Tag Archives: energy efficient

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energy efficient hot water system


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Comparing energy-efficient hot water heaters probably isn’t on your green homebuilding to-do list. But, wait a minute! Water heating is the second biggest expense in your home, and the average family uses 64 gallons of water a day and spends $400 to $600 a year on hot showers and clean dishes and laundry. It’s time to check out the most energy-savvy options available.

Size up the situation
The first thing to do is to figure out your family’s peak-hour hot water demand, and then discuss options with your general contractor. If your water utility offers a free online service to manage your monthly water usage, sign up and use the data to calculate the size of tank you need.

Research your options
Contractors and plumbers understand conventional storage hot water systems, but some of them are not familiar with more sustainable options like tankless (on-demand) or solar hot water heaters. Don’t let them talk you out of using technologies they don’t understand. Be proactive—do your own research and meet with reputable installationcontractors who can help you calculate the right size system for your home and know how to integrate it with the plumbing.

Shop for heating systems
There are five types of water heaters available: conventional storage, tankless (on-demand), heat pump, tankless coil and indirect, and solar.

Conventional storage water heaters
, which run on electricity, natural gas, propane or fuel oil, are relatively inexpensive to install and run. But, they waste energy keeping gallons of water heated 24/7 and lose heat due to lack of tank insulation. New, high-efficiency gas-powered models and gas condensing water heaters (that use heat generated from combustion gases to help heat the water) are more energy-efficient options.

Tankless (on-demand) water heaters, which are powered by natural gas, electricity or propane, heat your water without using a storage tank and are eight to 34 percent more energy efficient than storage heaters. However, they have limited flow rates, which can mean cooler water during simultaneous multiple uses or when there are long distances between the heater and your showerhead. Installing two tankless systems can solve the problem, though the energy savings might not offset purchase and installation costs.

Heat pump water heaters use electricity, natural gas or geothermal energy (heat from the Earth) to heat water. These units are two to three times more energy efficient than a conventional storage water heater. However, they work best in areas where the temperature is between 40 and 90°F all year, and they exhaust cold air. Consult a knowledgeable professional for more details.

Tankless coil and indirect water heaters use your home’s space heating system to heat water and run on electricity, natural gas, fuel oil or propane. Advantages include lower installation and maintenance costs, but they are not a good choice for warmer climates. Talk to an installation contractor for more information.

Solar water heaters, which heat water using the sun’s energy, are fifty percent more efficient than electric or gas water heaters. But, the initial investment is higher, and some people install a backup system (or budget water use) during cloudy days and peak-demand times. Have a solar hot water professional visit your site to see how much sun it receives, discuss system options, and tell you about available rebates and incentives.

Fuel Source, Energy Star
Today’s water heating systems are powered by electricity, natural gas, propane, fuel oil, geothermal or solar depending on the type of heater. Your property location determines which fuel sources are available to you.
After comparing energy-efficient hot water heaters, costs, life expectancy, pros and cons and fuel sources (check out Energy.gov’s helpful infographic), you can decide which is the best choice for your family. As you consider appliances, look for the Energy-Star label — denoting high-efficiency — on gas storage water heaters, gas condensing water heaters, whole-home gas tankless water heaters, heat pump water heaters and solar water heaters. Choosing the right hot water heater for your needs can not only save energy, water, and money, but it can help you enjoy a hot shower with a clean conscience knowing that you are putting less stress on the environment.

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solar panels

Solar Panels Made Simple

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Written by Joyanna Laughlin for Time to Build a Houseplans Blog

Properly oriented solar panels can make a house or cabin energy-independent.

Are you thinking about installing solar panels as part of living a greener lifestyle? Here’s what you need to know from homeowners and experts who have done the homework for you.

Solar panels or photovoltaic? It’s the same thing. What most people call solar panels are the modular, silicon-based, flat-plate photovoltaic (PV) panels that turn sunlight into electricity, says Ben Uyeda, designer, co-founder of ZeroEnergy Design and FreeGreen.com, and director of HomeMade Modern. A solar electric (a.k.a. photovoltaic) system includes a group of PV panels, inverters [pieces of equipment that convert direct-current (DC) electricity generated by a group of PV panels into alternating-current (AC) electricity that can run your appliances], a mounting system and other equipment.

