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EarthCraft Virginia e-newsletter
Sensibly Built for the Environment! Issue #2, July 2009 |
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Upcoming Trainings July 22, 2009: August 24, 2009: September 23, 2009: September 30, 2009: To register, please visit our website, www.earthcraftvirginia.org, and click on the “trainings” menu item. There you’ll find the registration forms. Remember, you must be registered in advance! |
From the Executive Director
According to Mrs. Chmura, we should expect, “GDP to contract 3.1% in 2009 before growing 1.1% in 2010. The recovery is expected to take hold in the first quarter of 2010 as (1) the banking industry continues to improve, (2) the inventory overhang of houses, retail, and manufactured goods is reduced, and (3) the stimulus from the Federal Reserve and federal government continues to impact the economy. Contractions in residential and nonresidential investment are expected to weigh heavily on the economy in 2009 with housing activity finally picking up in the first quarter of 2010.” As the residential housing market regains its stability it is essential that we understand the clients’ wants and needs. The truth is that the consumer is more aware and educated on green building than ever before. Those that have been waiting to buy a new home will be attuned to energy efficiency, water conservation, comfort, durability, indoor air quality, and materials and finishes that are more environmentally friendly. Industry leaders have taken notice and recognize that green building is not a trend but rather an expectation. Despite the housing market downturn builders have been actively participating in EarthCraft House trainings and preparing to clearly communicate their message. Green building is here to stay and I commend you all for taking the initiative to reach a higher standard. Sincerely,
Stix & Brix Typically, heat pumps and air conditioners achieve optimum efficiency when systems run continuously. Therefore it is important that these systems be sized to achieve the longest run times possible. Standard sizing calculations are based on a design temperature that is exceeded on 73 hours in a normal cooling season. (ASHRAE standard 2.5% design--Outside summer temperatures and coincident air moisture content that will be exceeded only 2.5% of the hours from June to September. In other words, 2.5% design conditions are outdoor temperatures historically exceeded 73 out of the 2,928 hours in these summer months). An air conditioner sized to run continuously at design conditions will cost less initially, will have a longer life and a lower operating cost. While it is possible with air conditioning to ensure that the temperature at the thermostat can be as cold as we set it, being cold alone is not comfortable. In fact, it is distinctly uncomfortable. To maintain a general level of comfort, the moisture level must also be controlled. In order to design indoor environmental conditions that make people comfortable, ASHRAE conducted studies to determine how people feel under varying temperature and humidity conditions. The result of this research was the identification of a “comfort zone” based on temperature and humidity. Tolerance to heat is affected by the amount of humidity in the air--at higher temperatures, the humidity level must be held lower to ensure comfort.
The ability of the air conditioner to remove moisture (latent capacity) is lowest at the beginning of the air conditioner cycle. The moisture removed from the indoor air is dependent upon the indoor coil temperature being below the dew-point temperature of the air. The moistures then wets the indoor coil and, should the unit run long enough, will begin to flow off the coil and be removed out of the condensate drain. For short cycles, the coil does not have time to operate at the low temperature and when the unit stops, the moisture on the coil evaporates back into the indoor air. Thus, in mixed humid climates like Virginia, a properly sized air conditioner will do a far better job of removing moisture from the air than oversized units which would not remove enough moisture to prevent it from being cold and clammy. The ASHRAE cooling design temperature for Richmond, Virginia (based on a thirty year average) is 91°F. At this design temperature a properly sized air conditioner should run 100% of the time and should maintain indoor environmental condition within the range of the “Comfort Zone”. Occasionally there may be periods when outdoor conditions exceed the design criteria and properly sized systems may have problems maintaining set-point temperatures. However, this would not warrant increasing sizing because it would create problems associated with short cycling, i.e., high relative humidity levels, poor indoor air quality, high operating costs, and decreased system life. Showcase Single Family Builder Luke Construction incorporates whole system approach to achieve EarthCraft Gold Certification David Luke recently completed his third EarthCraft House and his second certified EarthCraft Gold™ home. The home, located off of Carolina Avenue in Virginia Beach, earned a HERS index of 35--one of the lowest ratings EarthCraft Virginia has seen to date. This design/build led to a home that consumes 65% less energy compared the same house built to the IECC 2004. Some of the energy efficient features that led to such a high performance building include:
Homeowners Jim and Debbie Flanagan are thrilled with their new home. This is the 2nd EarthCraft Home that Luke Construction has built for them and they plan to use David in the near future. Jim and Debbie add, “An EarthCraft House is one of the most high-performance, durable and resource-efficient homes you can buy… We will be using Luke Construction again this fall for our next project.”
