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EarthCraft
Virginia e-newsletter Sensibly
Built for the Environment!
Issue #2, July
2009 | |
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 Recently, Mike
Toalson, Vice President of the Home Builders Association suggested we join
HBAV for their annual convention, held in Hilton Head. Between
tennis tournaments, golf tournaments and terrific meals, we were able to
share EarthCraft Virginia’s accomplishments during one of the learning
sessions and reunite with some of our EarthCraft House Builder
members. We also heard from Christine Chmura, President and Chief
Economist of Chmura Economics & Analytics, as she walked us through
the elements leading us into this recession, and hopefully out of it.
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 comfort
zone was found to be acceptable to 90% of test subjects drawn from a range
of age groups and genders, with work and life-styles involving varying
levels of activity and clothing. An air conditioning system that
establishes and maintains indoor conditions within this zone will provide
thermal comfort for 90% of the population. It will produce a neutral
sensation--occupants will feel neither too hot nor too
cold. 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:
·
ductwork - the
ICF house allows for all HVAC equipment and ductwork to be located in
conditioned space, contributing to mechanical systems that perform at
higher efficiencies as well as reduce duct leakage outside building
envelope (less than 4% duct leakage outside the building envelop).
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. |
Features &
Dedications Rutledge Hills
Apartments - Amherst Goodson House
– A living Green Demonstration House - Newport News Hurt Park
Townhomes - Roanoke Wesleyan Place
- Virginia
Beach | |
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. | |
The EarthCraft
Virginia program is made possible by the support of its sponsors and
partners. If you are interested in becoming a sponsor, please
contact us at (804) 225-9843 or [email protected].
| |
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[email protected]. | |
EarthCraft
Virginia * 1431 W. Main St. * Richmond, VA 23220 * 804.225.9843 * www.earthcraftvirginia.org |