www.energystarhomesamerica.com

Issue 11 Volume 3

November 2005

Giving Thanks to Our Builders
from Kelly & Dana Parker
Once again, the holidays are upon us. Thanks to you guys, Guaranteed Watt Saver has made it through another year of thousands of inspections and performance tests. It is at this time we are able to look back and be proud of our collaborations and another successful year. We couldn’t have done it without you. Due to this success, we have been able to expand our services even further, especially our green building services. This year, GWSSI was chosen to serve as one of eleven national LEED for Homes Pilot Program Providers. The program has been in development for several years and we have been fortunate to assist in the first full-scale demonstration. This opportunity has been an excellent learning experience and through it we have become ever more optimistic about improving the quality of homebuilding on an industry-wide scale. All of this is made possible by the clients we serve who continue to look for ways to raise the bar and improve the performance of their homes and deliver an outstanding product to their homebuyers.

It is a privilege to work with builders who understand the value of energy efficient and research-based building practices.. Our work is made easier by the individuals and companies who continue to push the envelope and incorporate new technology and high performance products into their homes.

2005 was an exciting year, and Guaranteed Watt Saver was honored for the third time as an ENERGY STAR Partner of the Year, for our work with innovative builders and our commitment to high performance homes. We also enjoyed the distinct pleasure of working with W.E. Gilbert Co. in unveiling Houston’s new green building program, the GreenBuild Initiative. To learn more about the program, please visit www.gwssi.com/buildgreen It is our hope these achievements will only lead to more successful collaborations in the future and greater prosperity for all.

As we look forward, we are encouraged by the gaining momentum for energy efficient and green building practices and feel that next year will be even better.  We are commited to fostering strong relationships and friendships with our clients and partners and will work to continue providing the highest quality services. Thank you for allowing us to be a part of your team and we wish you great success in the year to come!
Inspector’s Corner
The Elements of a Comfortable Environment
by Kenneth Lackey, DFW Supervisor
     Heat gain is unwanted heat that accumulates indoors causing discomfort (see fig. 2-1). Less than 10 percent of the heat that accumulates in a home is driven through the walls and roof by high outdoor temperatures. Solar gains, air leakage, and internal gains comprise the remaining 90 percent. Solar gains through the windows, roof and walls are the greatest source of unwanted heat - 50 percent or more of the total heat gain. Internal heat gains are generated inside the home by people, lighting, and appliances. Air leakage is outside air that leaks into a home, and indoor air that leaks out. Table 2-A shows the type of heat gains as a percent of the total heat gains. *Note that air leakage and internal gains provide both humidity and heat. Reducing Heat Gains:

     Internal gains come from indoor activity. Internal gains are divided into two categories: internal heat and internal humidity. The primary sources of internal heat are lighting and appliances. The refrigerator and the water heater are major heat sources: the washer, dryer and stove each add heat and humidity.

     If possible, you should isolate the water heater, washer and dryer from the cooled living space to prevent them from heating and humidifying your home (see fig. 2-3). Seal all air leaks between the living areas and the utility areas where they are located. (remember that the dryer needs a supply of air, and gas appliances need a source of combustion air from outdoors.)

     Reduce heat and humidity during hot weather by washing clothes in cold water, drying clothes outdoors, using the microwave instead of the oven (when appropriate) and barbecuing outdoors.

     Fluorescent lighting provides the same light levels as standard home lamps for about 25 percent of the energy cost and heat production. Compact fluorescent bulbs screw into a standard light socket and save money on both lighting and cooling. The new light bulbs are appropriate for fixtures that are used at least 3 hours a day.

     Efficient lights and appliances are worth the extra initial cost (which may be substantial). They are less expensive to operate, and they release less unwanted heat indoors.

Reducing Air Leakage:

   Normal air leakage doubles when a central air conditioning unit is turned on. This is caused by pressure and suction created in the air conditioner and ductwork. Joints in ductwork are often the most important sources of air leaks in a home.

   Windows and doors are not the major source of air leakage in most homes. Large hidden leaks generally account for far more air leakage than doors and windows. Areas such as ducts, plumbing penetrations, exhaust fans, electrical service boxes, fireplaces, and chimneys are usually the main culprits. Fig. 2-3 shows where to look for air leaks in your home.    Heat gains from air leaks are more expensive in humid climates than drier climates. An air conditioner must remove humidity from the air to provide comfort, and this drying process takes a lot of energy. Air leakage accounts for 10 to 30 percent of the cooling load, depending on the size and number of the leaks and the relative humidity of the air entering the home.

   Blower door testing is a practical and effective technique for measuring and locating air leakage in homes. Blower door testing determines the total amount of air leakage within the home.  If you decide to seal air leaks, the blower door locates specific areas in the home that require sealing. Blower door testing is the only really accurate way to determine whether or not you need to seal air leaks.