Additional types of solar energy systems include flexible solar photovoltaic films (used on metal roofing systems, boats, recreational vehicles, etc.) and solar thermal systems, which produce hot water to supplement your home’s water heating system, says Alan Spector, architect and owner of Lafayette, New Jersey-based Spector Associates Architects.

Understand your energy usage
In order to figure out how much energy you need to power your home using the sun, you need to know how much energy you use. This means understanding how much energy it takes to do things like heating your home or making a cup of coffee. According to Estimating Home Appliance and Energy Use on the U.S. Department of Energy’s Energy.Gov website, it takes between 1,800 and 5,000 watts to dry a load of clothes, between 1,200 and 1,875 watts to dry your hair, and 900 to 1,200 watts to brew a pot of coffee. Energy consumption has to do with personal habits, says Kirpal Johnson, an energy consultant for San Mateo, California-based solar installation company SolarCity. Leaving doors open and lights on or running the furnace or air conditioning a lot increases energy consumption. Performing a home energy audit can help you to find out what your actual numbers are. There are tools online to help you do it yourself, and there are also private companies, as well as some public utilities, that will do it for you.

Shop around
Once you’ve decided to include a PV system in the design of your new home, Uyeda recommends having your general contractor get bids from subcontractors, and Spector adds that it’s a good idea to compare three bids from qualified installers. Research the installers to make sure that they are legitimate companies, and to understand the contract you are signing. “Educate yourself on the company, and inform yourself about the contract,” advises SolarCity’s Johnson. “Homeowners need to be involved at an active level and engaged with the process and the numbers,” Johnson says.

Check the numbers
The installer you select to design your PV system should provide you with an exact calculation of the amount of energy your system will produce, Spector says. You can verify the numbers the installer gives you by using websites such as the National Renewable Energy Laboratory’s PV Watts Calculator.

Buy brand name equipment
Most PV panels have similar conversion efficiencies (the rate at which the panels convert sunlight into electricity). Make sure that your PV panels and inverters are established brand products with good warranties, says Spector. Uyeda recommends telling your general contractor and installer what you are looking for (including good warranties on the equipment) and letting your general contractor and installer pick the brand. Some major solar panel brands include SunPower, Kyocera, Sharp, Yingli, LG and Canadian Solar. And SolarCity recently purchased Silevo, a manufacturer of high-efficiency solar modules, which means they are getting into manufacturing solar panels, a business that is currently dominated by Chinese companies. And SMA, Outback and Fronius are established brands of inverters.

Solar works in cold climates
Solar systems are not just for people in very sunny places. Solar also makes sense in cooler, northern climates. “The important thing is proper orientation to the sun and the amount of sunlight the location receives,” Spector says. “Germany is the world leader in solar, PV and it has only moderate sunlight.” Spector owns a 3,163-sq.-ft., home in New Jersey with a 5-kw PV system that provides 65 percent of the home’s electricity needs and powers Spector’s electric car, a Nissan Leaf.Uyeda designed his own 1,200 sq.-ft energy-efficient home, which is currently under construction in Boston, and he is having a 4-KW PV grid-tied system installed to provide a portion of the home’s electricity needs and to power his Nissan Leaf — the exact amount depends on how much he drives the car. “If you are building a new home in a cold climate,” he says, “solar shouldn’t be the first thing you think about. Consider the building envelope first (orientation, insulation, and energy efficiency). Don’t spend a lot of money on solar to heat an inefficient home.”

Financing options
There are several options, including buying your PV system up front (which might cost $20,000 or $30,000, says Johnson), rolling the cost of the system into your mortgage like Uyeda is doing with his home, or leasing your system from a large installer like SolarCity. Uyeda prefers packaging the cost of his PV system into his mortgage because the money he would have spent on gas is now going to increase the value of his home, which is a tangible asset. The main benefit of leasing is that you can get a PV system on your home without paying any money up front, Johnson says. Solar City installs the system, insures it, monitors its performance, and handles repairs and maintenance. You sign a 20-year contract with SolarCity, and they take a percentage of your energy savings over the life of your contract. Whichever financing option you choose, going solar can be a simple process and you can soon be on your way to lower energy bills and contributing toward a cleaner environment.

