Read EDU 2-04 text version

EDU 2-04

2/19/03

3:37 PM

Page 1

The Monthly Newsletter on Energy-Efficient Housing, from Aspen Publishers

Vol. 23, No. 3

March 2003

INDUSTRY NEWS

Grappling With National Green Standards

For several years, the US Green Building Council (USGBC), a private coalition of green building advocates, has successfully promoted a set of green standards for use in commercial construction. The rating system, Leadership in Energy and Environmental Design (LEED), awards points for environmental achievement in five categories: site development, water savings, energy efficiency, materials selection, and indoor environmental quality (see News Briefs, EDU, May 2000). In the category of energy efficiency, for example, a building is awarded points according to the degree to which it exceeds the requirements of ASHRAE Standard 90.1. The LEED program has been widely implemented, especially in the construction of government and educational buildings, but was never intended to cover residential construction. Although several groups promote green residential construction at the local level -- including well-established programs in Austin, Texas and Denver, Colorado -- there are considerable hurdles to achieving a national consensus on green residential construction standards. Because of differences in available resources and climate, what is considered green varies from state to state. For example, the Vermont Built Green program awards points for wood heat and the absence of air conditioning, while the green building program in Scottsdale, Arizona assumes the use of air conditioning and makes no reference to wood heat (see Figure 1). Undeterred by the obvious hurdles, the USGBC has convened a committee to develop a set of national standards for green residential construction (LEED-

IN TH I S IS S U E

INDUSTRY NEWS Grappling With National Green Standards . . . . . 1 Window Manufacturers Fret Over California Ruling . . . . . . . . . . . . . . . . . . . . . . . . . 3 A Powerful Roof . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 NEWS BRIEFS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 RESEARCH AND IDEAS Furnaces In Alaska Are Oversized. . . . . . . . . . . . . 8 Improvements in Fan Motor Efficiency Could Yield Big Savings . . . . . . . . . . . . . . . . . . . . . . . . . 9 Performance of New California Homes Disappoints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 NEW PRODUCTS The World's Best Sill Seal . . . . . . . . . . . . . . . . . . . 11 R-20 Glazing Panels . . . . . . . . . . . . . . . . . . . . . . . . 12 Protecting Exterior Foundation Insulation . . . . . 13 READERS' FORUM. . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 1. -- The new criteria used by the Vermont Built Green program award points for houses with a "wood burning appliance as a primary heat source." [Photo credit: Vermont Castings]

EDU 2-04

2/19/03

3:37 PM

Page 2

2

Energy Design Update®

March 2003

Homes). The committee has written a set of draft standards that will eventually be proposed for ratification by the votes of USGBC members. First, however, the LEED-Homes committee intends to solicit applications from a limited number of home builders willing to participate in a pilot green certification program, probably in 2004. "Then the system will be tweaked to reflect the lessons learned," said Ann Edminster, an architect from Pacifica, California who chairs the committee.

while requiring larger homes to conform to increasingly stringent standards in other categories. In contrast to the Vermont program, the Built Green Colorado program includes no penalties for gigantism, although it does award a modest number of points for houses smaller than 2,000 square feet. The draft LEEDHomes standard follows a path similar to that taken in Vermont. "Anything that I say about the criteria may be reversed through balloting," says Edminster. "But we have developed draft criteria based on a reference house of 2,000 square feet. For every 10% increase in size over 2,000 square feet, you have 10% more environmental impact, so to be certified you would need 10% more points. There is a strong consensus that size matters."

Addressing House Size

A number of rifts divide those struggling to define green building. Most observers agree that any national standard for green homes should assume, as a starting point, compliance with the Energy Star Homes program. But to be green, a home needs to be more than just energy efficient, and green building advocates rarely agree on how to award points for durability, or on which materials are preferred and which are taboo. Especially contentious is the question of whether or not green homes should have an upper limit on size (see "On Green Builders, Dinosaurs, and the Dallas Cheerleaders," EDU, March 2000). Many local green building programs originated as marketing programs established by home builders' associations (HBAs). Since so many American home buyers worship at the altar of square feet, most builders are reluctant to participate in a green building program incorporating size restrictions. Some environmental activists, deriding the timidity of many HBA-founded green building programs, insist that house size cannot be ignored. Among those advocating so-called "deep green" criteria is Richard Faesy, a project manager at Vermont Energy Investment Corporation and a director of Vermont Builders for Social Responsibility. Faesy has been actively involved in the development of criteria for the Vermont Built Green program. "We felt that house size is the overriding factor," says Faesy. "It impacts all of the other building criteria -- energy use, resource and material use, impact on the site -- so we wanted it to play a major role in our rating system. You can build a very energy-efficient house, but if it measures 7,000 square feet, then it really is not, in our minds, a green house." The Vermont criteria reward houses under the benchmark size of 2,300 square feet,

Editor: Martin Holladay Associate Publisher: James O'Shea

Is There A Cry for National Standards?

According to the USGBC Web page, Edminster's LEED Residential Committee "is working with local green building groups to establish a national definition for green homes and low-rise apartment buildings." Yet according to Kim Calomino, the director of Built Green Colorado, one of the largest HBA-sponsored green building programs in the country, "We have not been asked by the LEED-Homes committee to provide input." Edminster acknowledges the philosophical divide between some HBAs and deep green advocates. "Most of the local green building programs have arisen through HBAs, and uniformly they acknowledge that their homes are not the greenest of the green," says Edminster. "Their charter has been to give a way for their exemplary builders to differentiate themselves in the marketplace. It hasn't been to set a standard for what is state-of-the-art in green building -- none of them has pretensions to setting deep green standards. But these programs, to a one, are looking to LEED-Homes to create a third-party definition of what constitutes `green.'" Yet Calomino of Built Green Colorado makes no mention of a need for national standards. "We are quite successful in our own state, and that is all we want to be," says Calomino. "We will continue along that path, with or without a national program." Calomino terms national standards "inevitable." She continues, "What is unique about green building is that the development of green

Production Editor: Mary Susan Ryan

Publisher: Louis Lucarelli Managing Editors: Vicki Dean, Elaine Stattler

Energy Design Update (ISSN 0741-3629) is published monthly by Aspen Publishers, 1185 Avenue of the Americas, New York, NY 10036. (212) 597-0200. Subscription price, $337/one year. © 2003 Aspen Publishers, Inc. All rights reserved. Reproduction in whole or in part without permission is strictly prohibited. Printed in U.S.A. Postage paid at New York, NY, and additional mailing offices. POSTMASTER: Send address changes to Energy Design Update, Aspen Publishers, 7201 McKinney Circle, Frederick, MD 21704. Energy Design Update is sold with the understanding that it is not engaged in rendering legal counseling or other professional services. If legal counseling or other

professional assistance is required, the services of a competent practitioner in the relevant area should be sought. Subscription Services: To order a subscription, call 1-800-683-8437. For customer service, call 1-800-234-1660. To order 100 or more article reprints, contact Journal Reprint Services toll-free at 1-866-863-9726 (outside the US at 1-610-586-9973) or visit their Web site at www.journalreprint.com. Editorial Offices: Martin Holladay, Energy Design Update, P.O. Box 153, Sheffield, VT 05866. E-mail: [email protected]; Tel: (802) 626-1082; Fax: (802) 626-9982.

