MSP VISIONS

GEOTHERMAL SYSTEMS USE RENEWABLE ENERGY	June/July 2008

Fossil fuels are non-renewable resources which release greenhouse gases that contribute to global warming. A movement is currently under way to find alternative, renewable energy sources that will relieve our dependency on fossil fuels, reducing our carbon footprint while still meeting our ever-increasing energy needs. One alternative source that can reduce energy consumption in a structure is a geothermal system. Geothermal systemsuse the temperature of the earth for the majority of heating and cooling. When compared to a conventional system, much less energy from non-renewable resources is required.
 
In layman’s terms, a geothermal system consists of heat pumps that use water or ground temperature, rather than air temperature, to heat or cool a building. The system often consists of pipes that circulate refrigerant through one of three ways; through wells drilled down to an aquifer, through a body of water (like a lake) or horizontally through the ground. In the winter, the refrigerant is warmed by the heat of the earth, pressurized to become superheated, and then used to heat the building. In the summer, the process is reversed.  The refrigerant is cooled to the ground or water temperature and brought directly into the building, where the refrigerant extracts heat from the air in the building.

While a geothermal system is initially more costly to install than a conventional system, the additional cost is normally offset by reduced energy bills. The geothermal system usually pays for itself in a matter of just a few years. In an age where energy costs are steadily increasing, geothermal systems make good, practical sense while at the same time providing an eco-friendly design feature.

The Savannah Center at Chappell Crossing, a new events facility in West Chester, Ohio, is an example of a structure that utilizes a geothermal heating and cooling system. Dan Montgomery, the MSP Project Architect who worked on the $12 million, 40,000 SF facility, recalls the client’s early interest in a sustainable site design. “Early in the design stages, the owners expressed an interest in using a geothermal system. An existing lake was viewed to be an excellent source of heating and cooling for the facility. A preliminary life cycle cost analysis showed that a geothermal system would pay for itself through reduced energy costs in merely 5.2 years.”

Two Waterstone Place, Miller-Valentine Group’s new Cincinnati Offices, is another project that utilizes a geothermal system. The facility is heated and cooled with the help of three plate heat exchangers, which are submerged below the basin of the lake on the site. Along with other sustainable features such as rain gardens, Tilt-up construction materials, and an energy-recovery HVAC system, the geothermal system shows Miller-Valentine Group’s commitment to sustainable design.

As a result of their decisions to implement geothermal systems, the owners of both the Savannah Center and Two Waterstone Place will be able to enjoy reduced energy costs well into the future. They also have the satisfaction of knowing that by creating a sustainable development, they are doing their part to preserve our environment.

For more information, visit the following links:

EERE's Geothermal Technologies Program
http://www1.eere.energy.gov/geothermal/

Geothermal Energy Association
http://www.geo-energy.org

Union of Concerned Scientists
http://www.ucsusa.org/clean_energy/renewable_energy_basics/offmen-how-geothermal-energy-works.html

Alliant Energy
http://www.alliantenergy.com/docs/groups/public/documents/pub/p012389.hcsp

Questions about geothermal systems or sustainable design in architecture? Call Craig Rambo, AIA, LEED® AP, MSP’s Chairman of the Board, at 513.759.0004.