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essentials for building green

12 Essentials for Building Green

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Written by Joyanna Laughlin for Time to Build a Houseplans Blog

The goal for this vacation house in Rhode Island — by Zero Energy Design — was to minimize energy use.

At first, building a new energy-efficient home is all about imagining the best of what’s possible—the hottest design, the latest green technology, and the coolest energy-efficient products. Then, reality bumps into your dreams. Maybe it’s your budget or even the limitations of your building site. To help take the bumps out of the building process, Time To Build asked five architects and designers who specialize in sustainable development and green design to share their hard earned experience on what you need to know before breaking ground.Know your budget
According to Ben Uyeda, designer, co-founder of ZeroEnergy Design  and FreeGreen, and director of HomeMade Modern, the biggest mistake people make is that they design their house twice. “First, they get it costed out with what they want; then, they get it redesigned with what they can afford,” he says. The key is to coordinate the most cost-optimal approach to reducing your home’s footprint while adding environmental benefits.Look at the whole picture
Use a holistic approach in your design process, says Jennifer R Young, AIA, LEED AP BD+C at the firm of Lake Flato Architects in San Antonio, Texas. Consider overall comfort, connection to the outdoors, sustainable material sourcing, healthy products and the highest indoor air quality.

Review project goals
To Nancy Malone, AIA, LEED Fellow, and a principal Siegel & Strain Architects in Emeryville, California, it’s critical to set key project goals, at the beginning of the process, and revisit them frequently. “Review your goals at key milestones, and use them to make design decisions, especially value-engineering decisions,” Malone says.

Understand your climate
Perform a climate analysis early in the design process to help understand the particular weather patterns and sun angles of your site, Young advises. “The more you understand about your site, the more passive strategies you can employ, which gives you a head start on creating a comfortable, energy efficient home,” she explains.

Orient and Insulate
The tried and true methods for building an energy-efficient home are still the best, says Paul Warner, licensed architect, general contractor, and principal of San Francisco-based Sagemodern Inc. These include orienting your house and placing windows to maximize solar gain when you want it and minimize it when you don’t, designing the correct overhangs and other window shading, using the right amount of insulation, and air sealing. Young adds, “If possible, orient your home on an east-west axis, which allows you to minimize the amount of lower/harder-to-shade sun from the east and west, to maximize southern exposure in your heating season (if you have one), and to gain the soft northern light year round.”

There is no green bullet
There is no one-size-fits-all solution to energy efficiency. For example, while the idea that you get more value for every dollar spent on insulation is generally true, it depends on the difference between the temperature inside and outside of your home, Uyeda says. What has a huge impact in Austin, Texas, may not work as well in Santa Barbara, California.

Size matters
Smaller houses are inherently more resource efficient than larger ones, Warner says. As Jonathan Feldman, AIA, principal of San Francisco-based Feldman Architecture, points out, larger homes not only consume much more energy, but they require more materials to build, which also have large amounts of embodied energy. Young agrees. “It’s always tempting to want more space,” she says. “But, think about what you need day to day, and allow one space to have multiple programs.”Warner sums it up: “A compact floor plan with good orientation and good insulation not only saves energy in the long run, but it should allow you to install smaller mechanical equipment.” Make sure your mechanical contractor properly sizes your HVAC system so that it runs at peak efficiency, and you’re not paying for excess capacity.

Don’t believe the hype
You don’t have to buy into a lot of complicated systems or fancy gadgets to achieve energy efficiency. “Keep things simple, and purchase systems and appliances that make your life simpler and are easy to program without costly maintenance,” Young says. Malone agrees. “Our culture has solved many of our design challenges with technological solutions,” she says. “Although many of these solutions offer benefits, we can design energy efficient homes with a set of fairly low-tech engineering principles.”

Ask how they know
Ask your design team what stands behind their recommendations. Uyeda suggests asking if they use modeling software and cost-benefit analyses to determine what’s right for your home. Malone agrees. Energy models can analyze predicted energy performance in a given design, and also model variations such as different wall assemblies, windows and mechanical systems, to identify which elements will be the most—or least—worth investing in.

Know your priorities
Understanding what green means to you, and communicating with your design team is crucial. “If you are looking for a return on your investment, then you should aim to balance your electric load and onsite energy generation (solar, wind, geothermal, fuel cell) with a goal of supplying at least enough energy so that you don’t exceed your utility company’s lowest tier pricing structure,” Feldman explains. “If you want to be net-zero, then that leads to different design strategies.”

