The University of Texas at Austin
College of Engineering
IGERT - Indoor Environmental Quality
A Healthy Home is in Your Hands

go green

Go Green!

The term of "green" has become one of the most commonly used terms worldwide, even though its definition tends to vary. In the context of this website, the term "green" will be used to mean "environmentally friendly"1. This section called "Go green" will provide some helpful information on how to promote a healthy indoor environment in your home. Three common terms will be introduced, including:

Green Homes

Built environments dominate total human exposure to many pollutants due to the amount of time that most people spend indoors (about 90% of their time) and the relative levels of indoor and outdoor air pollution. In addition, buildings have huge impacts on the economy and the environment of the ecosystem surrounding since many building activities involve enormous consumption of energy and natural resources. In 2002, buildings accounted for almost 40% of total U.S. energy consumption2. Therefore, there is an increasing interest in green homes. A green home has been defined as "a place that is located and constructed in a sustainable manner to allow its occupants to live, work and play in a sustainable manner"1.

Figure 1: U.S Energy Consumption in 2002Due to growing interest in homes that are better for the environment and occupant health, the U.S. Green Building Council (USGBC) introduced the Leadership in Energy and Environmental Design (LEED), leading to the generation of more environmentally friendly homes that use less energy, water and natural resources, create less waste, and are healthier and more comfortable for the occupants. The LEED in general focuses on eight categories of building design and life cycle performance, including3:

  1. Innovation & design process
  2. Locations & linkages
  3. Sustainable sites
  4. Water efficiency
  5. Energy & atmosphere
  6. Materials & resources
  7. Indoor environmental quality
  8. Awareness & Education


Green Products

Many products contain toxic or irritating substrates that may adversely affect users' health and surrounding environments. For example, interior building materials can emit a significant amount of pollutants, such as VOCs and particles, and therefore can affect the indoor environmental quality4. Thus, "environmentally friendly" or "green" products have become more favorable than before because one benefit is that they emit less of these pollutants5. People are more likely to purchase and/or consume products that are less harmful to the environment6. Some examples of these products include household items that contain recycled material or items that are free of synthetic components. Green products can be defined as products with such characteristics low toxicity, minimal chemical emissions, ability to be recycled, and durability. More specifically, the Whole Building Design Guide compiled a comprehensive list of environmental attributes that a green products have one or more7,8:

  1. Promote good indoor air quality
  2. Durable, and have low maintenance requirements
  3. Incorporate recycled content
  4. Salvaged from existing or demolished buildings for reuse
  5. Made using natural and/or renewable resources
  6. Have low "embodied energy"
  7. No chlorofluorocarbons or other ozone depleting substances
  8. No highly toxic compounds, and their production does not result in highly toxic by-products
  9. Obtained from local resources and manufacturers
  10. For wood or bio-based products, they employ "Sustainable Harvesting" practices
  11. Easily reused and recycled
  12. Biodegradable

However, the issue of which products are better from an environmental standpoint is still controversial. It is important to note that many of the criteria used to select green products are subjective, and a product may perform well under one criterion, but poorly under another. Tradeoffs between different criteria are inevitable. Therefore, once a potential product is identified, that product is carefully assessed for its "greenness." To help customers and builders choose actual green products, there are several groups that provide standards and listings of green products and materials that are currently available:


Green Occupants

The increase in the number of low energy designs or green buildings have not resulted in the reduction of energy consumption off these buildings, leading to a common thought that "technology alone cannot and will not save the environment"9. The high performance of green buildings will be only witnessed if occupants show good housekeeping approaches. It has been shown that optimizing environmental performance of green buildings involves the occupants' behaviors and attitudes toward climate change and air pollution9. Environmental education, peer review, access to finance, and the availability of more environmentally friendly ways are effective approaches to changing an occupants' lifestyle9. The U.S. Green Building Council introduces 45 ways in which occupants can improve the "greenness" of their not-so new home, including these 10 simple steps10:

  1. Lint hint: Lower your energy bill by cleaning your clothes dryer's lint trap before every load to improve air circulation.
  2. Good day sunshine: On cold sunny days, open window coverings to let the sun warm your home. On hot days, close window coverings on the south and west sides to keep your home cooler.
  3. Nix the night-lights: Install motion sensors, photocell controls or timers so outdoor lights are only on when needed. Reduce light pollution and keep the night sky darker by using light fixtures that direct light downward instead of toward the sky
  4. Washing day: washing and rinsing clothes in cold water. You can also save more than 3,400 gallons of water per year, according to Energy Star, by washing full loads instead of partial loads.
  5. Rock-a-bye computer: Enabling your computer and monitor's power management features so they go into sleep mode when idle. Also, turn off computers and peripherals at night.
  6. Prevent energy-wasting air leaks: To stop drafts, install weathers tripping around doors and caulk cracks around windows. Check the heating and cooling systems' ducts to make sure all joints are connected and well sealed. Use a mastic sealant or foil-backed tape to seal ducts.
  7. Automate it: Reduce energy bills by as much as $150 a year with a programmable thermostat that adjusts the temperature when you leave the house or go to sleep.
  8. Blow off some heat: Solar-powered attic fans exhaust hot air and help keep your home comfortable while reducing cooling costs. An added benefit: No need for electrical wiring, so installation is straightforward.
  9. Wrap it up: In the winter, room air conditioners installed in windows can be a source of cold drafts. Remove window units during cold months or insulate them with tight-fitting A/C covers, available from most local home-improvement stores.
  10. Double up: To keep heat inside during winter and outside in the summer, choose double-pane windows with an appropriate low-e coating. For help choosing the right window for your climate, go to efficientwindows.org


External Links

Leadership of Energy and Environmental Design - http://www.usgbc.org/DisplayPage.aspx?CategoryID=19

BRE Environmental Assessment Method: http://www.breeam.org

EnerGuide for Houses: http://oee.nrcan.gc.ca/residential/energuide-for-houses.cfm

Nation-wide House Energy Rating: http://www.nathers.gov.au

Green Building Council - Australia: http://www.gbca.org.au


References:

  1. Ross Spiegel and Dru Meadows (1999) Green Building Materials: A Guide to Product Selection and Specification.
  2. Buildings and the Environment: A Statistical Summary - EPA http://www.epa.gov/greenbuilding/pubs/gbstats.pdf, accessed April 2008.
  3. LEED for homes rating systems - USGBC http://www.usgbc.org/ShowFile.aspx?DocumentID=3638, accessed April 2008.
  4. U.S. EPA - Indoor air pollution: an introduction for health professional. Washington DC 1994.
  5. Consumer Demand for Green Products Increases - Greenguard http://www.greenguard.org/Default.aspx?tabid=43&ItemID=443, accessed April 2008.
  6. Mainieri, T., Barnett, E., Trisha, R., Oskamp, S., & Unipan, J. (1997). Green buying: The influence of environmental concern on consumer behavior. Journal of Social Psychology, 137(2), 189-205.
  7. Prachi Nimse, Abhilash Vijayan, Ashok Kumar , Charanya Varadarajan. A review of green product databases. Department of Civil Engineering, University of Toledo, Toledo, OH 43606. Environmental Progress. Volume 26, issue 2, Pages 131 - 137
  8. Whole building design guide http://www.wbdg.org/resources/greenproducts.php, accessed April 2008.
  9. Stephen Browne and Ian Frame. 1999. Green buildings need Green Occupants. Eco-Management and Auditing, 6(2), 80-85.
  10. 45 ways to green their not-so new house - USGBC http://www.greenhomeguide.org/documents/45-ways-to-green-the-not-so-new-house.pdf, accessed April 2008.

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