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 3

March 2003

Energy Design Update®

3

building standards began at the local, grassroots level, addressing local needs. A national program can't do that." Although Edminster's committee was selective in its invitations for input, she wants to leave a door open for broader participation. "My own vision is for the standards to offer recognition at a variety of levels -- bronze, silver, and gold," said Edminster. "I'm reasonably confident that we will be able to craft a system in such a way that we will entice both ends of the spectrum." In areas with established green building programs, there is little evidence that builders see a need for national standards. But in areas not served by an existing program, a national standard would give interested home builders a green benchmark for reference. "There are many regional and local programs that have the potential to expand geographically, but none of them has the scope or desire to do so," notes Edminster.

Grasping At Eels

Many builders approach green construction the way the Supreme Court approaches pornography -- it's hard to define, but you know it when you see it. In fact, the slipperiness of environmental correctness is enough to drive the average standard-writing committee to despair. Edminster admits to the problem in relation to life-cycle analysis of building components. "Personally I don't believe in life-cycle analysis," says Edminster. "It's a red herring, because there are too many incomparables. It will always be comparing apples to oranges -- comparing global warming to stream-bed erosion to eutrophication. We need somehow to value the intuitive, not necessarily quantifiable, processes that brilliant designers go through." Whether brilliant or not, the intuitive nature of the best green construction is not only difficult to pin down, but incorporates value judgments that make some people in the construction industry nervous. "The way that green building fades into social and cultural issues is interesting," says Yost. "Several programs are looking at the best mechanism for capturing the impact of house size. But the question of house size is just bordering on a social issue. I am very sympathetic to those looking at the issue, since the size of your house is one of the most important determinants of its environmental impact, but the worst thing that green building programs can get tagged with now is, `That's social engineering.' I think it is a great debate to have, but having it as part of a program is not very productive." Yet, as many observers have noted, just because defining green construction is difficult, does not mean it shouldn't be attempted. Edminster compares the cultural shift behind the green building movement to a revolution. "I started my green building advocacy working with straw bale and cob builders, and my heart is still there," she says. "I strongly believe we need them to be doing what they are doing, moving where we perceive the boundaries to be. But that is happening one home at a time -- it's not having much measurable benefit -- and that's why these days I am actively working more in the mainstream. In order to successfully mount a revolution, you need the guerillas, you need the moles, you need the people storming the gates, you need the quiet subversives -- you need everybody."

Meeting the Needs of Residential Builders

Some critics doubt that USGBC will fairly represent the interests of residential builders. "From my perspective, having the US Green Building Council -- which represents the commercial, not the residential, construction industry -- develop residential green building guidelines seems a bit outside the structure of the organization and the needs of their membership," says Calomino. Edminster is aware of the problem. "The residential construction industry shares little with the commercial construction industry," she concedes. "With the existing LEED program, the building owner pays fees that cover the cost of certification, and the cost is in the range of thousands of dollars. But there is not a home builder on the planet who is willing to accept a hit of several thousand dollars, so we can't use LEED as a model for funding." Most residential construction budgets are very tight, and home buyers will probably be reluctant to pay for the level of innovation sought by the typical client of a LEED commercial project. "It's not that USGBC is necessarily the best organization to undertake the development of residential green building standards," admits Peter Yost, a senior building research associate at Building Science Corporation, and a member of the LEED-Homes committee. "But there is no one else who has done it."

Window Manufacturers Fret Over California Ruling

The California Supreme Court has ruled that homeowners with construction defect complaints can sue building component manufacturers directly, and can hold manufacturers strictly liable for defective products. The December 4, 2002 ruling in the case of Jimenez v. Superior Court (29 Cal. 4th 473, 2002) will make it easier for California homeowners, whose construction defect suits have, until now, been directed mostly against developers and builders, to bring legal action against manufacturers of doors, windows, and other building components. Until the Jimenez decision, window manufacturers successfully avoided strict liability

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 4

4

Energy Design Update®

March 2003

in California construction defect suits, and several manufacturers' representatives have reacted to the ruling with dismay.

Windows Leaked, Homeowners Allege

The recent ruling arose from a case filed nearly five years ago, when two homeowners, Filipa and Nestor Jimenez, along with dozens of their neighbors, sued two window manufacturers, Viking Industries and T.M. Cobb Company. The suit does not allege that there were errors in window installation. According to the plaintiffs, the windows themselves were defective, causing leaks that damaged stucco, insulation, framing, drywall, paint, wall coverings, floor coverings, and baseboards in their homes (see Figure 2). The homes in question were in two subdivisions, Galleria and Renaissance, in the Scripps Ranch area of San Diego, and were built in 1988 by McMillin Homes.

ers of defective products must pay for injuries or damages caused by those products. Under this doctrine, consumers need not prove negligence or fault, merely that the products were defective. The homeowners in the Jimenez case knew that, as long as the court agreed that strict liability applied, it would be easier to show that the windows were defective than it would be to prove negligence by the developer or window manufacturer. Window manufacturers, however, assert that complaints like those of the Jimenez homeowners should not be directed at window manufacturers, but at developers and builders, since they are the ones with control over how building components are integrated into a house. "In most cases the homeowner doesn't have the right to select the window," notes Ray Bjerrum, president of Merzon Industries, a window manufacturer in Fresno, California. "If a builder decides to pick the cheapest window bid, then the builder should have the responsibility and the liability. Since the builder selected the product and had the right to inspect it, strict liability should stay with the builder." San Diego Superior Court Judge Thomas Murphy ruled on the strict liability issue in favor of the window manufacturers, dismissing the homeowners' suit. At that point the homeowners appealed. On August 1, 2000, the Fourth District Court of Appeal (in Jimenez v. Superior Court, 82 Cal. App. 4th 856, 2000) reversed Judge Murphy's decision, ruling, "Although manufactured windows are installed in and become components of the larger product, a home, they retain their status as products." The appellate court concluded that "manufacturers of defective windows installed in mass-produced homes may be subject to strict products liability." The window manufacturers, Viking and Cobb, then took the issue to the California Supreme Court. In a 6to-1 decision, the court found for the homeowners, ruling that window manufacturers can be held strictly liable for damages cause by defects in their products. Their liability does not cease merely because their windows have been installed in a larger product.

Figure 2. -- The Jimenez plaintiffs allege that the windows installed in their homes were defective. Water entered the wall below this window manufactured by the T.M. Cobb Company, causing damage to the stucco.

According to the plaintiffs' attorney, Stuart Eppsteiner, "The window manufacturers claimed that the windows passed the AAMA 502 sill-track test, but our tests showed they didn't." The case has not yet had a chance to go to trial, since the window manufacturers responded with a motion arguing that since windows are not products under the law, strict liability did not apply, and the suit should be dismissed. The defendants' motion requested adjudication on the applicability of strict liability to building components. "The issue was whether the house was the product or the windows in the house were the product," said Eppsteiner. "If they said the entire house is the only thing that is a product, then window makers would be free of liability for any product they may have built."

Opening the Litigation Floodgates?

