Home improvement can pay for itself, and even put cash back in your pocket – if you’re putting your money in the right places.  Renovations that increase your home’s energy efficiency aren’t just nice for the environment, they can be economical as well.  The folks at One Block Off The Grid offer a great guide to help you sort out which upgrades make the most sense for your home.

The graphic highlights a range of improvements, both big and small, that will cut your utility bills while reducing your home’s environmental footprint.  Each project is marked with four key figures:  average annual savings, projected savings over a 20-year period, the amount of time for the project to pay for itself, and the cost of the renovation.

(click to view the full size image)

The handy illustration points out that in terms of financial investment, many of these home upgrades can offer a better payoff than traditional investments like stocks or CDs.  And depending where you live, incentives like rebates and tax breaks can make the renovation costs substantially cheaper.

These aren’t just long-term projects, either:  upgrades like low-flow showerheads and programmable thermostats can pay for themselves in less than a year, making them a good choice for renters as well as homeowners.  Larger scale renovations on the other hand, like a green roof or solar array, have the potential to save a homeowner tens of thousands of dollars over the years.

(via One Block Off The Grid)

The newest generation of home heating stoves, which burn fuel pellets instead of firewood, can be a great choice for fending off winter’s chilly temperatures.  Pellet stoves are available in a wide range of styles and designs, and they can provide an extremely fuel-efficient source of heat.

Forget about comparing these high-tech models to old-fashioned open fireplaces.  Traditional fireplace designs don’t allow wood to burn very efficiently, causing unnecessary pollution while much of their heat gets wasted up the chimney.  Modern pellet stoves, on the other hand, are 75-90% efficient with particulate emissions up to 5 times lower than even EPA-certified wood stoves.  A cubic foot of pellets also provides up to 5 times more heat output (measured in BTUs) compared to an equal amount of cordwood.

But what about the carbon footprint of all that burning?  Well, any wood you burn that would have otherwise decomposed is essentially a wash, since all the carbon sequestered in wood is emitted as it decomposes anyway.  The carbon in other fuels like petroleum, however, would simply stay put if it wasn’t burned for fuel.

Pellets contain much less moisture than cordwood, which means they burn hotter and they are lighter to transport.  Homeowners can further reduce their embodied energy by using locally produced pellets whenever possible.  As a bonus, bags of pellets are also generally much more convenient to handle than piles of logs.

A Pellet Fuel Stove From Harman Stoves

Pellets can be produced from a variety of sources like sawdust, agricultural waste, and even paper waste; some manufacturers only use source wood that has already been killed by disease or pests.  For example, Colorado-based New Earth Pellets manufactures their fuel from pine trees damaged by the invasive Mountain Pine Beetle.

Pellet stoves aren’t perfect for everyone; they are generally more expensive than traditional stoves, and they often require electricity for their circulating fans.  But they can usually be installed with a simple vent (instead of an expensive chimney), and there are pellet stoves to match any room size or decor.  Homeowners may also qualify for rebates or other incentives to help offset the cost of installation, like Vermont’s $500 credit for switching from oil to pellet stove heating.

You can find more information at The Department of Energy’s EnergySavers website.

(via ModernEnviro)

Who says that a home with cutting-edge energy efficiency has to look like an ultra-modern pod? This recently completed Wisconsin home packs so much energy tech that it makes money by selling electricity back to the grid, and it still keeps a low neighborhood profile.

Neumann Developments, the creators of the home, state the following as the goal of the project:

“Constructing an economically viable mainstream home that will produce more energy than it consumes – allowing for a dramatic reduction in greenhouse emissions and dependency on foreign oil.”

Tracking Solar Array (photo: Neumann Developments)

Two solar arrays are the heart of the property’s electricity generation. A Wattsun solar tracking array in the back yard provides 4,600 kWh of electricity annually, which is dedicated to charging an electric vehicle. Another rooftop photovoltaic setup provides 14,700 kWh yearly, which is much more than the home requires. Surplus power is sold back to the municipal grid for a substantial profit – in July, the home made $408.16 from the local energy utility.

