http://www.greenhomeguide.com/index.php en office@zeitgeistberkeley.com Copyright 2008 2008-10-03 11:29:00 PDT Copyright 2008office@zeitgeistberkeley.comnoThis is an XML content feed. It is intended to be viewed in a newsreader or syndicated to another site, subject to copyright and fair use. http://www.greenhomeguide.com/index.php/knowhow/entry/1380/ Swiss architect Florian Speier is the founder of Zeitgeist Sustainable Residential Design, a firm with offices in Berkeley and San Francisco. He holds master’s degrees in architecture and construction management and is a LEED Accredited Professional. Question: Is it possible to configure an electric tankless water heater to run a 4–5 baseboard hot-water heating system for a small cottage? I would appreciate any advice or information on how to do this. – Larry Cassis, Brooksville, ME Answer: This is possible; unfortunately, it is very inefficient. Not only is electrical energy too valuable to use for heating, but using it with a hydronic baseboard system adds complexity and distribution losses without any gains over electric baseboard heaters. As I explained in my answer to Brittany Sims of Oregon, electrical energy has about three times the carbon footprint per unit of energy that gas has. So while there are many household tasks, such as lighting, that require electrical energy, heating is more efficiently powered by gas (or in absence of gas, oil—but it is typically less efficient and not as "clean" as gas). My recommendation would therefore be to use a tankless gas heater to run your baseboard heating system. If you do not have gas in your cottage, consider a propane tank, or best of all, install a solar hot-water system with a small electric backup. To build a baseboard hydronic heating system, you will need a pump, a manifold, a control system, and the tankless heater of your choice. If you add solar, you will also need solar collectors and a solar storage tank. There are several companies in the Northeast that will pre-assemble a set of everything you need, making the install easy for you or quick for your contractor. Both Radiantec and Radiant Company offer these packages, but Radiantec will not allow the use of tankless heaters in their system. If it is not possible to use gas and your location is not right for solar—so that you are forced to go the electrical route—the best way to heat your home is to use an electric heat pump. Heat pumps do not "burn" electricity to produce heat; they move heat. They are basically air-conditioners running backwards. For each unit of electrical energy expended, they move about 2.5 units of heat energy into your house. As a result, they would conserve 40–60% of the energy used by a system with an electric tankless water heater or electric baseboards. There are two problems: First, Maine has very low outside air temperatures in winter. Second, there are few air-to-water heat pumps on the U.S. market that tie into a hot-water heating system; you may have to switch to forced-air and a standard air-to-air heat pump. Traditional heat pumps require an outside air temperature of about 30 degrees Fahrenheit, but some Northeastern companies have vastly lowered this barrier in recent years. Others import heat pumps from cold Scandinavia that faces the same problem. You will need to buy from a manufacturer that specializes in your climate, like Save Energy Maine or Hallowell. (Save Energy Maine also sells air-to-water heat pumps that would work with your baseboard heaters.) If these systems end up being too expensive, I would recommend researching oil as your next option. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, 2008-10-03 10:29:00 PDT http://www.greenhomeguide.com/index.php/knowhow/entry/1379/ Swiss architect Florian Speier is the founder of Zeitgeist Sustainable Residential Design, a firm with offices in Berkeley and San Francisco. He holds master’s degrees in architecture and construction management and is a LEED Accredited Professional. Question: My family's home is not a good candidate for solar, and we are good about conserving energy in our daily tasks inside the home. What's the next step to be more energy efficient? – Brittany Sims, Portland, OR Answer: If your house is not a candidate for photovoltaic panels (solar panels that produce electricity), you can still look into other alternative sources of energy. Solar hot water is often feasible where photovoltaic panels are not, and www.findsolar.com rates Portland as a good location with an estimated payback time of about eight years. Of course, this requires you to have a roof that is not shaded by trees or neighboring houses. Some locations can also make use of wind or geothermal energy. Unfortunately Portland is not windy enough, but geothermal heat pumps are successful in Oregon and eligible for tax credits. Whether or not one of these technologies works for you, I commend your desire to make your home more energy efficient. As you know, lowering your usage is often cheaper and easier than producing energy. Improving your house and using the right sources of energy for the tasks at hand can greatly reduce your carbon footprint. Seal your home To reduce the energy usage of your home, you need to increase insulation and stop drafts. Have a professional come out to your house to evaluate your specific condition. If you go to the Energy Star website and click on "home energy audits," you can find a professional