The court was unmoved by the window manufacturers' argument that such a ruling would prove disastrous. Writing for the majority, Justice Joyce Kennard noted, "Defendant window manufacturers contend that applying strict liability to them would `open the litigation floodgates.' They predict a massive increase in litigation as manufacturers and distributors of component products used in the mass-production of homes bring actions and cross actions against each other for indemnity and other claims. We are not convinced. The same dire predictions were made in response to

Strict Liability

The strict liability doctrine was established in California in 1963, when a court ruled that manufactur-

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 5

March 2003

Energy Design Update®

5

the original development of strict products liability. As we have explained, the policy reasons favoring strict products liability for component manufacturers are the same as for other participants in the general enterprise of manufacturing and marketing consumer goods, and these interests, including the incentives for improved product safety, outweigh the burden imposed by increased litigation." Advocates for homeowners note that when a window leaks between the sash and the frame, rather than because of installation errors, it is entirely appropriate for the window manufacturer to be liable. "The ruling apportions the risk to the actual component maker rather than shifting the risk to the developer," says Eppsteiner. But window manufacturers are spooked at the increase in liability arising from Jimenez. "Now the homeowner has the right to go straight to the manufacturer and sue for strict liability," says Bjerrum. Manufacturers are especially worried that their liability may extend to the distant past, allowing homeowners to sue for defects in windows installed 25 or 30 years ago. Moreover, the Supreme Court ruling may contradict elements in California's "Right to Repair" law, SB800, which took effect on January 1, 2003. "Because window manufacturers are now subject to strict liability, they are not eligible to use some of the defenses spelled out under SB800," says Rich Walker, executive vice president of American Architectural Manufacturers Association (AAMA), a window manufacturers' association.

Jimenez ruling is at odds with SB800. These ambiguities remain to be clarified by future rulings.

When the Wrong Window Is Chosen

Some window manufacturers note that just because a window leaks does not mean it is defective. "We design products with different design limitations and different water intrusion levels," says Bjerrum. "It is the responsibility of the builder and the architect to pick a window that is right for that location -- for example, a house in a high-wind area. But according to the Jimenez decision, even if the wrong window was chosen, the homeowner can say the window needs to be replaced because it leaked." In response, Eppsteiner advises window manufacturers to pay more attention to where their windows are sold and delivered. "The window makers and the chain of distribution need to make sure that their windows go into an appropriate location," he says. "They need to think about where their products are appropriate for." Manufacturers envision a worst-case scenario in which dozens of lawsuits assail manufacturers for producing defective materials, including shingles, nails, and screws. According to Walker, "Some window manufacturers are contemplating withdrawal from the California market altogether." As window makers note, the most common causes of leaks under windows are not window defects but installation errors. "In my view, 90 percent of what people call window leaks are really wall leaks," says Bjerrum. "But you never hear anyone talk about wall leaks. I know that in Chicago they are putting vinyl windows on top of OSB, then installing vinyl siding without any building paper, and saying it is good to go. Is the window manufacturer supposed to be out there telling the builder that he is building a wrong house?" In fact, window manufacturers may conclude that it is in their long-term interest to do exactly that. Since Americans rarely exercise restraint when offered the opportunity to sue, Jimenez will almost certainly lead to more litigation. To protect themselves, window manufacturers may be forced to institute changes that will benefit everyone -- manufacturers, builders, and homeowners. After all, when walls stay dry, the chances of litigation are greatly reduced. Window manufacturers may find it necessary not only to build windows that don't leak, but also to find more ways to help builders install them in a leak-free manner. Some window manufacturers are already doing just that by participating in AAMA's Installation Masters program (see EDU, May 2000). Jimenez might finally lead to the demise of the notorious one-paragraph window sticker with terse installation instructions, along the lines of: "Apply caulk to back of nailing

Senate Bill 800

In September 2002, the California legislature passed SB800 after lobbying by builders who complained that homeowners were suing them for problems that had never been brought to their attention, denying the builders an opportunity to make repairs and nip the problem in the bud. The bill establishes steps that must be followed before a construction defect suit can be filed, and includes definitions of "functionality standards" and "actionable defects." According to SB800, if a homeowner discovers any actionable defects (within a period of time that varies depending on the nature of the defect), the homeowner may sue, but only after first notifying the builder of the problem and allowing repairs. Moreover, SB800 puts the burden on the homeowner to maintain the house properly. Most builders were pleased at SB800's "right to repair" provisions. According to Bjerrum, "SB800 cuts down on smorgasbord lawsuits." But according to one interpretation of SB800, the bill does not define a window as an independent product, but assumes it is merely a component of a larger product. If this interpretation is correct, then the recent

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 6

6

Energy Design Update®

March 2003

fins. Shim sill level. Check diagonals to be sure unit is square. Nail through fins with galvanized roofing nails." The more forward-looking window manufacturers have already realized the need to provide installers with instructions detailing recommended

methods for the installation of building paper and flexible flashing. Reputable manufacturers should also find some solace in the fact that even under the Jimenez ruling, homeowners cannot prevail in litigation unless they are able to prove that a window is defective.

A Powerful Roof

Last August, a roofing crew from Solar Plexus of Missoula, Montana spent a week installing a spectacular photovoltaic (PV) roof on a new timber-frame barn in Woody Creek, Colorado (see Figure 3). The entire south slope of the barn's gable roof is covered with a type of PV roofing shingles called Sunslates. Each Sunslate is made by adhering six glass-covered crystalline PV cells to the lower (exposed) portion of a fiber-cement "slate." Sunslates, like some conventional concrete tiles, are installed on battens (see Figure 4). Since one Sunslate costs $90 to $100, the material cost for the 1,540 Sunslates used on the Woody Creek job was about $138,000. The installed cost of the roof, including wiring, inverters, and other balance-of-system components, was close to $250,000. In bright sun, the grid-connected PV roof generates between 18 and 20 kilowatts of electricity (see Table 1). The homeowner, billionaire Sam Wyly, intends to use the barn for equipment storage and a workshop. The PV system was designed by Ed Eaton, an instructor and PV system installer for Solar Energy International of Carbondale, Colorado. "The shingles are really cool from an aesthetic standpoint," says Eaton. "It's basically a glass roof."

For more information, contact: Atlantis Energy Systems, 4610 Northgate Blvd, Suite 150, Sacramento, CA 95834. Tel: (916) 438-2930; Web site: www.atlantisenergy.com. Solar Energy International, P.O. Box 715, Carbondale, CO 81623-0715; Tel: (970) 963-8855; Fax: (970) 9638866; E-mail: [email protected]; Web site: www.solarenergy.org. Solar Plexus, 130 W. Front Street, Missoula, MT 59802. Tel: (406) 721-1130; Fax: (406) 721-1130; E-mail: [email protected]; Web site: www.solarplexus1.com.

Table 1 -- Wyly Roof Specifications

Size of roof slope covered with PV shingles Number of Sunslates installed Exposure of each Sunslate Electrical output of each Sunslate Number of Sunslates per string Electrical output of each 22-slate string 27 feet by 81 feet (2,187 square feet) 1,540 1.2987 square foot 2.929 volts at 4.54 amps (13.3 watts) 22 64.4 volts at 4.54 amps (292 watts)

Figure 3. -- The entire south slope of this barn's gable roof is covered with Sunslates -- fiber-cement roofing shingles incorporating photovoltaic cells.

Figure 4. -- Like concrete roofing tiles, Sunslates are installed over battens.