Further energy efficiency comes from the geothermal heating/cooling system in the basement. Glycol fluid circulates through tubing buried below the foundation where the temperature is a year-round 54 degrees. The heat-exchange system provides all necessary summertime cooling, and eases heat production in the winter.

Geothermal Heat Exchange Unit (photo: Neumann Developments)

Energy Star appliances and top-notch insulation round out the home’s energy efficiency. And although the specialized solar and geothermal gear did add a substantial amount to construction expenses, the cost of the upgrades was cut in half by rebates and tax credits.

For more information, visit the Neumann Developments website.

(via Dvice)

“Low-E” Windows Maximize Buildings’ Energy Efficiency (photo: EWC)

Low-E stands for low emissivity, and these windows are constructed to minimize heat transfer through the glass. Since windows are essentially huge holes in the walls of a building, choosing a low-E window design that’s appropriate for local climate and architecture can greatly increase a structure’s thermal efficiency, while reducing energy use and utility costs.

How does it work? A low-E window uses a microscopically thin layer of metal or metal oxide as a coating on the glass, which prevents heat from being transferred through the window. This coating can either help to keep a building cool in hot weather, or it can prevent heat loss in the cold winter months.

Low-E glass can be customized for different amounts of solar gain, meaning heat from sunlight. For example, a structure in a cold climate would benefit from a window that prevents heat loss, but admits as much heat from sunlight as possible. Low-E glass is typically transparent to visible light, so it shouldn’t be confused with the tinted or mirrored glass commonly seen in commercial buildings.

Low solar gain design for hot climates (photo: EWC)

The performance of a low-E window is usually described as its “U-factor” or “U-value”. Simply put, this is the inverse of the “R-value” that is commonly referred to in describing insulation materials. So, whereas a high R-value (resistance to heat transfer) is a good thing for insulation, the U-value (heat flow) will be a very low number in an energy-efficient window.

Low-E glass is often combined with other design elements to maximize a window’s energy efficiency. Two or more panes of glass create added insulation, and the gaps between panes may be filled with an inert low-conduction gas like argon or krypton. And remember, the installation is just as important as the design of a window. To enjoy the efficiency benefits of low-E windows, the window frames must be properly mounted and sealed to eliminate any drafts or leaks.

(via Efficient Windows Collaborative)

Interior Of A Tankless Water Heater

Tankless water heaters have been used in Europe and Asia for 50 years, and they are gaining popularity in the US. Right now they represent about 8% of new sales in the US. Tankless heaters, also called on-demand, flash or instant water heaters, qualify for a $300 federal tax credit.

How efficient are tankless water heaters?

Tankless water heater are about 10%-20% more efficient than tanked heaters, depending on circumstances. The problem with tanks is that heat leaks out of the tank, and the heater has to constantly reheat the water, 24 hours a day.

Tankless water heaters are available in propane (LP), natural gas, or electric models. They come in a variety of sizes for different applications, such as a whole-house water heater, a hot water source for a remote bathroom or hot tub, or as a boiler to provide hot water for a home heating system. They can also be used as a booster for dishwashers, washing machines, and a solar or wood-fired domestic hot water system.

A Woman Using A Point-Of-Use Water Heater

Some statistics: Water heating accounts for 20%-25% of an average household’s annual energy use. The American Council for an Energy-Efficient Economy determined that total cost for a tankless water heaters is less than for standard water heaters over a 13-year period. The U.S. Department of Energy site states that you can save up to 30% of the energy you currently use with a tank heater. But the American Council for an Energy-Efficient Economy says to expect only a 10%-15% reduction in water heating energy used.

Gas-powered tankless water heaters are the most efficient, but are the most difficult to install and require venting.

