at that time.

However, I hope the manufacturer’s do not get all caught up in maximizing the value that is part of “the box” they are providing, simply to justify the extremely high price tag. As we work with various high end residential clients who not only expect “the best”, they demand it. Having a heat pump that comes from the factory with everything (just shy of including the kitchen sink) it makes it very difficult to incorporate into a overall system design that truly delivers the best system. It is THE SYSTEM that has to be the best, not just the heat pump, and every system has a unique set of requirements, from pool heating, snow melting, domestic water heating, incorporate solar thermal, not to mention heating and cooling.

Consequently, I would like to challenge all the heat pump manufacturer’s to provide the best system component – a variable capacity, high temperature, simple water-to-water heat pump that would exude maximum flexibility without trying to dictate from the factory system design philosophies.

California Residence Heated and Cooled by Geothermal Heat Pump

One of the largest homes in Northern California is owned by Frederick Corson’s . He is proud with the very low heating and cooling bills. 

Carson fitted his residence with a ground-source heat pump known as a geothermal heat pump. The pump and pipe installation are environmentally friendly and sustainable, while they also keep the costs of heating and cooling the house minimal. This whole system works on the principal that regardless of the temperature on the Earth’s surface, it is always 60 degrees a few feet underground. 

California Residence Heated and Cooled by Geothermal Heat Pump

A geothermal heat pump is installed by first drilling holes 200 to 300 feet deep and then inserting U-shaped tubes into them. These earth-heat exchange tubes are then connected to a primary heat exchanger.  The tubes are filled with a solution of water and alcohol, which prevent corrosion and freezing.

The owner of the 5000 square foot home in California turn on this heating system in November and and keep it on through April. In the summer, the geothermal heat pump system can also be reversed to cool the house. To do this, the pump pulls the warm air out of the house and transfers t into the ground.