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 7

March 2003

Energy Design Update®

7

NEWS BRIEFS

NORWALK, CT -- The Building America program has ratcheted up its energy-efficiency goal from 30% savings over the 1993 Model Energy Code (MEC) to 40% savings. According to a press release from the Consortium of Advanced Residential Buildings (CARB), "This increase in efficiency may not seem to be a big jump, but it represents a real challenge for many homebuilders in terms of making the grade cost-effectively." ITHACA, NY -- Energy produced from renewable sources (solar, wind, biofuels, and hydropower) can replace no more than 50% of the fossil fuels now consumed in the US, according to a new study by ecologists at Cornell University. Such a scenario, which the researchers call "full implementation" of renewable sources of energy, would take up 17% of US land area. The researchers' findings are reported in the December issue of the journal BioScience. "The biggest problem is our extraordinary rate of energy consumption to maintain our standard of living -- or should we say, standard of burning," said Cornell professor of ecology David Pimentel. "We wish this had turned out differently -- we really do -- but it's hard to argue with the facts." Full implementation of wind resources would require ramping up from the current level of 6.6 billion kWh per year to 777 billion kWh per year. "The only way to change the equation -- to make renewable energy sources go further and kick our addiction to fossil fuels -- is to reduce energy consumption, and that means conservation," said Pimentel. "Other developed countries have proved that high productivity and high standards of living can be achieved with the use of half the energy expenditure of the United States." TRENTON, NJ -- New Jersey Governor James McGreevey made an impassioned call for curbs on sprawl in a January 14 speech. "Let me say to those who profit from the strip malls and McMansions," said Governor McGreevey, "If you reap the benefits, you must now take responsibility for the costs." According to the New York Times, the governor called for building moratoriums and increased development fees, promising state help to town officials fighting "developers with deep pockets" who "effectively bully unwilling taxpayers into submission." BOSTON, MA -- Currently 22 gas utilities and energy companies offer rebates to residential customers for the installation of high-efficiency (over 90% AFUE) gas furnaces, according to a press release from the Consortium for Energy Efficiency (CEE). The CEE calculates that an investment of $800 by a Boston homeowner to cover the incremental cost of an 90% AFUE furnace compared to a 78% AFUE furnace will yield energy savings of $104 per year, for a simple payback period of 7.7 years. These payback numbers improve when rebates (typically $200 to $400) are available from the local gas utility. For more information, contact the Consortium for Energy Efficiency (Tel: 617-589-3949; Web site: www.cee1.org). PORTLAND, OR -- Residential solar thermal systems provide a much better payback than photovoltaic (PV) systems, noted Steve Still, an energy management specialist for the Eugene (Oregon) Water and Electric Board, at the Northwest Solar Summit last October. In a story reported by Con.Web, a monthly online newsletter produced by Energy NewsData in Seattle, Still said that PV represents "the favorite sun" these days, in spite of the fact that a $2,000 investment in a solar thermal system can produce the same energy savings as a $15,000 PV system. ALBANY, NY -- Announcing his desire to make New York a national leader in renewable energy usage, New York Governor George Pataki announced during his annual State of the State address that New York is committed to assuring that within ten years, 25% of all electricity bought in the state will be generated from renewable energy sources. WASHINGTON, DC -- Around the world, biodiversity is threatened by a housing boom fueled by a reduction in the number of people per household, according to a study conducted by scientists at Michigan State University and Stanford University, and reported in the January 12 online edition of the British science journal Nature. The study of 141 countries concludes that rising divorce rates and shrinking household size are worldwide trends contributing to housing sprawl. Even in areas with declining population, the report notes, the number of households continues to grow. According to Stanford University ecologist Gretchen Daily, "Urban and suburban sprawl are accelerating faster than population growth is decelerating." The study's co-author is Jianguo Liu, an associate professor of fisheries and wildlife at Michigan State. "Having fewer people in more households means using more resources and putting more stress on the environment," said Liu. "The issue of the number of households and their impact on the environment basically has been ignored. It was even difficult to unearth the data." UPPER MARLBORO, MD -- Using an on-demand electric water heater connected to parallel PEX tubing can save 14% on energy costs in a high-use home compared to using an electric tank-type water heater connected to standard tree-configured copper tubing, according to a study by the National Association of Home Builders Research Center. A low-use home shows even greater energy savings of 34%. The researchers' conclusions were based on direct measurements and computer simulations. The report,

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 8

8

Energy Design Update®

March 2003

"Performance Comparison of Residential Hot Water Systems," was sponsored by the National Renewable Energy Laboratory. The report is available online at www.toolbase.org/Docs/MainNav/Energy/3733_fina lreport-NRELversion.pdf. NORWALK, CT -- An energy-saving "variable deadband" thermostat developed as part of the Building America program has earned a patent for Steven Winter Associates. The deadband is the temperature range between the cut-in and cut-off points of a thermostat. The new thermostat maintains a narrow deadband during peak heating and cooling periods, and adjusts itself to a wider deadband during the milder outdoor temperatures of spring and fall. A wider deadband during spring and fall saves energy by reducing equipment short-cycling. Home Automation Incorporated (HAI) of New Orleans, Louisiana, has produced prototypes of the new invention. For more information, contact Steven Winter Associates at (203) 857-0200. AUBURN HILLS, MI -- Uni-Solar (Bekaert ECD Solar Systems) has begun promoting its peel-and-stick photovoltaic (PV) laminate product for use with membrane roofing, including EPDM and PVC roofing. Until recently, Uni-Solar's PV laminates were marketed for use only with standing-seam metal roofing. UniSolar's PV laminates are 15-inch-wide flexible PV modules adhered to a peel-and-stick backing, and are available in lengths up to 18 feet. A Uni-Solar representative admits that at the end of the membrane roofing's life -- often around 20 years -- any PV modules adhered to the roofing may not be salvageable. For more information, contact Uni-Solar at (800) 8433892 or www.uni-solar.com. WASHINGTON, DC -- A Connecticut man has been sentenced to six and a half years in prison for smuggling ozone-depleting chlorofluorocarbons (CFCs) into the US. According to a report from the Environmental News Service (http://ens-news.com), Barry Himes made millions of dollars selling smuggled CFCs for use in refrigeration systems and air conditioners. Himes' coconspirator, John Mucha, received a sentence of four and a half years. In order to discourage the use of CFCs, the chemicals are subject to a federal excise tax of $5 per pound. Himes and Mucha avoided the taxes

by smuggling hundreds of tons of CFCs into the US. According to John Suarez, an assistant administrator for enforcement at the Environmental Protection Agency, "As these defendants learned the hard way, CFC smugglers get caught, prosecuted, fined, and sent to federal prison. This settlement sends a clear message that pollution doesn't pay." OTTAWA, ONTARIO -- With a stroke of Prime Minister Jean Chrétien's pen, Canada ratified the Kyoto Protocol regulating greenhouse-gas emissions on December 16, 2002. Canada's ratification brings the number of countries that have ratified the treaty to 100. Canada's move came on the heels of New Zealand's ratification a few days earlier. During the New Zealand signing ceremony, Prime Minister Helen Clark said, "Climate change is a global problem, and a concerted international effort is required to combat it." For the Kyoto Protocol to enter into force, two conditions must be met. The first trigger is ratification by 55 governments, a requirement that was met in early 2002. The second trigger requires that the ratifying governments must include developed countries representing at least 55% of that group's 1990 carbon dioxide emissions. Ratification of the treaty by Russia, expected soon, would satisfy the second trigger and bring the treaty into force. WASHINGTON, DC -- An 8.7-kW grid-connected photovoltaic (PV) system was installed on the roof of a maintenance building on the White House grounds in August 2002. The 67 roof-mounted PV modules were installed as part of a renewable energy program administered by the National Park Service. Although Jimmy Carter directed the installation of solar thermal panels on the White House roof in the 1970s -- panels later removed by Ronald Reagan -- this is the first time that PV modules have been installed at the White House. The modules were manufactured by Evergreen Solar of Marlboro, Massachusetts. QUOTE WITHOUT COMMENT -- "The catastrophic failure of 109 SIPs-built residential units in Juneau, Alaska highlights the challenges associated with building with SIPs. ... In many respects, Juneau is the Challenger disaster of the SIP industry." -- John D. Cooper, "A Serious Challenge to a New Building Technology," in the January/February 2003 issue of Home Energy.

