Type A chimneys are made up of two stainless steel tubes separated by insulation. This kind of chimney was banned in Saskatchewan for new gas-heated homes in 1986. Non-insulated Type B chimneys are now used for new gas-heated residences, but Type A chimneys remain in place on thousands of homes. In the United States, carbon monoxide causes more than 200 deaths annually and according to a study by the Mayo Clinic, there are up to 10,000 near misses each year. AlumiNews, March 1994, P.O. Box 400, Victoria Station, Westmount, Quebec, Canada, H3Z 2V8 Tel: (514)489-4941; Fax: (514)489-5505.

Utilities Moving Off the Grid. Following the lead of Idaho Power, Niagara Mohawk in New York announced that it will test electric service for "off-the-grid" customers this year by providing hybrid photovoltaic systems. The systems will use a 1-kW PV array to charge a battery storage system capable of providing 100% of a home's power needs for up to four overcast days. As a backup, the systems will include propane-powered generators. The research project will focus on a home in Parisville, New York, located four miles from the nearest utility lines. If successful, Niagara Mohawk may offer the service to as many as 300 customers who live in remote areas and therefore lack reliable and affordable power. Idaho Power was the first utility to offer off-the-grid systems (see "Paying for the Sun?" HE May/June '93, p.16). To date, the company has completed five installations. Idaho Power maintains ownership of the PV systems, and customers pay a flat monthly fee. Customers are assured system reliability through the use of a toll-free phone number. The $5 million program will run for three years and encompass up to 50 systems. Ultimately, the utility hopes to offer the service to hundreds of customers. The Energy Newsbrief, IRT Environment, P.O. Box 10990, Aspen, CO, 81612-9689. Tel: (303)927-3155; Fax: (303)927-9428.

Home-Scale Hydro. Advances in hydroelectric systems have made the technology practical on a small scale, such as powering a single home. A water source may yield only a few quarts of water per second, yet still be able to power a house. One of these advances is the micro-turbine, which generates electricity when its miniature water wheel, connected to a pickup-truck generator, is spun by a stream of pressurized water. It requires only a small water stream to be effective. Furthermore, solid-state inverters, which convert direct current (DC) to alternating current (AC), and load controllers, which regulate the amount of electricity produced, now employ computer chips, allowing them to perform more effectively and energy-efficiently than their predecessors. The high fees that utilities often charge to extend power lines to remote areas make hydro-power particularly economical for homes not connected to the utility grid; those that are connected can also benefit from the technology. A small water source such as a stream or brook can produce 400 watts continuously, which is enough to power a modern house with conventional appliances (that doesn't include space and water heating, cooking, and clothes drying, though; energy for these uses is supplied by other fuels, such as wood or propane). Direct current systems store electricity in batteries, which is then drawn and converted to AC as needed. A 400-watt DC system costs $4,000 to $6,000. AC systems, which generate AC electricity directly, cost about $7,000 to $20,000. Even though they generate much more electricity than DC systems, only one in 10 sites can support an AC system. Mother Earth News, April/May 1994, Sussex Publishers, Inc., 24 E. 23rd Street, New York, NY 10010. Tel: (212)260--7445; Fax: (212)260-7210.

Controlling Moisture in Crawlspaces. An investigation at the Wood Building Research Center at the University of California Forest Products Laboratory concluded that polyethylene ground covers can effectively deter moisture problems in crawlspaces. The study was conducted at a condominium complex near San Francisco. The level site had expansive clay soil, and in some places there was as little as 8 in. between the wood structures and the earth. Rain gutter downspouts emptied against the foundation. The crawlspaces were poorly ventilated (below code requirements) and clothes dryers were vented through leaky ducts running through them. Some of the problems include foul odors, condensation, mold growth, and wood decay. Researchers monitored humidity and moisture in four of the complex's units for two years. After one year, polyethylene ground covers were installed in two of the units. Crawlspaces in the protected buildings showed "much lower" average relative humidity and wood moisture content (16% in covered units, compared to 20 to 25% in uncovered units). Energy Design Update, February 1994, Cutter Information Corp., 37 Broadway, Arlington, MA 02174. Tel: (617)648-8700; Fax: (617)648-8707.

