Consumer's Union Rates HEPA Vacuums, Roofing & Siding. In the August Consumer Reports, Consumers' Union (CU) rated best-selling vinyl and aluminum sidings. While the CU ignored issues like moisture penetration, environmental effects, and effects on home insulation, it does rate sidings on fading, toughness, attachment strength, and rigidity, all of which are important for building durability and minimal maintenance. CU found that no vinyl siding attached as well as any aluminum siding, and that no aluminum siding was as colorfast as the worst of the vinyl. Attachment strength is most important in stormy areas, and colorfastness is most important in the Sun Belt region. The CU found that the best overall siding was CertainTeed's Monogram, a vinyl product, and the best aluminum siding is Alcoa's Horizon Collection. CertainTeed also did well in the marks of roofing materials, winning top ratings for its Grand Manor Shingle and a Best Buy for XT25. Other Best Buys were Owens Corning Supreme and GAF Royal Sovereign. In the same issue, CU rated high efficiency particulate arresting (HEPA) vacuum cleaners. These vacuums return very little dust to the indoor air, and don't have the depressurization problems of central vacuums. Surprisingly, the best vacuum tested was the inexpensive Hoover Dimension Supreme, which is not advertised as a HEPA vacuum. Next was the Nilfisk GS90, which costs four times as much; the very low-cost Bissell Micro-Lock did relatively poorly. Consumer Reports, August 1997. Consumers' Union, 101 Truman Ave., Yonkers, NY 10703-1057. Tel: (914) 378-2000.

Deciding on Siding. For customers interested in more than price and colorfastness, Environmental Building News (EBN) provides a material selection checklist for siding. Suddenly, vinyl doesn't look so good--it produces hazardous byproducts, and its incineration can release small quantities of toxic chemicals. Wood products, which can last 100 years, come out well, except that they often come from unsustainable logging, and there may be significant waste from on-site trimming. EBN gives a guardedly positive review to the new line of oriented strandboard siding from Louisiana-Pacific, the supposedly waterproof Smart Siding. Environmental Building News, August 1997. EBN, RR 1, Box 161, Brattleboro, VT 05301. Tel: (802)257-7300; Fax: (802)257-7304; E-mail: ebn@ebuild.com.

Solar Financing Through Suppliers. Touting the return on investment is often is a often good way to sell conservation systems to consumers. But then some consumers want to finance their systems. Many small suppliers of solar energy equipment don't have the time or technical ability to provide financing. Soon far more solar suppliers will be able to offer financing through the Solar Energy Industries Association (SEIA) and Volt VIEWTech. A program called Solar Finance will provide consumer loans of $2,500 to $25,000, with repayment times of 5, 7, 10, or 15 years. The loans can be used for solar water heating, pool heating, or photovoltaic systems. Contact: Mac Moore, SEIA. Tel:(202)383-2613; E-mail: mmoore@seia.org. Resnet Notes, August 14, 1997. Residential Energy Services Network, 12350 Old Seward Highway, Suite 208, Anchorage, AK 99515. Tel: (907)345-1930; Fax: (907)345-0540; E-mail: resnet@corecom.net.

Are Efficient Homes Too Tight? Few questions will get people's goat so quickly. Efficiency professionals maintain that their homes perform as good as, or better than, average, but there has been little evidence to indicate whether energy-efficient homes actually have good indoor air quality. A recent study by Lawrence Berkeley National Laboratory examined five new homes in the eastern United States. Researcher Alfred Hodgson found that total volatile organic compound (TVOC) levels varied widely, but had a very high median of 2.4 mg/m3. This compares poorly with homes in a 1991 study by the U.S. Environmental Protection Agency, which found average TVOCs of 0.7 mg/m3. The good news is that formaldehyde was low in all homes. The bad news is that wood, both natural and engineered, appears to be the cause of the high TVOC levels. This makes source control difficult, so energy-consuming mechanical ventilation may be increasingly necessary. Energy Design Update, July 1997. Don Best, 65 Hallwood Dr., Surry, NH 03431. Tel/Fax: (603) 357-5689; E-mail: letters@top.monod.net.

Partial Fuel Switch for Multifamily. The Dual Heat System from Save Energy Engineering is a device that provides hydronic heating off a multifamily building's domestic hot water (DHW) boiler. It is designed for buildings with electric resistance heat in the apartments and an underused DHW boiler. Since most boilers operate at peak efficiency at a high load factor, adding some heating load will increase the efficiency of the boiler while reducing electric demand costs and electric energy bills. The controls in the system make the boiler fulfill the DHW load first, and then the heating load. If the heating load is too big, the controls activate the old electric resistance heaters. Including radiant panels, a circulation pump, installation, controls, and other parts, an apartment can be retrofitted for about $700-$1,200. Preliminary field tests in Canada show peak electric demand coming down 22% and electric energy use down 50%, providing a 20% annual return on investment. Technologies for Utility Success, August 1997. Cutter Information Corporation, 37 Broadway, Suite 1, Arlington, MA 02174-5552. Tel: (800)964-5118; Fax: (800) 888-1816; E-mail: clicata@cutter.com.