Electric tankless water heaters are somewhat more efficient than tank electric heaters (about 8% more efficient), but are generally less efficient than gas-heated tank water heaters. Since electric tankless heaters are less powerful, their flow rates are generally limited to 1-3 GPM. Point-of-use electric heaters (see the WaiWela mini heaters below) are great for a remote faucet or bathroom where usage is minimal and the flow rate is small.

However, when comparing water heaters, a number of factors have to be weighed: the cost of installation, how hot you like your water, the number of people in your household, and the cost of gas and electricity in your area.

Let’s quickly review the advantages and disadvantages of tankless water heaters:

Advantages:

• Uses less energy (eliminates heat loss in tanks and through pipes)
• Continuous hot water (hot water doesn’t run out)
• Long life-span (20 years versus 13 for a tank heater)
• Compact size

Disadvantages:

• Some tankless heaters have difficulty coping with large households
• More expensive than tank water heaters
• Owners may wait longer for hot water to arrive at a faucet (depending on installation)

With tankless water heaters, there is a short delay between the time when the water begins flowing and when the heater’s flow detector activates the heating elements or gas burner. In the case of continuous use applications (showers, baths, washing machine) this is not an issue. However, for intermittent use applications (for example when a hot water faucet is turned on and off repeatedly) this can result in periods of hot water, then some small amount of cold water as the heater activates, followed quickly by hot water again.

Installing a tankless system comes at an increased cost, particularly in retrofit applications. They tend to be particularly expensive in areas such as the US where they are not dominant, compared to the established tank design. If a storage water heater is being replaced with a tankless one, the size of the electrical wiring or gas pipeline may have to be increased to handle the load and the existing vent pipe may have to be replaced, possibly adding expense to the retrofit installation.

Here is a round-up of the best tankless water heaters:

Takagi T-K3 Tankless Water Heater

Takagi heaters were the first tankless water heaters available in North America, and they’ve been manufactured in Japan since 1946. Their current indoor model, the Takagi Flash T-K3  delivers 258 gallons per hour of hot water every hour.

It’s capable of handling water flows ranging from 0.5 – 7.0 gallons per minute, with heating capability of 11,000 to 199,000 BTU (the widest range on the market). It’s all controlled by a computer board and sensors checking for flow, temperature and demand.

The only complaints about Takagi heater we’ve seen are the same as those about tankless water heaters in general– that it takes a while for hot water to flow, and that flow rate is reduced when inlet water is cold, or when many people are using the hot water at once.

The Takagi Mobius model is capable of producing a rate of flow approaching 10 GPM, making it ideal for central water heating. You can link up to 20 Mobius units together using one main control system. Note that with most gas-supplied demand heaters, significant input BTU is required to ensure proper and safe operation

You can find Takagi heaters at Amazon and  Low Energy Systems.

Stiebel Eltron Tankless Water Heaters

The Stiebel Eltron company was established in Germany in 1924, and they’ve been selling their quality heaters in the US since 1980.

Like Takagi’s heaters, Stiebel Eltron’s gas or propane tankless water heaters are equipped with temperature sensors that continuously monitor the incoming and outgoing water temperatures, and the temperatures can be controlled to within one degree by using the digital controls provided.

Stiebel Eltron heaters are warranted for three years, and sell for about $700-$800.

Stiebel Eltron heaters are available from Low Energy Systems and Amazon.

Paloma Tankless Water Heaters

Paloma began operation in 1911 in Japan, and they are a major gas appliance company in Japan. The Paloma Group also owns the US company Rheem.

Paloma makes large capacity heaters, which can serve large households and even small businesses. They work well in homes with low-pressure, or in homes where there no electrical power or intermittent power. For example, the Paloma 28c model is said to be able to serve “the needs of a small restaurant kitchen, a school shower facility, or a large National Guard training base”.