Redesigning Fluorescents. A too-high temperature inside fluorescent lighting fixtures often results in these systems producing less light and consuming more energy than they should. Higher temperatures can also cause a color shift to blue-green, reducing color rendering and lamp life. But researchers at Lawrence Berkeley Laboratory, in Berkeley, California, have developed several technologies to help manufacturers overcome these problems. Their solutions include modifying lamps and fixtures to achieve conductive and convective cooling, respectively, and using mercury amalgams. A technology for tube fluorescents, called a "spot cooler," can increase light output by 15% and efficiency by 8%. A copper strip installed around the tubulation in compact fluorescents whose bases point down helps conduct heat away, allowing the lamps to operate at 99% of rated light output. Another strategy is to redesign fixtures for passive cooling. Ventilation slots, for example, were shown to improve the light output of recessed CFLs by about 20%. The research also revealed that simply tilting the lamp downward will improve air circulation. The LBL strategies are reported to add very little to manufacturing costs. Center for Building Science News, Winter 1993, Mail Stop 90-3058, Lawrence Berkeley Laboratory, University of California, Berkeley, CA 94720. Tel: (510)486-4508; Fax: (510)486-5394.

Building with Resource Efficiency. "Resource efficiency" is becoming a popular term these days. But what does it mean and how does one achieve it in new construction? A resource-efficient building is one that is not only energy-efficient, but also embodied-energy-efficient. This means that its design minimizes energy consumption, and that the materials used in construction were manufactured and transported with minimal energy, too. These buildings use renewable energy sources such as solar, as well as natural ventilation and daylighting, to as great an extent as possible. They provide healthy living space for occupants through the use of non-toxic materials. In addition, resource-efficient designs minimize waste by using products and materials that are recycled or salvaged, as well as those that minimize water consumption both indoors and out. And, with all that, they're still high quality and affordable. The benefits of taking a resource-efficient approach to new construction include increased marketability, lower operating costs, healthier indoor environments, and a positive impact on the environment. Solplan Review, December 1993/January 1994, The Drawing Room Graphic Services Limited, P.O. Box 86627, North Vancouver, BC, Canada V7L 4L2. Tel. and Fax: (604)689-1841.

The White House "Greening" Plan. Last year, President Clinton promised to make the White House a "model for efficiency and waste reduction" (see "Retrofitting the White House?" HE Sept/Oct '93, p.5).

The newly released "Greening of the White House Report" spells out 50 actions currently underway at the Executive Mansion and the Old Executive Office Building. According to Mark Ginseng, director of the Federal Energy Management Program (FEMP), there is no firm plan to re-install the solar hot water collectors that Ronald Reagan took down, because changes in the central heating plant will make solar much less competitive. However, approved steps include the following: Building envelope/glazings. Because of the historic nature of the building, major upgrades are limited, but plans call for reglazing the third-floor solarium and greenhouse in the Executive Residence with high-performing insulating glass. Energy-Efficient Lighting. Table lamp incandescent bulbs will be replaced with compact fluorescents, including in the president's study and dining room. A West Wing lighting upgrade is to be accelerated. Concealed bathroom incandescents are to be replaced with compact fluorescents, florescent fixtures in the residence service area are to be upgraded with T-8 lamps, electronic ballasts, and occupancy sensors, and so on. HVAC Management. The White House will renovate the residential heating, ventilating, and air conditioning systems by eliminating chlorofluorcarbons; centralizing all cooling operations; upgrading HVAC controls with energy management controls; installing a condensate heat recovery system to preheat domestic hot water; and eliminating all electric reheat functions, replacing them with hot water coils. Under the plan, the efficiency of window air conditioners in the Executive Mansion would be improved. The plan also calls for retrofitting the steam heating system in the Old Executive Office Building. Plug Loads. The White House also plans to install Golden Carrot super-efficient refrigerators, starting with the first one off the production line for the First Family residential quarters; Energy Star computers and energy-efficient copiers, fax machines and other equipment are also on the shopping list. ALFA Energy and Housing Report, March 1994, Alan L. Frank Associates, 9124 Bradford Road, Silver Spring, MD 20901-4918. Tel: (301) 565-ALFA; Fax: (301)565-FAXUS.

Stress Test Panels Prevail. In a recent experiment funded by the U.S. Department of Energy, researchers with the Florida Solar Energy Center found that builders can increase the energy efficiency of their dwellings by using stressed-skin insulated core (SSIC) panels. The panels basically consist of large slabs of polystryene foam sandwiched between two sheets of plywood. Two test houses were built in Louisville Kentucky, with statistically similar amounts of insulation. The control home was built using conventional two-by-four studs fitted with R-13 batts and R-30 attic insulation. The SSIC home featured wall panels with a 35/8-inch core of polystyrene and ceiling panels with 73/8-inch foam core. Preliminary results showed that the SSIC-panel house was more air tight with better insulation values than the control house. The SSCI-panel home proved 12%-17% more energy efficient. The results corroborate preliminary conclusions of a study by Colorado's National Renewable Energy Laboratory (NREL), the Structural Insulated Panel Association and the Modular Building Institute. Popular Science, April 1994, 2 Park Avenue, New York, NY 10016. Tel: (212)779-5000; Fax: (212)779-9468.