Reducing Solar Gains:

   Heat from the sun shining through windows and on building surfaces (called solar gains) is the major source of unwanted heat. The most effective way to reduce solar heat gain is to stop the sun’s rays before they enter the building by reflecting the rays or blocking them with shading devices. Reflectivity is the ability of shiny materials or light colored materials to reflect solar heat away from the home. Shading means putting a solid object between the sun and parts of the building, to absorb or reflect the solar heat. Shade trees, vines on trellises, sun screens and awnings provide effective shading to windows by reflecting solar heat or absorbing the heat outside the home. Shades, draperies, and blinds can be effective shade givers too, but they must be closed, blocking daylight and the view through the windows.

Announcements:
Last month we received a question from a subscriber and this month, Kelly Parker provided a response:

Question:
   “I am considering building another home for myself in the very near future. I would like your opinion on A/C systems and what the best set up is for allergies, dust control, comfort and fresh air. The home I build will be tight and will need fresh air. The last time I built I used an ERV, Humidistat, Media filters w/UV, 14 SEER Amana dual speed system with return airs in all bedrooms as well as main part of home. Let me know your thought. I want to build an energy conservative and healthy home as best I can without breaking the bank this time.”

Kelly’s Response:

• I would begin by sizing my house appropriately to the size of the family.  There are numerous criteria for this. LEED-H (for Homes) has tackled the issue and set forth reasonable and prudent guidelines.  The first thing to do is be content with an adequately sized home because in the future, energy will not be plentiful. The oversized McMansions built today could be tomorrow’s apartment buildings.   
• The best way to answer this question is to examine all of the individual components of high-performance homes. Generally, I will limit this examination to mainstream building practices and not custom, high-efficiency, cutting edge technologies. We are talking about standard, stick-built framing.
• Envelope/Enclosure – Enclosure of the home is the assembly which in the most basic sense separates the inside from the outside. Conditioned air should remain separate from unconditioned air, no matter where the home is built - anywhere in the U.S. I would build the enclosure with as much exterior insulated sheeting as I could readily afford in the construction process without drastically affecting the siding/brick, etc. One inch of insulated foam, extruded polystyrene, is widely available and  comes in many colors, blue, green, etc. Two inches is even better.
• Wall Insulation - Depending upon how thick I choose the exterior envelope insulation, I may or may not want to insulate the interior cavity. If I could get away with 4”- 5” exterior insulation in most climates - I would not insulate the wall cavity. But assuming I insulate the wall cavity, I would then go with a good system of blown insulation. There are benefits to both blown-in cellulose and blown-in fiberglass insulation.  Local prices or availability may be a determining factor.
• Attic Insulation – use a blown-in cellulose product. The benefits of blown-in cellulose in an attic situation outweigh the benefits of blown-in fiberglass.  Fiberglass insulation is continually increasing in price more so than cellulose insulation. The cellulose insulation is a recycled and treated product.  In some climates I have seen pesticides sprinkled over the fiberglass insulation and I think this is a mistake. I would rather use a product with inherent properties for inhibiting pests such as cellulose.  In most markets, the cellulose is going to be a less expensive product. 
• HVAC - The Heating, Ventilation, and Air Conditioning component of a house.  If I were building in a southern or a northern climate, I would install a minimum of a 90% gas furnace. A good system would be a 90% gas furnace, a better system would be a dual fuel with a 90% gas furnace, and the best system would be a geo-thermal system, which may not be applicable in all climates, depending on soil conductivity.  The efficiency of the AC system should be a minimum of 14 SEER, and the ventilation component in southern climates should be a stand alone dehumidification system with a 6 inch fresh air intake. In northern climates, for ventilation I would install a heat recovery ventilator.  The stand alone dehumidification system is better than an ERV in southern climates.  Basically the cost is about the same for both, but with the dehumidification unit you are getting separate dehumidification.  One issue that needs to be brought up at this point is that manufacturers of heating and cooling equipment are continually coming up with dehumidification cycles on the equipment. Although this is a wonderful one- piece unit, if you evaluate the cost of operation you will find the dehumidification component on the central system costs more per month to operate. Therefore I believe a stand-alone unit with a 14 SEER or better is the best choice.  I would also confirm that all bathrooms and kitchen exhausts vents vent to the outside with a low sone (sound rating) unit.   
• Now back to the enclosure – During the building process of the exterior enclosure, I would make sure to create a proper rain plane and properly flash all fenestrations with flashing tape and housewrap. The exterior of the enclosure should be a more durable product, such as rock or stone. 
• At the bottom of enclosure you would want to choose foundation depending on the climate and make sure the floor and foundation are properly insulated. If using a slab on-grade, in which wood floors are used, I would specify ¾” or greater aggregate stone underneath the foundation and the concrete floor slab. This will eliminate the migration of moisture up into the floor slab, which is the leading cause of wood floor failure.                 

Enclosed is a downloadable diagram (pictured above) that can be accessed from our website which will help detail building systems that work. http://gwssi.com/Resouces/BuildingSpecs/insulation/insulationsystemsmodel.pdf
Obviously in this short article I have not had time to explore any further in depth in a few short sentences.  Remember, if you build a house that is adequate for your needs and build each component as if resources and energy were not infinite, then you would begin to see a restoration of our nation’s resources.

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