www.energystarhomesamerica.com

Issue 3  Volume 3

March  2005

ENERGY STAR 2006
Changing Guidelines...We’re Here to Help!
By Samantha Pearson

“Significant changes are happening in the world of energy efficient construction.” This is the opening line from the PROPOSED changes to the Guidelines for ENERGY STAR Qualified Homes for 2006. We are aware that these proposed changes will affect our builders and would like to keep you as informed as possible. These are proposed changes and while the framework may change as a result of stakeholder feedback, the overall specifications are a good indication of what is to come. 

The most significant change will probably be the national minimum standard for air conditioner efficiency. 
Here are a few of the PROPOSED guidelines:

• The new HVAC minimum will be 14 SEER. 
• Maximum duct leakage will be 4 cfm per 100 sq.ft. which approximates 6-7% outside leakage. 
• Home envelope leakage will remain at 0.35 air changes per hour or less. 
• Water heater efficiency minimum will be at 0.60 Energy Factor for gas systems and 0.92 Energy Factor for electric systems. 
• It is also proposed that 5 or more ENERGY STAR qualified lighting fixtures be integrated into the home.  These can be comprised of ceiling fans and appliances.   A specific list of acceptable fixtures will be provided in the final draft.

The final draft of the Revisions to the Guidelines will be issued in June 2005.  We can assist you in converting your homes to the new standards at this time.  We can run comparisons and inform you of your current standings and how these changes will affect you. You are welcome to implement the new program guidelines in June of this year but it will not be required until January 2006. 

We are here to assist you in making this transition as seamless as possible. If you have any questions, give us a call!

Inspector’s Corner
By: Derrence Freeman - City Manager, Houston

Exhaust Fan Ventilation

There are several important factors to consider when introducing exhaust fan ventilation into a building. The purpose, operation, duct installation, termination of duct runs and testing procedures is the primary focus of this article. The main purpose of an exhaust fan is to remove moisture and residual heat. Exhaust fans are usually located in areas where there is greater moisture content such as lavatories, bathrooms, kitchens, and laundry rooms. In kitchens, cooking and boiling water produce a lot of moisture; the dishwasher and sink can also produce a lot of moisture. The same holds true in the bathroom; an average shower lasts 12 to 15 minutes according to US statistics. Many showerheads put out 7.3 to 8.2 gallons of water per minute. A hot shower somewhere around 90 degrees Fahrenheit creates a lot of moisture in the bathroom. It is recommended by building science professionals to let the exhaust fans run 15 to 20 minutes after every use to allow the moisture content to be removed. In the laundry room you have a washer and dryer where there is hot water use. Even with cold water there is some moisture that will be contained in the air. Most of the moisture comes from the residual heat in the dryer that is steaming the clothes inside the dryer compartment. This steam is supposed to be exhausted out of the vent pipe to the outdoors, but there is a residual amount that is contained inside the room. If you put a moisture meter inside a laundry room, bathroom or kitchen while there is activity, you will find that moisture levels increase by 20%. So, understanding that moisture removal is the key point to the exhaust fan, the exhaust helps in maintaining indoor air quality. The summertime relative humidity that is most comfortable for the average person in this country is between 30% and 60%. Most homes that are energy efficient will have a relative humidity in the low 50% range. When the home’s relative humidity is high it can also trap odors and cause greater moisture containment within the home. Indoor air quality is the number one problem to most people living in homes where there is not enough ventilation, too much moisture or the trapping of stale air.

The next important factor dealing with exhaust fans is duct installation and sealing. For bathroom fans, use ducts with a diameter at least 4” and longer runs use 6”. Aluminum duct tape or mastic is the best product recommended to seal the duct and reduce possible air and moisture leakage. Most exhaust fans have gravity dampers that close when the unit is off and opens when it is on. It is understood by building science professionals that for every 90 degree turn a duct run makes you can loose 10%-15% of the rated fan flow. This leads us to the termination point of the duct run. Most of the time we find duct runs are terminated in the attic, where the moisture is dumped and settles onto the insulation decreasing its R-value and increasing the potential for biocontaminant growth. Some ducts are terminated in the soffit, this is not a bad idea but the soffit is designed to allow air to come into the attic so the stack effect (buoyancy of warm air rising) can draw air in and the warmer air can lift out of the roof vents. It is understood that the best termination point is through the roof jack. Local codes must be followed along these lines.

It all comes down to inspecting and testing for proper flow. An exhaust fan flow meter measures for rated flow. Guaranteed Watt Saver performs visual inspections to ensure the duct is sealed and installed properly. Another concern that consumers have about exhaust fans is noise level, which is measured in sones. The higher rated the cfm flow, the noisier the fan, but manufacturers are now creating higher capacity fans with lower sones. If there are any questions about exhaust ventilation log on to www.gwssi.com or call 1-888-488-0206.

Announcements...

Attention Builders:
Oklahoma City will host the next EEBA Houses That Work Educational Series on Friday, April 15 from 8:00 am -4:00 pm. This year’s speaker is Mark Laliberte, an EEBA certified trainer.

In this session you will learn about:
- Design concepts for advanced framing, moisture management, HVAC, Insulation, IAQ, & ventilation control
- Constructing a better performing building envelope
- How to reduce costly callbacks and warranty problems
- Re-engineering strategies for maximum efficiency
- The latest technologies in the marketplace
- Proven marketing techniques
- Real-life success stories and case studies

In addition to the wealth of information provided, you will also receive lunch and refreshments, reference materials and product demonstrations. You may also earn Continuing Education Units.  The session will be held at Central Oklahoma HBA, Inc. at 625 N.W. Grand Blvd. Oklahoma City, OK.
For more info, contact Julie Porter at 952-881-1098 or vist www.eeba.org.

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