As part of the ground source heat pump at Curry Village employee housing, glycol fluid flows through the geo-field plastic pipe network. The project has saved thousands of dollars in heating bills.

How has Curry Village housing gone 'green'?

The new Curry Village employee housing area, completed in 2007, incorporates an environmentally friendly and highly efficient heating and cooling system called a ground source heat pump (GSHP). The system utilizes the near constant temperature of the earth to keep the buildings heated and/or cooled. A glycol and water mixture is pumped through a “geo-field”, which consists of a network of plastic pipes installed vertically in deep bore holes in the ground. In 28 buildings at Curry Village, this geo-field is comprised of 178 bore holes, each 280-feet deep, all tied together in a loop configuration. The glycol fluid exchanges heat between the buildings and the earth by means of electrically-powered heat pumps located inside the residential buildings. In winter, warmth is drawn from the Earth and exchanged with the buildings. In the summer, the process is reversed; heat is extracted from air inside the buildings and transferred to the ground by means of the glycol fluid that flows through the loops in the geo-field.

Finished employee housing at Curry Village in Yosemite National Park won a 2008 award for its green efficiency.

How Does a GSHP System Compare?

The Environmental Protection Agency (EPA) has found that GSHP systems are the most energy-efficient, environmentally clean, and cost-effective space-conditioning systems available. The EPA also found that these heat pump systems offer the lowest carbon dioxide emissions and lowest overall environmental cost of all the residential space-conditioning technologies readily available today. The few emissions that are released occur at power plants, where they can be more carefully monitored and controlled.

The Yosemite National Park Curry Village Design Team has won a 2008 Environmental Achievement Award in recognition of the sustainable design features of the new employee housing complex for Curry Village (which implements Yosemite Valley Plan replacement of facilities destroyed in the 1997 flood). The design of the new complex, made up of 28 buildings that house 217 people, incorporates exemplary site selection, mechanical systems, lighting, and water efficiency features. The National Park Service presents Environmental Achievement Awards each year to parks and concession companies that have excelled in incorporating high environmental standards into their operations. The award criteria emphasize sustainable design as well as systems and programs promoting energy efficiency, water conservation, materials recycling, and other earth-friendly, cost-saving features. 

Glycol fluid exchanges heat between buildings and the earth by means of electrically powered heating and cooling pumps (shown here) located inside the residential buildings.

What Are the Technological Benefits?

There are many advantages to using this ground source heat pump system as opposed to other alternatives. Some of them are:

• Very low heating and cooling costs—approximately 40 percent less than the next best technology
• Excellent comfort and humidity control
• Quiet operation minimizes noise pollution
• No air pollution added to the park
• No need to purchase, transport or use propane
• No mechanical equipment is located outdoors—enhancing the visual aesthetics

Read the park's a ground source heat pump fact sheet [68 kb PDF].