Pay attention to your lifestyle
Be honest about your energy usage and habits. If you forget to turn off the lights, a lighting control system, occupancy sensors, or an app on your phone that can turn off your lights can help save energy. Or if you have other specific needs, like cooling a large wine collection or running electronic sound and video equipment, tell your design team.

Solar Strategies
If you’re considering adding expensive features like a solar system to your home, one way to save money is to package the cost with your mortgage. Uyeda put solar panels on the roof of his house, uses them to charge his electric car among other things, and financed the cost in his mortgage.

The bottom line: Understand your priorities and lifestyle, know that there’s no one-size-fits-all way to achieve energy efficiency, and be prepared to communicate your priorities to your design/build team are keys to help you make your dreams of a new green home become a reality.

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Common Sense Energy Efficiency

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Article written by Joyanna Laughlin for Time to Build Blog

Don’t Sweat The Small Stuff by Joyanna Laughlin

From air sealing to solar panels, green building experts David Johnston and Marc Richmond offer tips on saving time, energy and money when building your energy-efficient home.

Seal It Up Right

Air sealing is as important to your home’s energy efficiency as selecting the right R-value insulation, says David Johnston, president of the Boulder, Colorado-based green building firm What’s Working. “Air seal everywhere that building components come together and/or where something penetrates the walls, such as doors, windows and hose bibs,” Johnston says.

Right-Size Your HVAC
Most heating, ventilation and air conditioning (HVAC) systems are not professionally designed or engineered specifically for your home, according to Marc Richmond, manager of the Austin, Texas-based green building firm Practica Consulting. HVAC systems tend to be oversized by 50 to 70 percent, and the forced air ducts tend to leak at a rate of between 20 and 30 percent. To avoid this, ask your HVAC contractor to use Air Conditioning Contractors of America (ACCA) Manuals J, D, S and T to size and install the system. In addition, make sure that your contractor tests the ductwork and ensures that its leak rate is less than six percent.

Use Water Sense
“Water shortages are going to be a much bigger problem for many areas in the United States than climate change,” Johnston says. “At any given time, one third of the country is suffering drought.” Richmond recommends: Purchasing only WaterSense-certified showerheads, faucets, toilets, washing machines, dishwashers, and irrigation controllers. (WaterSense is a partnership program of the U.S. Environmental Protection Agency.) Buying toilets that score higher than 500 on the MaP (maximum performance) scale. (MaP is a voluntary North American testing program that rates toilet efficiency and flush performance).
Installing a drip irrigation system that includes a smart controller (featuring a rain or soil moisture sensor to stop irrigation when the soil is wet), and using micro-spray heads for landscape beds and multi-stream rotors for turf areas. Planting low-water-use plants and turf, reducing turf areas, and hydrozoning landscaping (saving water by grouping plants together that have similar water requirements). Installing a rainwater collection system.

Get Certified
When shopping for energy- and water-saving products, don’t assume that all product claims are true or that product savings are additive, Richmond says. Do your own independent research, talk to experts, and buy Energy Star- and WaterSense-certified products. These certifications don’t add to the products’ cost, and they save energy, water and money immediately.

Going Solar?
“Do everything you can to save energy in the home itself before you purchase expensive solar panels to create new electricity,” Richmond says. Johnston agrees. “Solar is sexy and insulation is invisible,” he says. “Typically you get a better return on investment on the invisible items.” And if you do decide to put solar panels on your roof, the size (and cost) of the system is determined by your home’s energy use. Reducing your energy use at home first means that you can purchase a smaller solar system, and that saves you money.

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Energy Efficient House

Building an Energy-Efficient Home

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Article written for Time to Build Blog
By Joyanna Laughlin
Energy Efficient House
Tips for Building an Energy-Efficient Home. Don’t wait until you’re shopping for appliances to think about energy efficiency—make it a priority from the start.To build your energy-efficient, dream green home, you need to know where to begin.Orientation
David Johnston, president of the Boulder, Colorado-based green building/sustainable development consulting firm What’s Working, recommends beginning with the orientation of your home on the land. “Orientation and south facing windows can determine as much as half the cost of heating a home,” Johnston says. “Once the house is sited, framed and insulated, it is hard—or expensive—to go back.” Orientation (an aspect of passive solar design) is determined by sun angles and includes sizing south facing windows in accordance with the size of the home. Optimal sun angles are southeast on winter mornings and southwest on winter afternoons. “Breakfast nooks and kitchens are best facing the warm southeast summer sun,” Johnston says. Living areas on the south side are cheerful in the daytime, and bedrooms on the north side can buffer the house from winter cold.