Paloma claims to have unique safety features built into their heaters. All of Paloma’s indoor tankless water heater models are equipped with a system to monitor and correct combustion conditions that could lead to carbon monoxide production. These models are also equipped with an Overheat Limiter Film Wrap designed to detect overheating all around the heat exchanger.

Paloma heaters are available from Low Energy Systems.

WaiWela Mini Instant Water Heaters

Waiwela heaters are made by Paloma. They are compact electric heaters which actually contain a small tank. These point-of-use heaters are usually installed under a sink. They plug into a regular 120V household electric socket, and provide instant hot water, thus saving water because you don’t wait for the hot water.

There are two models available: 2.5 gallon Waiwela, and 4 gallon Waiwela. Both are 110 VAC, UL approved, and they are warrantied for six years.

They are available from Low Energy Systems.

Solar Water Heating and Tankless Heaters

What would be the most efficient way of heating water? Using direct solar water heating, in combination with another renewable source such as wood and biomass (cleanly burnt), and biogas. Biogas can be used in a LP gas water heater, but it is not commonly available in the US.

A solar water heater can reduce your hot water heating bill by 60 to 95 percent, potentially saving hundreds of dollars a year. However, upfront and installation costs can be high, anywhere from $1,500 to $5,000, although there are federal tax credits available.

A tankless heater will also work as a backup, as long as it is designed to accept hot-water input (not all of them are).

Solar energy is often used to heat water or generate electricity, but it can also be used to heat air. The SolarDuct is a new device that uses sunlight to heat air before it enter a ventilator. They are modular units that can be installed on buildings with flat roofs.

SolarDucts can also be used to remove heat from the back of traditional solar panels. Conserval Engineering is introducing the SolarDuct PV/T, which is a combination of solar photovoltaic and solar thermal in one assembly. The SolarDuct technology is based on their successful SolarWall product, which is being used by the US Army, Canadian Government, NASA, Ford, Federal Express, Wal-Mart and 3M.

^{The SolarWall at the 3M plant in Perth, Ontario saves the company about $6000 per year in heating costs.}

Note: This post has been expanded and updated for 2009!

Tankless water heaters only heat water when it is needed. About 8% to 30% of the energy consumed by a standard water heater goes to keeping the water hot while it’s not being used. New tankless systems heat the water instantly when you turn on the faucet, rather than keeping a tank full of hot water 24/7 whether you’re using it or not. Tankless heaters run on either electricity or gas, just like regular heaters. They start out at about $300 for electric and $600 for gas.

There are two main brands of whole-house electric tankless water heaters: Stiebel Eltron and Powerstar. They come in various models, which are rated on the “gallons per minute” that they deliver.

The online store Low Energy Systems has a good selection of tankless water heaters, both electric and gas-powered. You can also find tankless water heaters reviewed on Amazon–this is one of the few places you’ll find reviews from owners themselves.

See more information about water heaters and electrical savings at Ask Mr. Electricity

Incorporating a Trombe Wall into a house is one of the most efficient ways to capture the heat of the sun. They work in the mildest to the most severe of climates.

Basically, sunlight strikes the wall through a window, and the Trombe Wall heats up, causing warm air to flow into a room.

Trombe walls are located on the south side of houses. Clear glass is situated three to six inches away from a mass wall (one made out of concrete, rammed earth or dense masonry). See our post on The Solar House: Free Heating for more information.

Using stone to capture heat from the sun is metaefficient.

People often think of using solar energy for producing electricity, but it is actually easier to harness the power of the sun to heat your home. It’s free heat that has been utilized since ancient times but few modern architects or builders really understand the principles involved. The Solar House, by Dan Chiras, explains architectural techniques that can be incorporated into a house to capture heat and store it. The techniques use ordinary building materials and work in both cold and warm climates. They add little expense to the overall cost of a home. See more about this book on the author’s web site. See also Passive Solar Home, which is another book that explains solar heating.

Available from Amazon for $19.77