Let the Sun Shine In (Or Keep It Out)

As the price tag of owning and maintaining a home continues to rise, the need to cut costs wherever possible also grows. Take a little time and money now to install energy-efficient safeguards in your home and, rest assured, you'll save money on future heating and cooling bills. Energy-saving features can also increase your home's resale value.

A true energy-efficient home takes advantage of one of the most readily available heat sources: the sun. Unlike the panels and collectors used in the active-solar designs that many people consider unattractive, today's passive-solar designs showcase beautiful greenhouses or sun rooms.

That sunspace -- a south-facing, window-encased room -- serves as the engine of the energy-saving design, gathering and storing heat that is gradually released when needed to warm adjacent rooms.

The sun space needs to face within 30 degrees of due south to harness a useful amount of heat, says architect Charles Koty of New York-based National Home Plans, Inc. National Home Plans designs passive-solar homes and researches the most efficient techniques used to save energy.

A dark-hued floor made of tile, brick, granite or marble, will also increase the room's sun-harnessing power by absorbing and storing energy that will heat the space later, Koty says. A masonry wall increases the storage capacity of the room even more. To prevent losing energy into the ground, the floor needs to be laid on top of insulation and a 4-in. concrete slab.

Sun spaces also need to be well ventilated, Koty says. Fans direct warm air from the sun space into other areas of the home, and also prevent the room from getting too hot. Koty recommends that any sun space should include plenty of curtains to trap the warm air at night.

To a lesser degree, traditional window arrangements facing south also capture solar energy to warm a home. Conversely, only a few small windows should face north. This layout maximizes the amount of warm, heating energy that is absorbed into the home, while it reduces the intake of cold, energy-sucking air.

A homeowner who wants to use a sun space or strategically placed windows to heat a home needs to use well-insulated windows in the design. Otherwise, the heat collected during the day can be lost during the night.

In the past, homeowners opted for designs without many windows, because most acted as vacuums that let out warm, inside air and let in cold, outside air. Recent technological developments in the window industry, however, allow homeowners to enjoy panoramic picture windows, cheery bays and beautiful French doors with high energy efficiency.

To find the most efficient windows on the market today, consumers need to know what questions to ask and where to look for those energy-saving features.

Windows with two or three panes of glass -- called double-or triple-glazing -- trap air and resist heat loss. Some manufacturers also inject a colorless gas like argon between the panes to increase insulation.

A window's energy efficiency is indicated with R-values and U-values. The U-value measures how much heat transfers through a window, so a window with a lower U-value transfers less heat into a home.

The R-value of a window measures how much heat flow a window resists. The higher the R-value, the less heat a window allows into a home. Manufacturers often cite the "center of glass" R-value, which measures only the warmer center of a window. A "total unit" R-value, on the other hand, measures how much an entire piece of glass resists heat flow.

The Hurd Millwork Company, a Wisconsin-based window and door manufacturer, recommends the use of different types of windows on different sides of the home. This method puts windows on each side of the home that are best suited to meet the demands of the location. Windows that face north are well insulated to deflect cold, blustery winds; while windows that face south or west can be geared to deal with the demands of afternoon sun.

Homeowners in warm climates want to find ways to keep hot, stuffy air -- and the sun that generates it -- out of their homes, though, not in. If the proper precautions are not taken when a home is built or remodeled, rooms that face the afternoon sun can be very uncomfortable during those hours of the day.

A common technique used by builders in southern climates to deflect heat is radiant barrier roof decking.

A sheet of aluminum film attached to the roof decking faces into the attic. The aluminum reduces the amount of radiant energy that transfers into the attic and insulation. This radiant barrier lowers the temperature of the home and decreases the workload on the air-conditioning.

Builders also use vents and overhangs on the roof to reduce the interior temperature of homes. The overhangs shade the home from sunlight, while vents generate proper air circulation in the attic. The overall square footage of a home determines the total number of vents needed.

No matter what the climate, insulation is a key energy-saving tool. The effectiveness of insulation is indicated, like windows, with an R-value. The higher the R-value, the more effective the insulation.

Check with a local builder or city building official to find out the minimum R-value recommended in your region. Be sure to use insulation with an R-value equal to, or greater than, that recommended level.

A final measure used to cut utility bills happens outside the home, not inside. According to studies by the U.S. Department of Energy and the U.S. Forest Service, careful landscaping can trim heating costs by up to 30 percent, air conditioning costs by 50 to 75 percent, and water bills by up to 40 percent.

One of the simplest landscaping techniques used to cut utility costs is the strategic placement of trees. Deciduous trees on the west shade a home from intense afternoon sun during the summer. After those trees shed their leaves in the autumn, sunlight reaches the home and provides free heat throughout the winter.

A few smaller trees or shrubs block late-afternoon sun as it sets.

Evergreens can also be arranged to block chilling winds during the winter or serve as an alley that channels cool summer breezes toward your home.

Landscaping that actually saves energy takes careful attention to detail. A good plan considers the climate, the property and the design of your home. A little time spent on research, however, can save your family hundreds of dollars in utility bills over the years.

The options available for saving energy and cutting utility bills range from simple to complex. Figure out your needs and your resources now, follow through with careful planning and then just wait for the lower bills.