Take Advantage of Thermal Mass

Another principle of passive solar design that makes houses more energy efficient is thermal mass storage in which masonry walls and thick tile or cement floors illuminated by sunlight during the day store that heat and release it into the house at night. Tucson, Arizona-based green builder and solar pioneer John Wesley Miller employs this concept to build highly energy-efficient solar homes in the Armory Park del Sol community of southeast Tucson, which includes one of the first zero-energy homes in the country.While Miller’s territorial, Mission Revival, and bungalow-style homes blend into this turn-of-the century, revitalized inner-city neighborhood, the houses also feature state-of-the-art solar systems and 8-inch-thick, concrete-filled exterior block walls wrapped in rigid foil-facedpolyisocyanurate (a thermoset plastic) board covered with stucco. “What makes solar work better is minimizing your need for it in the first place,” Miller says. The more energy efficient your house is (by utilizing principles like thermal mass storage), the less energy you have to use (from PV or the grid) to heat and cool it.

Insulate, Insulate, Insulate
According to Johnston, insulation is the second most important decision you have to make. It determines the type of framing used, the wall thickness, and many of the trim options around your windows and doors. He suggests including 50 percent more insulation than local code requires. “Builders will try to talk you out of going above code,” he says. “Don’t listen to them. Insulation is the best investment you can make, and it will yield a higher return every year you live in your home than most other investments.”


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energy efficient windows

Building with energy efficient Windows & Lighting

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Written by Joyanna Laughlin for Time to Build

energy efficient windowsShine a Light on Energy Savings
Make windows and lighting a priority in your energy-efficient home

When it comes to building your energy efficient home, it’s not just the big decisions (like orientation and insulation) that are important. Selecting the right lighting and windows has a bigger impact on your energy bill than you might think.

Choose High R-Value Windows
While windows let light and amazing views into your home, they are also a source of heat (energy) loss. A single pane of glass has an R-value of R-1 and a double-glazed window is R-2. According to David Johnston, Colorado-based green building consultant and author of Toward a Zero Energy Home, if your home’s walls are insulated to R-30, you could be losing 15 times more heat through the windows than the walls. And the low-emissivity (low-E) windows that are considered energy efficient are often only R-3. Johnston recommends shopping around to find windows with even higher R-values. For example, the windows in Johnston’s home and office range from R-7 to R-11. In addition, he suggests shading windows with awnings or overhangs during the summer to keep the sun out of the house.

Focus On Lighting
There’s more to energy-efficient lighting than buying a bulb and screwing it in. The most important things to consider when buying lighting include how light sources works, lumens, and color temperature, says Hyman Kaplan, IALD, PE, owner of the Tucson, Arizona-based lighting consulting firm Hy-Lite Design. Interior home lighting includes ambient (general), task, and accent lighting, and a standard bulb for ambient lighting illuminates differently than a spot light bulb. Kaplan recommends deciding how you intend to use each room in your home before selecting lighting with your design team. If you’re planning on watching TV in the living room, it will require different lighting than if you’re going use it for reading, Kaplan says.

Secondly, people are used to buying incandescent light bulbs by the watt, but it makes more sense to compare compact fluorescent (CFL), LED and halogen incandescent bulbs in terms of lumens, which measure brightness, Kaplan says. For example, a 60W incandescent bulb gives off 800 lumens of light. “Incandescent bulbs are obsolete,” adds Johnston. “CFLs are a transitional bulb, and LEDs are emerging as the bulb of the future.” In addition, color temperature impacts quality of light. An incandescent bulb has a color temperature of 2,800K, providing what most people consider warm, comfortable light, whereas many people don’t like the cool, white light of a 4,100K CFL. Neutral light is 3,500K. Whichever lighting you prefer, don’t be afraid to speak up and ask questions, Kaplan says. It’s your home, after all.

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