RESEARCH AND IDEAS

Furnaces In Alaska Are Oversized

A recent study has shown that the average furnace installed in a new home in Anchorage, Alaska is oversized by 121%. The study was conducted by Phil Kaluza, a researcher with Arctic Energy Systems, and was sponsored by the Cold Climate Housing Research Center through a grant from Alaska Housing Finance Corporation. Kaluza looked at 19 Anchorage-area homes with forced-air heating systems. All of the homes were

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 9

March 2003

Energy Design Update®

9

less than seven years old. During the winter of 2001-2002, the homes were equipped with data loggers to monitor indoor temperature, outdoor temperature, and furnace run-time. Once furnace runtime data were collected, the data logger software performed a linear regression analysis to correlate outdoor temperature with furnace output. This regression model was then used to predict furnace output at the design temperature.

Sizing By Rule of Thumb

According to Kaluza, heating contractors in the Anchorage area commonly install residential furnaces using a rule of thumb of 40 BTUH per square foot of floor area. Indeed, in the 19 studied houses, the capacity of the installed furnaces averaged 42.8 BTUH per square foot. Yet furnace run-time calculations indicated that the average heat load of the 19 houses at design temperature was actually 19.7 BTUH per square foot. The "least oversized" furnace was oversized by 66%, while the most oversized furnace was oversized by 223%. Furnace oversizing increases the initial cost of a heating system. Moreover, an oversized furnace tends to short cycle, shortening equipment life and reducing efficiency. Because an oversized furnace usually has higher than necessary airflow, it also reduces comfort. "Reducing airflow rates by 30%-60% would significantly reduce the pressure imbalances found in a home, and subsequently reduce the amount of potentially damaging air leakage into and out of the home," notes Kaluza. Ironically, the information necessary to size a furnace properly is readily available to Anchorage heat-

ing contractors. Since Alaska adopted its Building Energy Efficiency Standards in 1992, most new homes in the Anchorage area have received an energy rating by a certified rater using AkWarm software. AkWarm's features include a heat-loss calculation. "All new homes constructed within the municipality of Anchorage must submit a design heat-loss calculation for plans review; these are either the AkWarm report or a separate worksheet provided by the municipality," writes Kaluza. "Unfortunately, few, if any, of the local residential heating system contractors utilize the available design heat load reports or utilize their own design tools to properly size heating systems." Convincing heating contractors and builders to size furnaces accurately can be difficult. "If a builder wants to try downsizing the furnace, the heating contractor usually says, `You can put in anything you want, but I won't guarantee it,'" says Kaluza. "Then the builder gets nervous." Ultimately, though, proper equipment sizing is in the builder's interest. "I keep telling the builders to ask the heating contractors for a heat-loss calculation for the house," says Kaluza. "I'm sure that if they ever did, most of the heating guys would just drop dead right there in the driveway." The full report, Over-Sizing of Residential Forced-Air Heating Systems in Southcentral Alaska Homes, is posted on the Web at www.cchrc.org/Final%20Report% 20RHE.pdf. For more information, contact the Cold Climate Housing Research Center at 515 Seventh Avenue, Suite 340, Fairbanks, AK 99701; Tel: (907) 457-3454; Fax: (907) 457-3456; Web site: www.cchrc.org.

Improvements in Fan Motor Efficiency Could Yield Big Savings

Because the annual fuel utilization efficiency (AFUE) calculation for furnaces considers only fossil-fuel use, not electricity use, fan motor efficiency receives little attention from furnace manufacturers. Moreover, air conditioner manufacturers have little incentive to improve fan motor efficiency, since the existing seasonal energy efficiency ratio (SEER) test protocol includes default values for fan motor power consumption that differ from actual fan motor current measured in field studies. "Residential HVAC Fans and Motors Are Bigger than Refrigerators," a paper presented at the 2002 ACEE Summer Study on Energy Efficiency in Buildings, examines the economics of improvements in furnace fan motor efficiency. Authors Harvey Sachs, Toru Kubo, Sandy Smith, and Kalon Scott note that electronically commutated motors (ECMs) are 15% to 30% more efficient at high speeds than permanent split capacitor motors (the type of motor installed in 90% of all residential air handlers). At low speeds, ECMs are even more impressive, achieving twice the efficiency of permanent capacitor motors. The study's authors note that investments in improved fan motor efficiency will yield greater energy savings than investments in further AFUE improvements. Although most furnace manufacturers offer ECMs for only their top-of-the-line equipment, ECMs are cost-effective in all regions of the country, with a payback period varying from two to three years (see Table 2, page 10). Switching to an efficient fan motor would save the typical homeowner 790 kWh per year, more than the consumption of a 2001-compliant refrigerator. But, in the absence of a regulatory nudge from Washington,

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 10

10

Energy Design Update®

March 2003

furnace manufacturers show little interest in making ECMs available to all furnace buyers. The study is included in the 2002 ACEE Summer Study on Energy Efficiency in Buildings, available on CD-ROM for

$115 from American Council for an Energy-Efficient Economy, 1001 Connecticut Avenue, NW Suite 801, Washington, DC 20036. Tel: (202) 429-8873; Fax: (202) 429-2248; E-mail: [email protected]; Web site: www.aceee.org.

Table 2 -- ECM Fan Cost, Savings, and Payback

Incremental cost to homeowner for an ECM fan Average annual kWh savings per residence Average annual savings, assuming $0.08 / kWh Estimated payback period in cool climate Estimated payback period in average climate Estimated payback period in hot climate $140 790 kWh $63 2.0 years 2.4 years 2.5 years

Table 2. -- Manufacturers typically pay about $110 for an electronically commutated motor (ECM) compared to $24 for a less efficient permanent split capacitor motor. For the homeowner, the incremental cost for an ECM is assumed to be about $140.

Performance of New California Homes Disappoints

A performance study of 30 newly built California homes has once again indicted the usual suspects: excessive duct leakage, low airflow over cooling coils, and sloppy installation of fiberglass batts. According to the study, authored by Marc Hoeschele, Rick Chitwood, and Bill Pennington, and sponsored by the California Energy Commission, "Observed defects were numerous." The performance problems uncovered by the study were particularly disappointing in light of the fact that all 30 houses were enrolled in programs promoting building-envelope improvements and duct tightness. The researchers noted, "Fourteen of the 30 houses participated in new construction programs that required duct testing. Six were part of a municipal energy efficiency program where a sampling of installed duct systems were tested, and ten involved voluntary builder efforts to install tight ducts where duct testing was not a required component." The slab-on-grade houses were located in southern California and the Central Valley. Among the study's findings: · Average air flow over the air conditioner coils was 349 cfm per ton of cooling -- 13% below the industry standard of 400 cfm per ton. · Most houses had room-to-room airflow deviations from HVAC design requirements: "Not only was total airflow typically low, but also airflow was poorly distributed within the house." · Most buildings had air barrier defects resulting in interior walls and building cavities (soffits and fireplace chases) that were well connected to unconditioned space. · The average measured duct leakage was 7.7% of fan flow -- 28% higher than the hoped-for target of 6% duct leakage. Only 13 of the 32 duct systems had duct leakage at or below 6%. · Duct leakage to outside, on average, measured 81% of total duct leakage. The quality of the air sealing work and insulation installation were particularly disappointing. The California Energy Commission's "envelope protocols," which include standards for air sealing and insulation installation, were widely ignored. The following standards were met in only 10% to 30% of the houses examined: · Rim joist insulation cut to fit · Kneewalls and skylight wells insulated to R-19 · Weatherstripping installed at attic access hatch · Air sealing performed around tub and shower drains. Not a single builder managed to implement any of the following standards: · Insulation batts cut to fit around wiring, plumbing, and electrical boxes · Skylight shaft batts installed in contact with the drywall