in your area or follow the instructions for a do-it-yourself audit. Many homes can benefit from simple improvements. It is often complex and expensive to add insulation to the exterior walls, so start with the attic and crawlspace. Blowing cellulose insulation into the attic is an affordable and highly efficient way to reduce your home's energy consumption. Go for a high R-value here—at least the R-38 recommended for your area by the Department of Energy. Since the temperature difference between inside and outside is greatest in the roof area, improvements here translate into the biggest energy savings. Next, tackle the crawlspace. You can either insulate the floor of the house from underneath with sprayfoam (which may not be the most eco-friendly product but does an exceptional job of insulating and sealing any cracks), or you can cover the crawlspace floor with a vapor barrier to keep the air dry and then limit crawlspace ventilation. The latter option is typically cheaper but less effective. Next on the list are windows. In the Pacific Northwest, the most important factor for replacement windows is a low U-value. Nearly every window sold in the U.S. has a performance sticker from the National Fenestration Rating Council, as I explained in my advice to Jackie from Florida. In northern Oregon, where overheating from the sun is rare, the SHGC value is less important. The U-value, however, directly describes the heat loss to the outside during the cooler months, and lower is better. Look for a number below 0.35. Use the right sources of energy for heating Besides reducing heat losses, it is equally important to look at how you use energy in the house. The most important rule is never to use electricity to generate heat. Electricity is the most valuable and expensive form of energy, because the coal plants that produce much of it have an efficiency of only about 30%. A modern, gas-fired domestic water heater, for example, can achieve efficiencies of over 95%, so using gas to heat water is better for the environment by roughly a factor of three. Have a look at how you produce hot water and heat in your house. If you are already using gas, you might still be able to improve efficiency by sealing and insulating the ductwork or upgrading to newer appliances. An energy auditor can check your current appliances and give you detailed cost/benefit advice. For hot water, you could use a very high efficiency water heater like the Polaris (around $3,000) that gets around 95% efficiency compared to around 70% on a standard Energy Star model, or you could switch to a tankless gas heater from Bosch or Takagi (starting at around $600). The latter are not quite as efficient (around 75%), but they make up for most of that by eliminating the storage losses of a hot-water tank. When choosing a forced-air gas furnace, look for high-efficiency Category IV condensing furnaces that are vastly more efficient than standard models. Most manufacturers offer them now. Radiant-heat floors: combine efficiency and comfort If you want to tackle a bigger project, consider this improvement that our firm is currently installing on a remodel and addition—hydronic radiant floor heat. Radiant floor heat is vastly more comfortable than forced air because the air gets less dry and your feet are never cold. It is also more efficient: the floor radiates heat directly to your body, so you require lower inside air temperatures to feel comfortable. The retrofit is relatively simple. Warm-water lines are stapled under your house from the crawlspace and then insulated. A tankless water heater circulates warm water through these tubes. In a so-called "open system" you turn a valve in summer and let all the cold water you use in the house run through these tubes first, giving you free cooling when the weather is hot. The best part of all is the relatively low cost—the pre-assembled system for our 3,000-sq.-ft. project costs only about $6,000, shipped directly from the manufacturer. If you want a solar hot-water tie-in instead of using a water heater, that will cost around $5,000 extra. Some homeowners decide to install these themselves, or you can work with a local contractor. Finally, make sure all electrical appliances are efficient and Energy Star rated, especially your fridge. And, of course, those compact fluorescent lightbulbs save 75% of the energy needed for lighting the home. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, {category_name backspace="1"}, 2008-10-03 10:15:00 PDT http://www.greenhomeguide.com/index.php/knowhow/entry/1378/ Swiss architect Florian Speier is the founder of Zeitgeist Sustainable Residential Design, a firm with offices in Berkeley and San Francisco. He holds master’s degrees in architecture and construction management and is a LEED Accredited Professional. Question: I want to help get my mom's house "off the grid." She lives in a rural area where wind and solar power are feasible energy alternatives. Where do I start? – Jackie Mellen, Chipley, FL Answer: There are two main things we need to discuss for your project: Do you really want to be "off the grid" — as in disconnected from it? It is usually more economical and more environmentally friendly to stay connected, even if you produce all your own energy. Once you have made that decision, we can look into the different ways of producing your own energy and reducing your usage. The grid and net metering The biggest