FOR IMMEDIATE RELEASE
(Boulder, CO 7/26/2007)
Now in their second summer living in Solar Harvest, Eric Doub and his family continue to appreciate the value of a well-insulated, finely “tuned” home for year-round comfort, with zero annual energy bills. During the winter, airtight construction and superior insulation were recognized as the key features creating the “charge and coast effect” by which the home passively gained, and retained, solar heat during several consecutive cloudy cold-snap days. Now in summer, it is apparent that these features, along with ample south overhangs, are also responsible for the home’s ability to maintain cool indoor temperatures. “We have been amazed at how the house will be 75˚F at 3pm when it is 95˚F outside. Our first summer here it was astonishing in how well the nighttime coolth held through the hot days,” said Eric.
Completed in November, 2005, Solar Harvest is the City of Boulder’s first net-zero energy home and possibly the first in the nation approved under modern code for construction in a cold climate without a fossil fuel- or wood-burning back-up heater or hot water boiler. Outfitted this spring with a variety of web-based monitoring devices, Solar Harvest serves as an educational tool for learning about homebuilding in Colorado. The live energy monitoring website is publicly accessible at: www.ecofuturesbuilding.com/systemsmonitoring.
Fitting its educational identity, Solar Harvest inspired the question this summer of: “How do we cope with cooling homes (as energy efficiently as possible) in a warming global climate?” 2006 set heat records around the world, including in Boulder. While the home was performing adequately with a passive cooling strategy of windows open at night and shut in the morning, it became evident that increasing above-average nighttime temperatures were insufficient for cooling indoor air to a point that the home could maintain comfortable indoor temperatures during the late afternoons and evenings of 95˚-100˚F days. Also, opening and closing windows was increasingly disrupting sleep of family and guests (going into guests’ bedrooms to close east-facing windows and shades at 6 a.m., for example). In response, Eric sought out a cooling strategy that would be as efficient as possible, and would mirror how the house performed in the winter: “[When] the house just hums along, pretty much hands off, and is the most comfortable place we have every lived.”
The solution came in the form of a 220V Coolerado direct/indirect evaporative cooler with ECM motor manufactured in Arvada, Colorado. The variable speed ECM motor means that the blower modulates all the way down to 100 watts of energy usage to circulate 200 cfm of cool, fresh, air – the same amount of circulation at half the energy usage as the ERV – and, the same energy cost as for the Tamarack fan or miscellaneous Vornado fans throughout the home. To ensure that PVs continue to cover these relatively small electric loads, and for the new electric stove and dryer to be installed in August, 2007, Eric will be adding 1.9 kW of PVs to the existing 6.84 kW array in August 2007.
Last year, Solar Harvest came to within 1% of the zero-energy mark on a source energy basis. By eliminating the natural gas demand, increasing PV size, and installing monitoring devices throughout the home, Solar Harvest is expected to exceed the zero-energy mark by a wide margin next year, and the home’s residents will still be living more comfortably than ever before.
Since October 2005, over 2,500 people have toured the home and it was featured in numerous publications, TV and radio programs, including HGTV and Discovery Science Channel (early August 2007). In December 2005, Solar Harvest was rated the most energy efficient home in Colorado, and, in 2006 Eric received many awards including the CRES Sustainable Building Award and Energy Star’s New Millennium Builder of the Year Award.
Eric Doub of Boulder, Colorado has been involved in green building and renovation for over 20 years. His award-winning company, Ecofutures Building Inc., has grown an average of 35% per year for the last 12 years, primarily due to an ongoing dedication to comfort, health, durability and resource efficiency in residential projects.