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 11

March 2003

Energy Design Update®

11

· Installation of a facing to limit air intrusion on the attic side of kneewall and skylight well batts. The study, "Diagnostic Performance Assessment of Thirty New California Homes," is included in the 2002 ACEE Summer Study on Energy Efficiency in

Buildings, available on a CD-ROM for $115 from American Council for an Energy-Efficient Economy, 1001 Connecticut Avenue, NW Suite 801, Washington, DC 20036. Tel: (202) 429-8873; Fax: (202) 429-2248; E-mail: [email protected]; Web site: www.aceee.org.

NEW PRODUCTS

The World's Best Sill Seal

An ingenious new sill seal product called Triple Guard has been developed by Protecto Wrap, a manufacturer of rubberized asphalt membranes and flexible flashings. Like conventional sill seal, Triple Guard includes a gasket of closed-cell polyethylene foam. But to better seal the gaps of an irregular concrete foundation, Triple Guard's foam has been increased in thickness from the typical 1/4 inch to 3/8 inch. This polyethylene foam is joined with a layer of 20 mil peel-and-stick rubberized asphalt, so that the gasket adheres to the top of the concrete wall. Triple Guard also includes a 4 3/4-inch-wide peeland-stick flange at a 90-degree angle to the foam gasket, forming a T-shaped cross-section. The bottom half of this vertical flange is adhered to the outside face of the concrete wall (see Figure 5). After the walls are raised and sheathed, the upper half of the flange is adhered to the wall sheathing, totally blocking air infiltration. Last year, senior research engineer Jan Kosny tested Triple Guard sill seal at the Oak Ridge National Laboratory. Kosny's test compared the performance of a variety of sill-seal options on a 9'6" long wall section including a concrete stub wall, a sill plate, and floor framing with a band joist. When sealed with conventional foam sill seal, the gap between the concrete and the mudsill had an equivalent leakage area (ELA) of 3.6 square inches. Triple Guard sill seal, however, resulted in an ELA of only 0.3 square inches -- a 91.7% reduction in air leakage. Kosny was surprised by Triple Guard's tenacity. "The last sealant we tested was the Protecto Wrap product," he said. "After we were done with our testing, we had some questions about some of the results, and we wanted to repeat some of the testing. So we said, `Let's remove the Protecto Wrap from the concrete and test the other sealant.' But can you believe that three people couldn't take off a ten-footlong piece of Protecto Wrap in three hours? It's a very tough product." Kosny found Triple Guard's performance impressive. "This product gives almost 100 percent protection against air leakage, as well as moisture leakage in two directions -- horizontal and vertical," said Kosny. "This is a great product." Triple Guard is sold in 25-ft. rolls in two different sizes. The smaller size, intended for use with 2x4 sill plates, has a 3 1/3-inch wide foam strip, and costs about $22 per roll. The larger size (for 2x6 sill plates) has a 5 1/2inch-wide foam strip and costs about $34 per roll. Protecto Wrap also sells a product called Energy Plate Liner, a gasket for use between the bottom plate of a wall and the subfloor. Energy Plate Liner is a strip of 1/4-inch-thick closed-cell polyethylene foam adhered to a strip of peel-and-stick rubberized asphalt. It is an effective and convenient way to seal air leaks under wall plates. Energy Plate Liner comes in two sizes (3 1/2 or 5 1/2 inches wide). For more information, contact: Protecto Wrap, 2255 South Delaware Street, Denver, CO 80226. Tel: (800) 759-9727 or (303) 777-3001; Fax: (303) 777-9273; Web site: www.protectowrap.com.

Figure 5. -- Triple Guard's foam sill seal is bonded to a rubberized asphalt membrane with a T-shaped cross section. The peel-and stick membrane keeps the foam adhered to the concrete, and also provides a tenacious seal to the plywood sheathing and the outside face of the concrete foundation.

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 12

12

Energy Design Update®

March 2003

R-20 Glazing Panels

The Kalwall Corporation, a manufacturer of translucent fiberglass panels, has introduced a new glazing panel with an R value of 20. Kalwall's R-20 panel transmits 20% of visible light, more than Kalwall's regular R-10 glazing panel. This amazing performance is achieved by filling the insulating space in the 2 3/4-inch-thick panels with silica aerogel, a low-density (6.5 pounds per cubic foot) translucent foam made from compounds of silicon dioxide. This silica aerogel achieves R-8 per inch while still transmitting a significant percentage of visible light. Kalwall obtains the silica aerogel insulation used in its panels from the Cabot Corporation, a chemical manufacturer with headquarters in Billerica, Massachusetts. (The Cabot Corporation is not connected with Cabot Stains of Newburyport, Massachusetts.) "As a company, we have been interested in aerogels for 35 years," says Bruce Keller, Kalwall's vice president for sales and marketing. "We've invested a lot of time and money working with government labs and folks throughout the world to see if we could help develop this material for the construction industry. About seven or eight years ago, the Cabot Corporation began working on aerogels. And lo and behold, they came up with a process for manufacturing aerogels at a fraction of what it used to cost." Cabot's aerogel product, dubbed "Nanogel," is being produced at a new factory in Frankfurt, Germany. The first Kalwall R-20 panels were recently used to roof a swimming pool at the Comfort Inn in Manchester, New Hampshire (see Figure 6). Kalwall's new R-20 panels will allow the design of energy-efficient buildings bathed in diffuse natural light (see Figure 7). "The solar heat gain coefficient is very low, so even if you use it on the south side, you don't have to worry about raising the temperature of your building," said Keller. The most likely residential applications for Kalwall R-20 panels will be for skylights and sunrooms. For now, Kalwall R-20 panels are expensive, and are available only on a limited basis. Each manufacturing run is scheduled as a custom order. The least expensive Kalwall R-20 panels are standard 4-ft.-wide skylights, in lengths from 4 feet to 20 feet. Since the price is about $40 to $50 per square foot, a 4'x4' skylight will cost about $800. One factor to keep in mind: since snow is unlikely to melt quickly from an R-20 panel, homeowners should be willing to accept dim light during snow season, or should be adept at using a long-handled snow rake. For more information, contact: Cabot Corporation, 157 Concord Road, Billerica, MA 01821. Tel: (978) 670-8018; Fax: (978) 670-7045; Web site: www.cabot-corp.com/nanogel. Kalwall Corporation, P.O. Box 237, Manchester, NH 03105. Tel: (800) 258-9777 or (603) 627-3861; Fax: 603627-7905; Web site: www.kalwall.com.

Figure 6. -- The translucent Kalwall panels that form the new roof over the Comfort Inn swimming pool in Manchester, New Hampshire have an R value of 20.