problem of getting off the grid is that the alternative energy sources we have—wind and solar, in your case—don't produce the amount of energy you need at the moment you need it. So going off the grid requires you to store energy, and that means batteries. Unfortunately, batteries are very expensive, have limited capacity, and contain toxic substances. For houses that are (or can be) connected to the grid, it is usually preferable to use a technology called net metering. Basically, you use the grid as a giant battery. You feed power into it when you produce more than you need, and take power from it when you need more than you produce. No power gets wasted, because the electricity companies lower the output of their coal-burning power plants by the amount of electricity you put into the grid. You avoid the expense of batteries, and in most states you get paid very well for feeding the grid. Selecting a source of alternative energy In nearly all areas, the most feasible alternative energy system is solar thermal for domestic hot water (and for heating if you can use a hydronic hot-water heating system). I recommend you start with solar hot water because this is a very simple technology that is easy to add to most homes at a moderate cost. Once you have solar hot water in place, your options for alternative sources of energy are wind and solar electric. In deciding between the two of them, the key factors are your average wind speed and solar radiation. As a rule of thumb, wind energy becomes competitive for properties with average wind speeds of 10 mph or more. The website of the American Wind Energy Association is a starting point to research this. When I searched for your location, the closest data I found was for Tallahassee, Florida, where unfortunately the reported average wind speed of 6.2 mph is too low. Unless your house is located on a ridge, or topography channels winds into your immediate area, I doubt wind will be a feasible energy source. Solar, on the other hand, is quite efficient in Florida, so the first step would be to contact a provider and have them prepare a proposal that clearly shows the amount of energy produced in a year and the cost. You can find providers at www.findsolar.com (the website also has a calculator to help you estimate system size and cost). The next step is to look into tax rebates and government incentives available in your area. You will get a federal income tax rebate for 30 percent of the system cost, and the state of Florida will contribute another $4 per installed Watt. A solar hot-water system would also qualify you for a $500 credit. You can find more information on this topic at the Florida Renewable Energy Association's website. Reducing your usage is easier than producing power While it feels great to produce your own power sustainably, it is just as good for the environment to reduce your consumption. Many residences can cut their power needs in half with relatively minor measures. In Florida, this means cutting the load on the air-conditioning system by allowing less heat to enter the house. Obviously, a well insulated and sealed house with high-quality windows is ideal, but everyone has to work with what is already there. Attic insulation can often be upgraded easily: Energy Star recommends a minimum of R-30 for attic insulation in your area and the Department of Energy recommends R-38 to R-49. The additional cost of going to a higher R-value is often very small, so I would follow the higher recommendations. If you replace any windows, study the label on the product by the National Fenestration Rating Council. There are two main values, the U-Factor and the Solar Heat Gain Coefficient. For both values, lower is better, but they measure very different things. U-Factor describes how much heat moves through the window due to the air temperature difference between inside and outside. That is important, but in Florida the Solar Heat Gain Coefficient (SHGC) is much more important, especially on south and west facades. SHGC describes how much of the energy in a sun ray that hits the window will enter your house. A value of 0.32 means that 32 percent of the ray's energy ends up as heat indoors that your air conditioner has to move back outdoors. Energy Star recommends an SHGC of 0.35 or less for your area. Another way to reduce heat gain is to shade windows to the south and east externally. Parapets can often be added on the south facade. On the west side of the house they are inefficient, as the low-standing evening sun shines underneath them—opt for external shutters instead. These are many times more efficient than shades or shutters on the inside of the window. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, {category_name backspace="1"}, 2008-10-03 09:38:00 PDT http://www.greenhomeguide.com/index.php/knowhow/entry/1377/ Martine Paquin is a San Francisco–based sustainable design consultant with over 10 years of experience focusing on modern and green concepts. She is a LEED Accredited Professional, a member of the USGBC, and an AIA associate. Question: With our baby due soon, we are trying to determine the safest way to get the nursery ready. The carpet in the room is ripped up and destroyed from our pets. If we use a green sealer to refinish the hardwood floor underneath, is this better than installing new carpet, even if the carpet is low- or no-VOC? – Anna Hilton, Philadelphia, PA Answer: I recommend you refinish your hardwood floor and add a natural-fiber area rug. Hardwood is long-lasting and easy to clean, and the rug will reduce noise. If you can, vacate your home while a professional removes the old carpet and refinishes your hardwood. Refinishing one room can take three to four days, plus a few days to dry completely. Take advantage of the time off while preparing the nest. The person sanding and refinishing your floor should refer to this Ask A Pro article for detailed advice about safely refinishing the floor. Seal all interior openings (including vents and the air return) to isolate the room from the rest of the house and protect you and your belongings. A low-VOC coating product from Safecoat or Basic Coatings will protect your newly sanded floor. You can learn more about floor refinishing products by referring to GreenHomeGuide's "Buyer’s Guide to Clear Finishes" and "Buyer’s Guide to Stains." A natural-fiber area rug—for example, a wool rug with jute backing—would be safe for a nursery. The rug can be sent to a green cleaning service as needed, especially when your baby starts crawling. If you choose to recarpet the space, tack down the carpet instead of using adhesives, and select a natural-fiber carpet and pad. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, {category_name backspace="1"}, {category_name backspace="1"}, 2008-09-11 11:53:00 PDT http://www.greenhomeguide.com/index.php/knowhow/entry/1375/ Martine Paquin is a San Francisco–based sustainable design consultant with over 10 years of experience focusing on modern and green concepts. She is a LEED Accredited Professional, a member of the USGBC, and an AIA associate. Question: If we use engineered hardwood flooring, we know that we should look for formaldehyde-free adhesives. If we choose solid hardwood instead, is it true that the flooring would be nailed or screwed in place, and that there would therefore be no formaldehyde issue? – Herbert Lichtman, Chicago, IL Answer: The answer depends on your subfloor material and the product you’re installing. If you have a plywood subfloor, solid hardwood flooring is typically fastened by nailing or stapling. (It’s less common nowadays to use screws.) A small number of flooring products are both nailed and glued to a plywood subfloor. It's best for indoor air quality to avoid using adhesive, but if you need to, you can use an option such as EcoTimber Healthy Bond, a resin-based product that has only 7 g/L of VOC. If possible, you can go the extra distance and choose a formaldehyde-free 3/4" plywood substrate. If your subfloor is concrete, you may want to use a glueless engineered hardwood system instead of solid hardwood. These systems are fastened from the baseboards—a technique called "floating"—and no nails or adhesives are necessary. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, {category_name backspace="1"}, 2008-09-11 09:27:01 PDT http://www.greenhomeguide.com/index.php/knowhow/entry/1376/ Martine Paquin is a San Francisco–based sustainable design consultant with over 10 years of experience focusing on modern and green concepts. She is a LEED Accredited Professional, a member of the USGBC, and an AIA associate. Question: We have a wood (glue-down) floor that needs to be replaced, and we are considering stamped concrete, bamboo, or just going back to wood. We are looking at ways to make the house green. Also, we have a pool, teenage boys, and two dogs. What would be the best solution? – Nancy Meisch, North Richland Hills, TX Answer: Installing a low-maintenance product that will withstand abuse is key. Many options are available for wood and concrete. Select hardwood flooring or a concrete tile that will patina with elegance. FSC-certified hardwoods like oak, pecan, maple, and mesquite would withstand your home traffic. You can refer to a Janka hardness chart for more selections; hardness of a minimum 1300 Jankas would be suitable for you. Another alternative is reclaimed hardwood—look for wood that's been certified by the SmartWood program. Bamboo is a rapidly renewable material as hard as oak. Stranded or woven bamboo products are even harder because they are manufactured with resin. These products are 2400–3000 Jankas (really high). Teragren has a great product that contains a negligible amount of urea-formaldehyde. Concrete tile products are also a good choice. Choose a product that has integral color throughout the body of the tile so if it chips because of abuse, the damage won’t be obvious. Many concrete tile products are made in the U.S. For example, Smith-Laredo has tiles in a variety of sizes, in earth colors suitable to both modern and rustic design. An even greener product is Syndecrete, a precast lightweight concrete tile containing fly ash and recycled waste from carpet manufacturing. For more information: Read GreenHomeGuide’s Ask A Pro article "Can you recommend healthy flooring for a home with kids and pets?" for more information about durable, low-maintenance flooring. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, {category_name backspace="1"}, 2008-09-11 09:04:01 PDT http://www.greenhomeguide.com/index.php/knowhow/entry/1373/ Paul Rosen is President of NorthBay Energy Services, Inc. He is a LEED Accredited Professional, licensed general contractor, and building performance consultant to architects, builders, and homeowners. Paul and his family live in a LEED-certified zero energy home they built in Sebastopol, California. He holds a BSE from the University of Michigan in Industrial Engineering and Systems Design. Question: In the near future, we are planning to renovate, remodel, and expand our older home. At that time I would like to install PV cells to power our home. I was hoping to tie onto the grid and sell back any extra kilowatts we do not use, but this being a relatively small area, I may be the first to do it. I don't think I am searching in the right places or asking the right people. Can you help? – Wendie Hall, Albertville, AL Answer: Before buying a solar system, the best practice is to "reduce, then produce" as I advised in a separate Ask A Pro article here. The relatively inexpensive recommendations in a Home Performance Audit will increase the energy efficiency, comfort, and health of your home, enabling you to invest in a more modest and effective photovoltaic system. After that, take a look at your new reduced utility bills to help decide the size of the PV system you really need. Most homes will do well to produce half to two thirds of their average electric consumption. This assumes that you have a utility grid to which you can remain connected to make up the difference. Check with your local utility company to see what programs are available. Many utility companies allow you to credit the excess electricity you produce during sunny days toward the electricity you need at night and days with insufficient sun. This is commonly known as net metering. The Database of State Incentives for Renewables and Efficiency (DSIRE) provides a list of net metering rules by state. In general, there are more incentives for grid-tied systems than for off-grid systems, but a grid-tied system means you’ll be without electricity during a blackout or power failure. The only way to be completely independent of the utility grid is to have battery back-up, but this is expensive and hard to justify unless you live in a remote location or really must have continuous power. For more information: The U.S. Department of Energy also has details on its website about net metering. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, 2008-07-16 11:26:01 PDT http://www.greenhomeguide.com/index.php/knowhow/entry/1372/ Paul Rosen is President of NorthBay Energy Services, Inc. He is a LEED Accredited Professional, licensed general contractor, and building performance consultant to architects, builders, and homeowners. Paul and his family live in a LEED-certified zero energy home they built in Sebastopol, California. He holds a BSE from the University of Michigan in Industrial Engineering and Systems Design. Question: I am interested in a solar photovoltaic system. What do you recommend for an old house? – Exton Quinn, Santa Monica, CA Answer: I recommend you first "reduce, then produce" energy for your home. Older homes are generally inefficient, often uncomfortable, and even unhealthy. By improving your home's performance, you can address all three of these issues at the same time, at a lower cost per dollar of energy saved than the cost of producing electricity with a photovoltaic system. (I provide advice on sizing a solar PV system in a separate Ask A Pro article here.) To illustrate the advantage of a "reduce, then produce" approach, here's an overview of a home performance project my firm completed last year. The whole project cost approximately $15,000 and the payback should be less than 10 years. By comparison, that same $15,000 could have paid for a 1.7 kW PV system, which would produce about 3,000 kilowatts of electricity worth maybe $750 annually in savings at our high electric rates. That means breaking even on the PV system would take 20 years—twice as long as the 10-year payback on improving the home's performance! For this project we worked on a beautiful 2,100-square-foot 1908 craftsman house in the Bay Area that had high utility bills, drafts and uneven heating on cold winter days, uncomfortably hot bedrooms during the summer, and a stuffy damp smell after a big storm during the rainy season. A Home Performance Audit revealed the following issues: A Blower Door test determined the home had a "leakage" rate of 1.2 air changes per hour. The recommended ACH, according to ASHRAE (American Society of Heating, Refrigeration, and Air Conditioning Engineers) is .35 ACH. In other words, the home was almost four times "leakier" than desired. The total of little and big leaks equaled having a two-foot square hole open to the outside. A Duct Blaster test of the natural-gas, forced-air heating system indicated the ducts leaked over 45% of their output. In other words, almost half the heat output never made it into the conditioned living space. Because it was built when energy was abundant, the house had no insulation in the walls; it had a poorly insulated attic and asbestos insulation on the forced-air ducts. The lighting was primarily incandescent lamps and the household appliances were an average of 14 years old. We took the following steps to improve the home's performance. We reduced leakage by "air sealing" penetrations in the attic and floor, which took care of half the issue. Weather-stripping the windows and doors finished the job. We installed a new duct system, which solved the lost energy and pressure issues, and the uneven heating, by supplying the correct air flow volume and velocity to each of the rooms. The existing furnace was only eight years old and did