www.energystarhomesamerica.com

Issue 5, Volume 2

May 25, 2004

The First “Zero Energy” Home in North Texas
by Tina Evans, Marketing Coordinator

Barley+Pfeifer Architects and Anderson Sargent Custom Builder LP have teamed up to participate in the US Department of Energy’s “Zero Energy” Home (ZEH) building program. This program is designed to encourage homeowners and builders to live and build in a more fiscally and environmentally sensible manner. This partnership will produce a home that demonstrates you can live in a more environmentally responsible manner while enjoying greater comfort than most new homes offer today.

GWSSI is working with Jim Sargent and Building Science Consortion to evaluate the home and provide a HERS rating. GWSSI/Building Science performed the analysis on the home and produced the rating which resulted in a HERS score of 94.5 and was 49.7% above the IECC. This home is one of the most efficient homes GWSSI has rated in the state of Texas.

A ZEH is a home that produces all the energy it uses on an annual basis. The north Texas, 3800 square feet, four-bedroom home will be completed in August. The actual utility costs are roughly equivalent to homes 1/3 the size, averaging less than $70 a month for electricity and gas. Once the benefits of the solar photovoltaic panes are factored in, the net cost to operate this house should be zero. Proper solar orientation, a ventilated radiant barrier roof system, careful air-infiltration control, spray foam insulation, DURISOL block construction, air sealed attics, accurately sized roof overhangs, a light exterior color scheme, enhanced natural ventilation, and permanent metal air-conditioning ducts are among the technical strategies included that make this home perform so well. With the reduced energy needs and solar energy systems, a ZEH can return as much energy at it takes annually from the utility grid.

Zero Energy Homes have four main advantages:

• Improved comfort – reduces temperature fluctuations
• Reliability – function during blackouts
• Security – protects owner from fluctuations in energy prices
• Environmental sustainability – saves energy and reduces pollution

This ZEH is the featured home in the 2004 Dallas Parade of Homes in September. It is predicted that over 40,000 people will tour the home during September 4 through September 26. In addition, seminars will be held in the home during EEBA/Sunbelt Builders Show October 20-23. Trade events for builders, remodelers, and architects will be held September 18 through October 25. For more information about this Zero Energy Home contact Jim Sargent at (972) 617-3788. GWSSI plans to cover the progress of the Zero Energy Home in upcoming newsletters so stay tuned for more information on this exciting project.

GWSSI Adopts the Home Energy Rating Disclosure Form
By: Maci McDaniel, National Marketing Director

As we told you in our December issue, the Home Energy Rating Standard Disclosure Form has been approved and adopted by RESNET, however, the form is not required to be used by raters until January 2005. GWSSI believes this form is a vital tool for communicating a rater’s potential conflict of interest to builders, municipalities, lenders and home buyers. As such, GWSSI has adopted the use of this form as a best practice and has already started to provide the new Disclosure Form with every rating. 

GWSSI is committed to being a leader in the industry by providing third party ratings, inspection and performance testing services to our clients. To further our efforts to be such a leader, we believe that early adoption of this practice will help educate the industry and provide vital information to interested parties on the value of third party certification and inspections.

For more information on the Home Energy Rating Standard Disclosure Form, please contact a GWSSI Market Manager or view it on RESNET’s website.

Inspector’s Corner

IAQ Problems - What causes them and what to do about it
by Kenneth Lackey, Dallas/Ft. Worth Supervisor

Indoor Air Quality (IAQ) has recently become a concern because of the improved building standards. This has resulted in increased insulation and reduced energy-consuming ventilation systems. The combination of these factors has led to an increase in indoor air quality complaints. See Figure A.

The majority of IAQ concerns stem from poor ventilation, poor filtration, and contaminated HVAC systems.

Indoor Air Contaminants
There are two major indoor air contaminants: bioaerosols and carbon dioxide.

Bioaerosols are airborne microorganisms derived from viruses, bacteria, fungi, protozoa, mites and pollen. They are found both indoor and outdoor. Excessive indoor moisture increases the growth of some microorganisms. Certain types of humidifiers, water spray systems, and wet porous surfaces act as breeding grounds. Microorganisms in the indoor environment may cause allergic building related illness (BRI).

Inadequate prevention system maintenance may provide nutrients for growth of bacteria such as Legionella. The design of the equipment and proper maintenance of the system may reduce risk. The HVAC system should be checked whenever medical evidence indicates the presence of diseases (such as humidifier fever, allergic asthma and allergic rhinitis, etc.).

Carbon Dioxide (CO₂) is inhaled and exhaled by humans. The concentration of CO₂ in exhaled breath is fairly constant, approximately 3.8%. Once the CO₂ leaves the mouth, it mixes with the surrounding air. When people exhale CO₂, they also exhale other gases, odors, bacteria, and viruses. When these build up in a space due to poor ventilation, poor air quality results. When this occurs, occupants often complain of fatigue, headaches, and general discomfort. Carbon dioxide does not create these symptoms. However, high CO₂ concentrations indicate that these other contaminants may also be present.

Diagnosing Indoor Air Contamination
A procedure for diagnosis and lessening of indoor air contamination is shown in Figure. B. When evaluating the ventilation, ASHRAE Standard 62-1989 should be used.

1. Obtain a description of symptoms from the occupants. Some of the areas of concern are physical symptoms, odors, and the frequency and time of their occurrence.
2. Determine the possible sources. Examine the ventilation system and carefully review potential sources of contaminants. If the source is not evident, continue to step three.
3. Take an air pollutant sample and perform a chemical analysis. Sampling should be done at the indoor location and at an outdoor location near the system air inlet. Building-related contaminants usually peak in the morning after the system has been inactive throughout the night. Occupant-related contaminants usually peak in the late afternoon. Following the interpretation of data, proceed to Step Four.
4. The proper procedures are implemented to correct the problem. Possible solution for IAQ problems may include increased ventilation, air cleaning and control of the problem areas. The following corrections should lead to a healthy building:
• Servicing Ventilation Systems
• Measuring Filter Efficiencies
• Duct Cleaning

If you are experiencing Indoor Air Quality problems, contact Guaranteed Watt Saver at 1-888-488-0206

Althouse, A.D., C.H. Turnquist, A.F. Bracciano, Modern Refrigeration and Air Conditioning. Goodheart-Willcox Co.
 

 
Ask the Expert

Do you have a question about building science, energy efficiency or mold? Well, now you can Ask the Expert. E-mail your question to expert@gwssi.com to get an answer. GWSSI will choose one question to answer in next month’s newsletter.

*The expert will be unable to personally reply to all questions due to the high volume he may receive.
 

If this E-mail does not display correctly, click here to view in your web browser

Plain Text Version