Figure 7. -- About 20% of the visible light striking Kalwall R-20 panels is transmitted to the interior of the building.

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 13

March 2003

Energy Design Update®

13

Protecting Exterior Foundation Insulation

In areas of the country where termites are not a problem, exterior foundation insulation usually performs better than interior insulation. Although termites have been reported as far north as Toronto, rigid foam has been successfully used for many years to insulate the exterior of foundations in the colder regions of the US and most of Canada. Currently, the International Residential Code (R324.4) prohibits the use of below-grade rigid foam at the exterior of foundations in six states (Alabama, Florida, Georgia, Louisiana, Mississippi, and South Carolina) and in portions of two others (California and Texas). faced with the problem of how to protect the above-grade insulation from UV rays and physical abuse from baseballs and weed-whackers (see Table 3). The exposed foam can be covered with aluminum coil stock, although the material tends to buckle and dent. A more durable option is pressure-treated plywood, although some homeowners may deem the material unattractive. Some builders have used fiber-cement panel siding to protect foundation foam. Only one fiber-cement siding manufacturer (MaxiTile of Carson, California; 800-338-8453; www.maxibuildingproducts.com) permits the installation of their panel product (Maxipanel) in contact with the soil. Maxipanel siding is available in 4'x8', 4'x9', and 4'x10' panels. A James Hardie technical representative stated that the use of their fiber-cement panel siding (Hardipanel) to

A Variety of Options

If the use of exterior below-grade foam raises no red flags from local code officials or entomologists, a builder is still

Table 3 -- Materials Used To Protect Exterior Foundation Insulation

Manufacturer 1/2-inch pressure-treated plywood Fiber-cement panel siding Quikrete #1219 Foam Coating Stone Mason Instant Foundation Insulation Coating Styro Tek brush-on stucco coating Tuff II trowel-on stucco coating Insul-Cap (vinyl) Various MaxiTile, James Hardie Quikrete U.S.E. Hickson Styro Tek Styro Tek Price per square foot $0.56 to $0.65 $0.75 NA $0.17 for one coat; $0.34 for two $0.74 for one coat; $1.48 for two $0.77 for one coat, including cost of fiberglass mesh $1.19 $1.23 $1.15 Thickness 1/2 inch 5/16 inch 1/16 inch 1/16 inch per coat 1/16 inch per coat 1/8 inch per coat Size 4'x8' sheets 4'x8', 4'x9', and 4'x10' sheets Sold in 40-pound pails Sold in 50-pound bags Sold in 5-gallon pails Sold in 5-gallon pails 12, 18, or 24 inches wide by 40 feet long 12, 24, or 48 inches wide by 50 feet long 12 or 24 inches wide, 50 feet long

Wisconsin Poured Wall Products Nudo Products Diversified Composities

0.040 inch 0.060 inch 0.060 inch

Ground Breaker (fiberglass) Insul-Guard 2 (fiberglass)

Table 3. -- Above-grade exterior foundation insulation can be protected with pressure-treated plywood, fiber-cement panel siding, stucco coating, vinyl, or fiberglass panels.

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 14

14

Energy Design Update®

March 2003

cover foundation insulation is "unwarranted." Yet the James Hardie Web site recommends the use of Hardipanel as mobile-home skirting. Other fiber-cement siding manufacturers, including Cemplank (manufacturer of Cempanel siding) and CertainTeed (manufacturer of FiberTect panel siding), categorically advise that their products must not be installed in contact with soil.

lon pails, either as part of a kit including a pail of dry powder and a brush ($59) or as a premixed, ready-toapply product called Styro Flex. Styro Tek's more durable trowel-on product, Tuff II, is an acrylic formulation sold premixed in 5-gallon pails ($89). Before troweling on a 1/8-inch coat of Tuff II, the entire surface of the exposed foam should be covered with a layer of fiberglass mesh. Styro Tek sells a sticky type of fiberglass mesh in three different widths: the 2-inch and 6-inch widths are used to cover seams, while the 12-inch width (about $0.33 per square foot) is used to cover large areas of foam. U.S.E. Hickson's product, "Stone Mason Instant Foundation Insulation Coating," is distributed in the US by Menard's (715-876-5911; www.menards.com). The product, which is gray, is described as a "a fiberreinforced, polymer-modified, cement-based product." A 50-pound bag, which covers 120 square feet with a single 1/16-inch coat, is a bargain at $20. Because any stucco product installed directly over foam -- especially one installed without full fiberglass mesh reinforcement -- has a limited ability to withstand physical abuse, such coatings often chip and flake. "The cement is being used like a paint, so if you give it a good whack, it's hard to say what will happen," says Murray Yake, a representative from U.S.E. Hickson. "Remember, the foam underneath is not very rigid."

Stucco Coatings

One of the least expensive -- and least durable -- ways to protect foundation insulation is with a cementitious coating or stucco "wash." At least three manufacturers -- Quikrete, Styro Tek, and U.S.E. Hickson -- sell stucco formulations specifically designed to cover exposed foundation insulation. All three manufacturers recommend that the foam panels be roughed up with a wire brush before the stucco is applied. Quikrete sells three fiberglass-reinforced stucco products that can be used to cover exposed foundation insulation. These products are Foam Coating (Product #1219), Foundation Coating (Product #1215), and FiberglassReinforced Stucco (Product #1216). A Quikrete Web page (www.quikrete.com/diy/project_42.html) provides recommended details for installing these products over foundation insulation. After the foam panel seams have been covered with fiberglass mesh tape, one of the Quikrete products can be applied with either a brush or a trowel to a thickness of 1/16 inch. Styro Tek offers both brush-on and trowel-on versions of stucco for foundation insulation. The brush-on product, described by the manufacturer as "a polymermodified cementitious coating," is installed in the same way as the Quikrete products. After installing fiberglass mesh tape over the foam seams, the brushon coating is applied directly to the foam (see Figure 8). This "Original Brush-On Coating" is sold in 5-gal-

Vinyl Panels

At least one manufacturer, Wisconsin Poured Wall Products, manufactures a vinyl flashing material suitable for covering exposed foam. The product, InsulCap, resembles vinyl siding. The material is slate-gray, and comes in 40-foot rolls, in a variety of widths (12, 18, or 24 inches). A 12-inch wide roll sells for $47.60. The manufacturer also offers 1-inch and 2-inch vinyl Jchannel for trimming around windows. This J-channel is a useful trim product, no matter which material is being used to protect the foam, although some installers have reported problems due to thermal expansion of the vinyl. The Insul-Cap manufacturer also sells "arrow tag anchors" to secure Insul-Cap to the underlying foam insulation.

Fiberglass Panels

Two manufacturers make fiberglass panels designed to protect foundation insulation (see Figure 9). Fiberglass panels are certainly more durable than stucco, and are probably more durable than vinyl. One of these products, Insul-Guard, has been around for several years (see EDU, May 1996). The current version, InsulGuard 2, is a gray, 0.06-inch-thick fiberglass panel that comes in 50-foot rolls, either 12 or 24 inches wide. The installer can choose between two textures, since one side is smooth, and the other is rough. The top of the Insul-Guard is usually mechanically fastened to the sill

Figure 8. -- Stucco can be installed directly over extruded polystyrene insulation, as long as the panel seams have been taped with fiberglass mesh. Styro Tek, the manufacturer of this brush-on coating, recommends roughening the surface of the foam with a wire brush before installing the stucco.