not need to be replaced. Cellulose insulation (made from 100% recycled material) was blown into the attic to a level of R 38 (exceeding the current R 30 code requirement). In this Mediterranean climate, insulating the walls would have only increased the energy efficiency an additional 5% and was not cost effective or necessary. The air sealing of the attic and floor stopped most of the heat loss through the walls by preventing the flow of air currents that "suck" the heat out via conduction. The crawlspace floor and foundation walls were "vapor proofed" with a special fabric, and the vents were closed off. A mechanical vent fan brings in fresh air when needed. This not only stopped the musty damp smells, but also made the floors warmer and improved efficiency. Most of the lightbulbs were changed to CFLs (compact fluorescent lamps); a new Energy Star refrigerator was installed; and the big-screen TV and entertainment center were put on a master switch that can be turned off when the area is not being used, eliminating the significant standby power loss. The outcome of this project was: The natural-gas consumption for heating was reduced by 60%. The electric bill was cut in half. The home is now very comfortable, and the space evenly conditioned year-round. There are maybe five or six hot days when it would be nice to have air conditioning, but it's not really necessary. The air quality is significantly improved and all unpleasant smells have been eliminated. The whole project cost approximately $15,000 and the simple payback should be less than 10 years. Breaking even on a new PV system would take 20 years—twice as long! Remember the best first step before adding a solar system is "reduce, then produce!" For more information: I provide advice on sizing a solar PV system in a separate Ask A Pro article here, and architect Cynthia Phakos has also given good advice on converting a home to solar energy. Two great sites to learn more about home performance are the EPA's Energy Star website and, in California, the utility-funded Green Home Energy Upgrade program provided by California Building Performance Contractors Association. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, {category_name backspace="1"}, 2008-07-16 10:15:01 PDT http://www.greenhomeguide.com/index.php/knowhow/entry/1371/ Paul Rosen is President of NorthBay Energy Services, Inc. He is a LEED Accredited Professional, licensed general contractor, and building performance consultant to architects, builders, and homeowners. Paul and his family live in a LEED-certified zero energy home they built in Sebastopol, California. He holds a BSE from the University of Michigan in Industrial Engineering and Systems Design. Question: I recently heard about solar hot-water heaters for the first time. Apparently they are more affordable than a traditional photovoltaic panel system for electricity. Can you give me more details about what these systems are, how they work, and how much they cost? Finally, is there anyone in my area doing installations? – Betsy Humes, Brooklyn, NY Answer: Solar water heating has been around since the Mayans used stones heated by the sun to warm their sacred baths. A well-designed solar thermal water-heating system can operate efficiently practically anywhere in the United States. The moderate to warm climates of the southern and western parts of the U.S. are well suited to the traditional flat-plate collector. For the parts of Europe and the U.S. with colder climates, the evacuated tube hot-water solar collector is quite efficient. A solar thermal water heater is 60–70% efficient in collecting the sun’s energy, whereas the average photovoltaic system is in the neighborhood of 14–20% efficient in converting the sun’s energy. As a result, heating water with PV usually does not make economic sense. Additionally, a solar water heater can operate efficiently even where there is some shading, while a PV system's performance is significantly reduced when partially shaded by adjacent buildings or trees. Many homes that won’t support an efficient PV system can produce a good amount of hot water with a thermal system. For a family of four, a solar water heater supplying 50–70% of the domestic hot water should cost $6,000–$8,000. A federal tax credit can reduce the cost by $2,000, and some states and municipalities offer additional incentives. The Database of State Incentives for Renewables & Efficiency (DSIRE) has details of incentives for your home state of New York, and all other states, too. The payback can be as short as five or six years. To find someone doing solar installations in your area, check GreenHomeGuide’s directory of green pros in San Francisco, Los Angeles, and New York. For more information: The Department of Energy publishes an online Consumer's Guide to Energy Efficiency and Renewable Energy that includes a good explanation of solar water heaters. YouTube has a video of a solar hot water installation. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, 2008-07-14 17:08:00 PDT http://www.greenhomeguide.com/index.php/knowhow/entry/1370/ Kirsten Flynn is an interior designer and owns the firm Sustainable Home, which does residential projects on the San Francisco Peninsula. She has a design degree from Syracuse University and was the first recipient of the Green Design Certificate from Cañada College. She is also a Certified Green Building Professional and a member of the U.S. Green Building Council. Question: I'd like to know more about plant-fiber floorings such as sisal, jute, coir, and sea grass. What are the resources used to manufacture these flooring products? And what happens to these materials when they must be thrown away? – Christine Wong, Ithaca, NY Answer: Your question makes a great case study for a technique I use with my clients in evaluating materials choices. I call it the "gut LCA" (Life Cycle Analysis). One reason homeowners sometimes steer away from green materials is that the evaluation process is complex. I use three simple questions to help people decide whether they want to use a material. Let's use these three questions to evaluate woven plant-fiber floorings. 1. Do you like what it did while it was being made? Natural-fiber floorings like sisal and sea grass—as well as paper cord and water hyacinth—are made of rapidly renewable natural materials. These materials are processed and woven in very low-tech factories using local labor. Most production is in Asia, which means that the product is shipped a long distance before you purchase it. This adds to the product's carbon footprint. It might be worth asking the wholesale source of the product what they know about the labor practices of the manufacturer. It is hard to know if a living wage was paid when a product was made in a distant country. Woven oriental carpets have a RugMark certification that ensures no children were employed as weavers. Unfortunately, there is no such certification for natural-fiber flooring products. The more consumers ask about fair labor practices, the sooner we will have a similar evaluation tool for these products. My conclusion? Rapidly renewable and natural, which is good, but not locally made, which is less good. 2. Do you like what it does while you have it? Of course you should love the way your flooring looks. But will the plant-fiber carpeting last well in your setting? Most plant-fiber flooring is fairly sensitive to moisture discoloration, so you should make sure you place it in an area where you can protect it from spills. Sea grass, because it is grown in saltwater marshes, is the most stain-resistant option. Because these are natural products, as opposed to man-made fibers, they typically do not trigger reactions in chemically sensitive individuals. Be sure to ask if the backing is also natural; rubber-tree latex is often used as a backing, but sometimes the backings are man-made. You should also keep in mind that any wall-to-wall installation of soft flooring has the potential to become a dust sink. Because of the texture, and because it can't be wet-mopped to remove dust, carpeting can aggravate allergies. Pollen and other particles can get trapped in the weave of the carpet and can be impossible to completely vacuum out. If a client wants carpet, I often ask if we can limit it to areas that are more than 20 steps from any door to the house. This allows residents to walk off some of the dirt they track in before they reach the soft floor. My conclusion? The primary consideration here is visual. It is important that you love the look of anything you will allow into your home. One concern in this phase is whether you can protect these materials from spills and from harboring allergens. 3. Do you like where this product goes when you are done with it? You asked about disposal, and that shows you're already thinking about the life cycle of the products you buy. My favorite materials are those that can biodegrade or be recycled endlessly. An example of the latter is anything made of steel, and an example of the former is plant-fiber flooring. Conventional carpet disposal puts a strain on landfills. Nylon or polyester fibers do not biodegrade, and according to one statistic I heard, 800 million square yards of carpet are thrown away every year! Even if a material can biodegrade, it won't necessarily do so in a landfill. Most landfills are dry and airless, and microbes need air and water to break down materials. If your municipality has a composting program for yard waste, you could contact them to see if they will accept your used natural-fiber flooring. If they won't, try contacting a local recycler of construction and demolition waste. These providers often have a system for wood scraps that are too small for reuse—your natural-fiber carpet, also being a plant product, might be accepted for recycling here. The wood is usually chipped and used as a ground cover, composted, or used to cover trash at the dump. My conclusion? Plant-fiber flooring is one of the few fully biodegradable home furnishing products; I like that! But you might have to make an effort to make sure it actually gets composted. It's useful to know what your goals are in choosing a material. Do you want to reduce the amount of waste you produce? Do you want to lower your carbon footprint and build the local economy by buying local products? Do you want to choose products that are allergen and chemical free? If one of these considerations is primary, it will affect how you look at the three product-evaluation questions. Good luck choosing! For more information: Check out GreenHomeGuide's Flooring Know-How section for buyer's guides, case studies, and product reviews. GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S. {category_name backspace="1"}, {category_name backspace="1"}, {category_name backspace="1"}, 2008-06-19 21:22:00 PDT nonadult