Going underground for cooling using geothermal technology

When it opened in 2016, Kimpton Seafire Resort + Spa became the first Dart property to provide air conditioning via geothermal cooling technology. Last month, Camana Bay started a two-year geothermal project to do the same.

With more than a million installations across the United States and a handful of commercial applications locally, like the Government Administration Building and Foster’s supermarket, geothermal has become a widely recognised and environmentally friendly method of air conditioning. Here’s how it works: 

Most people assume that air conditioning just requires pumping cool air into a building, but that’s actually missing a step. First, an effective air conditioning system removes heat from the space. But where does that heat go?

In a geothermal system, heat is removed from buildings using chilled water air handlers and then absorbed in the ground as it exits the condenser. As the earth is at a lower temperature (generally 78⁰F year-round in Cayman), the water from the condenser discharge is easily dispersed into the earth.

Benefits

Geothermal cooling offers several advantages:

  • Efficiency. Instead of using energy to cool condensing water down to 78 degrees, the system uses underground water that is already cool. This saves water and electricity, and allows the system to operate more efficiently all year round because it is not impacted by outside air temperature or humidity fluctuations.
  • Reduced emissions. Geothermal technology also doesn’t require conventional cooling towers and their associated energy costs. This leads to a 15% reduction in fossil-fuel generated energy — that’s 15% less carbon going into the atmosphere.
  • Cost savings. In addition to the immediate cost savings associated with the 15% reduction in electricity usage and its subsequent utility bill, geothermal systems also offer long-term cost savings because they require less maintenance than conventional cooling systems, do not depend on the production of expensive reverse osmosis water and need no chemicals to treat tower water.

Dart Director of Property Operations Chip Ogilvie is one of the leaders on the Camana Bay project to convert its existing cooling plant into a geothermal plant. “As always, we’ve taken a long-range outlook, which is why the plant design is modular," he says. "This allows us to install the capacity required for the short term and add more cooling capacity as our cooling load grows.”

The Camana Bay geothermal plant is scheduled for completion in 2023, complementing the master-planned community’s other renewable energy applications like solar panels, glass recycling and environmentally friendly LED lighting.

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This article appears in print in the April 2021 edition of Camana Bay Times, written by Annika Martins.

 

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