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 15

March 2003

Energy Design Update®

15

plate through the foam, while the bottom is secured by the soil. The use of adhesive -- either construction adhesive or a trowel-on adhesive -- to adhere the Insul-Guard to the foam is optional. Insul-Guard distributors sell a variety of plastic trim pieces, including inside corners, outside corners, and joiner pieces. Ground Breaker from Nudo Products, like InsulGuard, is a gray, 0.06-inch thick fiberglass panel that comes in 50-foot rolls. Nudo Products sells vinyl trim pieces for use with the product, as well as nylon drive rivets for fastening the material. The rivets are long enough to reach through the foam to the sill plate. The two-piece rivets are inserted into a drilled hole; tapping the rivet pin spreads the rivet's legs. Installation with adhesives is also acceptable.

A Protective Layer Bonded To Foam

As this article was being readied for the printer, EDU learned of a new product, Premium-R Board, consisting of a protective layer bonded to a panel of rigid foam. Each 12 inch by 96 inch panel of Premium R-Board is made from 1 1/2-inch-thick Dow expanded polystyrene adhered to a protective asphalt membrane incorporating a polyester fabric. The protective membrane is coated with a durable paint, and is said to withstand abuse from weed-whackers. The back of the rigid foam is bonded to a peel-and-stick membrane, allowing the Premium RBoard to be adhered to a concrete foundation without fasteners. With a V-groove hot knife, the foam can be formed into a double bevel that hinges to make an outside corner. Premium R-Board is manufactured by Protecto Wrap, and sells for about $28 to $31 per panel. For more information, contact: Barker Steel (an Insul-Guard distributor), P.O. Box 553, Canaan, NH 03741. Tel: (800) 876-5767. Diversified Composites (manufacturer of InsulGuard), 1600 Dolwick Drive, Erlanger, KY 41018. Tel: (859) 282-7300; Web site: www.diversified-com posites.com.

Figure 9. -- Fiberglass or vinyl panels are usually mechanically fastened to the sill plate through the foam insulation, and retained at the base by the soil. This illustration was provided by Nudo Products, manufacturer of Ground Breaker.

Nudo Products (manufacturer of Ground Breaker), 1500 Taylor Avenue, Springfield, IL 62703. Tel: (800) 826-4132 or (217) 528-5636; Fax: (217) 528-8722; Web site: www.nudo.com. Protecto Wrap, 2255 South Delaware Street, Denver, CO 80226. Tel: (800) 759-9727 or (303) 777-3001; Fax: (303) 777-9273; Web site: www.protectowrap.com. Styro Tek, P.O. Box 8098, Madison, WI 53708. Tel: (888) 702-9920; Fax: (888) 702-9921; E-mail: [email protected]; Web site: www.styro.net. U.S.E. Hickson Products, 15 Wallsend Drive, Scarborough, Ontario M1E 3X6, Canada. Tel: (416) 724-2000; Fax: (416) 724-6818; Web site: www.use hickson.com. Wausau Supply (an Insul-Guard distributor), P.O. Box 296, Wausau, WI 54402-0296. Tel: (715) 359-2524. Wisconsin Poured Wall Products (manufacturer of InsulCap), S82w19347 Apollo Drive, Muskego, WI 53150. Tel: (888) 679-7272 or (262) 679-7272; Fax: (262) 679-7223; Web site: www.wisconsinpouredwallproducts.com.

READERS' FORUM

ASTM E119's Time-Temperature Curve

Dear Editor, We read your recent article, "Using Cementitious Coatings to Protect Spray Foam" (EDU, December 2002), with great interest since we are manufacturers of a foamed plastic, expanded polystyrene. We are very familiar with the Chapter 26 requirements of the model codes with regards to thermal barrier protection of foam plastics. I would like to note that your statement, "To be approved as a 15-minute thermal barrier, a material needs to pass the ASTM E119 test," is not accurate. The 2000 IBC Section 2603.4 refers to "... an approved thermal barrier of 0.5 inch (12.7 mm) gypsum wallboard or equivalent thermal barrier that will limit the average temperature rise of the unexposed surface to not more than 250°F (120°C) after 15 minutes of fire exposure, complying with the standard time-temperature curve of ASTM E119." This model code language clearly requires that the testing follow the time-temperature curve of ASTM E119;

www.aspenpublishers.com

EDU 2-04

2/19/03

3:37 PM

Page 16

16

Energy Design Update®

March 2003

similar language is contained in the other model codes. This does not mean that the material is tested according to ASTM E119. ASTM E119 is a test method that is normally used to test assemblies of materials for fire resistance, but includes a time-temperature curve that is often used for other fire testing. Todd Bergstrom Technical Director, AFM Corporation Excelsior, Minnesota

What were the cycle times of the Carrier unit? When a central AC unit is properly sized and installed, it will run longer and wring more water out of the air than a unit that has many short cycles. This potential problem could be as simple as an improperly positioned dip switch on the control board. The article states that, "The failure of the high-end Carrier equipment to keep indoor humidity within an acceptable range surprised the researchers." The equipment is sophisticated enough to keep the occupants comfortable. But without any form of reheat, which would use more energy, it may not be possible to dehumidify without overcooling the space. [Edited for length] Tom Buswell Senior Applications Engineer, Air Handlers Group Carrier Corporation Syracuse, New York

Dehumidification With An Air Conditioner

Dear Editor, The article, "Houston Study Looks at Dehumidification Options" (EDU, January 2003), states that "The [Carrier] equipment was unable to maintain the indoor relative humidity of the Houston test house within a reasonable range." Stand-alone dehumidifiers wring water out of the air on the evaporator side and then reheat the air as it passes over the condenser side. Due to mechanical losses in the stand-alone unit, the space temperature will also increase within the space in which the dehumidifier is located, requiring the main air conditioning unit to run longer and consume more energy. Condensers for residential air conditioning applications are located outdoors to reject heat outside the home, so "free" reheat is not available. The [Houston researchers'] test criterion was to maintain RH below 60% for at least 90% of the time. What the Carrier central air conditioning unit is lacking for further dehumidification control in this installation is the addition of reheat in the form of a small electric duct heater.

Editor's Reply

Thanks for your comments. As noted in the Correction in the February 2003 issue of EDU, no consensus has yet been reached on the percentage of hours that indoor relative humidity may reasonably exceed 60%, and, in the absence of homeowner complaints or mold problems -- neither of which existed in the Houston houses being studied -- many people would agree that the Carrier equipment, which maintained indoor RH below 60% for 81% of the time, did provide reasonable humidity control.

TO

SUBSCRIBE CALL

,

1-800-638-8437

OR ORDER ONLINE AT WWW ASPENPUBLISHERS COM

.

.

Energy Design Update

Distribution Center 7201 McKinney Circle Frederick, MD 21704 www.aspenpublishers.com Forwarding Service Requested

Presorted First Class US Postage

PA I D

Permit No. 4205 Southern, MD

Information

EDU 2-04

16 pages

Find more like this

Report File (DMCA)

Our content is added by our users. We aim to remove reported files within 1 working day. Please use this link to notify us:

Report this file as copyright or inappropriate

125486

You might also be interested in

BETA
national architectural 2009:2009.qxd
UFC 3-120-10 Interior Design, with Change 1
2010DossEnvStewardw_notes.ppt [Compatibility Mode]
untitled
NCCER 09 Catalog interior.indd