Jim and Debbie Flanagan’s EarthCraft Gold™ ICF home built by Luke Construction. The home earned an HERS index: 35 Multifamily Project: The Windy Hill Foundation and TM Associates’ Levis Hill House was certified under the EarthCraft Multifamily New Construction Program was recently recognized by the U.S. Environmental Protection Agency and US Department of Housing and Urban Development. The Windy Hill Foundation received the Regional Energy Star Award for Excellence in Energy-Efficient Affordable Housing for the 20 unit Elderly Housing project located in Middleburg, Virginia. Notable features of the project include:
Aside from the recent award from Energy Star, Levis Hill House – Loudoun County’s first certified green apartment building – has also received recognition from the National Council of Affordable and Rural Housing. Though the awards for the project team are nice, with energy bills for one-bedroom units anticipated not to exceed $35 per month, the real winners are the residents that call Levis Hill House home.
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Features & Dedications Rutledge Hills Apartments - Amherst Goodson House – A living Green Demonstration House - Newport News Hurt Park Townhomes - Roanoke Wesleyan Place - Virginia Beach |
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Habitat for Humanity Greater Charlottesville HFH Charlottesville Habitat has been building EarthCraft houses for over two years, with 10 projects certified and at least 6 more now under construction. Electric bills from Charlottesville Habitat homeowners have been extensively analyzed by University of Virginia students, who are finding that these EarthCraft certified houses tend to use 25-30% less energy than the more traditional Habitat homes. Energy efficiency is important for any affordable project, so these houses each feature a small efficient heat pump and mastic sealed ductwork located entirely within conditioned space. Charlottesville Habitat has also been dedicated to pursuing a much wider range of green features. A continuous layer of blue board insulation (1/2” extruded polystyrene) wraps the houses to reduce any thermal bridging effect through solid framing and increase the R-value of the exterior walls. Blue board scraps are also used to add insulation in window and door headers, cap duct chases, and fill any gaps that require air sealing. Sprayed cellulose insulation (recycled newspaper), open cell sprayed foam, and volunteer-installed cotton batts (recycled blue jean material) have each been used on a number of houses. All of the houses have included a standing seam galvalume metal roof. This reflective roof surface decreases the amount of heat transferred into the building, is very long lasting, and all the waste scraps can be recycled. Precast insulated foundation wall panels form the conditioned crawlspaces or basements, which requires much less concrete than a solid wall on a poured footing. Rain chains leading to cisterns stored under the porch have been used to collect water for lawns and gardens. Fiber cement siding and borate treated lumber are used on the exteriors. Low VOC paints, caulks, and adhesives are used on the interior because the building envelopes often test tight enough to require additional ventilation, which will help maintain a much more healthy and comfortable indoor environment. Charlottesville Habitat has been continuously developing their green building strategies over several years of working with EarthCraft Virginia, and we are looking forward to their upcoming projects.
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The EarthCraft Virginia program is made possible by the support the support of its sponsors and partners. These organizations help fund the promotion and administration of the program. If you are interested in becoming a sponsor, or would like more information on the different benefit packages, please contact us at (804) 225-9843 or admin@earthcraftvirginia.org. |
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EarthCraft Virginia * 1431 W. Main St. * Richmond, VA 23220 * 804.225.9843 * www.earthcraftvirginia.org |
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