QUESTION: I want to build a super-energy-efficient house using building products that are made from recycled materials or are made by energy-efficient methods. What specific types of building products should I use?
ANSWER: If you shop carefully, you should be able to find recycled or low-energy-intensive building products to meet most your material needs. Many of these energy-efficient products use more than 50% recycled materials and require little additional energy for processing.
These new "earth-friendly" building products include structural framing, foundations, walls, roofs, sheathing, insulation, interior wall and floor coverings.
For exterior wall or roof framing, chose products that use as little lumber from old-growth trees as possible.
Instead of using 2x10 floor joists, you can use "I-joists," which require less wood for the same strength. Also glue-laminated lumber and laminated veneer lumber use smaller pieces from second-growth trees to make large defect-free lumber.
To even further reduce the amount of lumber, use super-insulated stress skin wall panels. These use only 5% wood as compared to 20% wood in a conventional studded wall.
Another new wall panel uses a super-strong and efficient honeycomb structure made from recycled resin-impregnated paper.
Producing cement for foundations and slabs is very energy intensive. ACC (autoclaved cellular concrete) uses small amounts of aluminum in the concrete. This creates small bubbles causing the concrete to expand and become less dense as it cures. It is still very strong, but requires less cement. Waste fly ash from power plants can replace about 20% of the cement.
Many organic asphalt shingles contain recycled mixed waste paper. Some of the residential aluminum "shake-looking" roofing is made from 100% recycled beverage cans. Metal roofing also can cut your cooling costs. If you like the look of wood shakes, select ones made from remanufactured wood fibers.
Many types of insulation are made from recycled and fireproof treated newsprint or waste mineral slag. One type of blowing wool fiber insulation is made from 100% recycled telephone books. Rigid insulating foam wall sheathing is now made from recycled foam containers.
You can use gypsum-like wallboard made from waste ryegrass straw. Another type is made from waste paper and rice hulls or peanut shells. Some resilient tile flooring is made from recycled car tires. One company makes solar ceramic tiles from recycled waste glass from a light bulb factory. Some attractive carpeting is made from recycled plastic bottles.
You can write for Utility Bills Update No. 355 listing addresses and telephone numbers of 70 manufacturers of "earth-friendly" building and home improvement products and descriptions of their products. Please include $1.50 and a self-addressed business-size envelope. Send to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.
Using Heat Escaping From Clothes Dryer
Q: During the winter, I moved my electric clothes dryer far from the window vent. This should have allowed some heat to transfer to the utility room before it blows outdoors. Was this a good idea?
A: In theory your idea is a good one. However, there are some potential problems. First check with your dryer manufacturer about the maximum duct length. A very long duct can cause excessive back pressure.
Another potential problem is a fire from accumulated lint. For a long duct, over 20 feet, always use an aluminum duct, not plastic.
\o7 Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.