Chesapeake Home

The systems for converting solar energy to electricity are costly but can help eliminate dependence on non-renewable resources. Photo courtesy Solar Works

With fuel and electric costs at an all-time high, many homeowners are wondering what to do to protect their pocketbooks. Turning back the thermostat and turning off the lights hardly make a dent when fuel prices are climbing in dollars, not cents. And then there are growing fears about global warming. Statistics from the U.S. Energy Information Administration suggest the building industry contributes to 50 percent of all U.S. global warming emissions each year.

Use the Earth’s Interior to Heat and Cool
While many new gas and oil furnaces have made massive strides in efficiency over the last several years, have you ever considered what life might be like without a fuel oil or gas bill? Ground source (also known as geothermal) heat pumps provide a way to heat (and cool) the home using minimal electricity and drawing on a fairly consistent ground temperature as a “fuel source.” “When you say geothermal, some people think you’re talking about drilling wells in Alaska,” says John Preston, Eastern Region Manager for WaterFurnace International, which manufactures and sells ground source heat pumps. “But what you’re doing is using the earth to heat and cool your home.”

Geothermal heating systems look similar to conventional furnaces, heat pumps, and boilers. Photo courtesy Water Furnace International

Unlike a conventional heat pump, which draws on outside air for heating and cooling, a geothermal system draws warmth from deep inside the earth via vertical or horizontal pipes circulating water or environmentally safe antifreeze through a loop under the ground or submerged in a pond. “There’s more energy in the ground,” says Preston, “than a house can ever use.” In summer, the system pulls warm air out of the home and puts it back into the ground or, if you have the optional desuperheater, back in your hot water heater for free hot water whenever the unit is running.

In layman’s terms, one can think of a geothermal system like a basement.  In winter, basements tend to be warmer than the rest of the home and cooler in summer. That’s because the earth is at a relatively constant temperature. Unlike a conventional heat pump, which has to heat freezing air, a geothermal heat pump is working with the ground that averages 50 to 55 degrees year round.

Homeowners with a geothermal heat pump can expect cost savings up to 70 percent on their utility bills over a conventional heat system. Preston contends that “nearly all new construction can show a positive cash flow from day one of installation, compared to other renewable energies that can take 20-80 years to show any type of return on investment.”

While geothermal systems tend to be more common in new construction, more homeowners are retrofitting to accommodate geothermal. Preston says a geothermal system is usually about a third more expensive than other high-end heating and cooling systems, mainly because of the cost involved in putting loops into the ground.  But homeowners don’t have to live on a farm or own a pond in order to take advantage of geothermal heating and cooling.  Vertical loops enable homeowners even on small lots to install such a system.

However, Preston advises against jumping on the geothermal bandwagon without first analyzing the quality of your home’s insulation and assessing where it leaks air. “Your house needs to be part of the system,” he explains. “All the money you spend to heat your home can go right out the window if you have leaks and lack proper insulation.”

Tighten The Building Envelope
Leigh Seddon, founder of Solar Works, Inc., in Montpelier, Vermont, says even a home outfitted with the latest in energy efficient technology won’t perform the way it should if homeowners aren’t paying attention to air infiltration. Green builder and consultant Carl Seville of Seville Consulting in Atlanta, Georgia, agrees, noting that standard fiberglass insulation can often be problematic, as it is more prone to gaps and compressions. He recommends spray foam insulation.  Ceilings are particularly vulnerable. “One of the best solutions I’ve seen is to use spray foam insulation on the underside of the roof deck, creating an insulated and sealed attic,” he says.

Polly Bart, owner of Greenbuilders, Inc., in Butler, Maryland, says even if a builder uses conventional fiberglass batting for insulation, one can increase a home’s insulating capacity by using 2 by 6 studs instead of the usual 2 by 4 for framing. “That leaves room for more insulation,” she says. Bart says another big drain on energy efficiency is the cathedral ceiling. While it is a popular architectural feature of modern homes, “they’re hard to heat and insulate,” she explains, advising that homeowners are better off with lower ceilings and attic space overhead.

Another overlooked area of air infiltration is the crawlspace, which, if vented and not insulated, can lead to cold floors and major heat loss. Seddon says other culprits where heat gain in summer and air infiltration in winter can occur are old or poorly installed skylights and recessed lights. Big skylights can let in a lot of heat in summer. Often, recessed lights lack insulation and can let in cold air from roof and attic spaces. Homeowners can reduce costs for a high ceiling by setting ceiling fans correctly for summer and winter. Most fans have a switch on the side that reverses the direction of rotation for healing or cooling.

Of course, windows and doors are major areas for air leakage, particularly for homeowners with older houses.  Bart recommends updating old windows with low-E, argon gas-filled, double-pane windows, which are pretty much the industry standard now. “Don’t put in cheap windows,” she says. Good windows will pay for themselves in what they save on heating and cooling costs, as will well-insulated doors. While wood and glass doors are certainly the most attractive, they won’t protect against heat and cold as well as solid insulated doors. Homeowners who purchase French doors, for example, should make sure they invest in insulated glass.

Take Advantage of the Sun
There are a variety of ways homeowners can take advantage of the sun’s energy to heat and power their homes.  The least expensive option is passive solar design. While it’s easier to take advantage of passive solar energy in new construction, homeowners can also use some of its concepts in existing homes. The first key is having a tight building envelope to hold in heat during the winter and cool in summer; the second key is the orientation of the home. The long axis should face south, and the residence should have many windows designed to take in the sun’s warmth on winter days. Seddon says taking advantage of passive solar design can reduce a home’s energy consumption by 30 percent. In winter, it can significantly minimize the home’s need for its heating system.

Photo courtesy Power Up

Even a homeowner living in a house that doesn’t meet the site orientation or design ideal for solar gain in the wintertime can still make small, low-cost adjustments to take advantage of solar energy. The south side of a home, for example, should have minimal coverage from trees. However, trees can be beneficial on the west side of the home by cutting down on heat gain in the summer. A home that wasn’t designed to take advantage of southern exposure can benefit from a well-placed sunroom on the home’s south side, which will draw in natural heat during the winter. Seddon says installing tile floors over concrete will create a storage area for heat to preserve its warming effect even once the sun has gone down.

Solar Hot Water Heater Savings
Solar hot water heaters draw heat from collectors and preheat water in a storage tank. According to Peter Lowenthal, group director of Renewable Energy and Clean Technology for communication firm 360jmg, typical energy savings are $400 to $1,000 a year. Costs are between $6,000 and $8,000 for the system and installation. Grants and tax credits can be as much as $3,000. Systems should pay for themselves in four to seven years. Left by Power Up. Middle & Right by Solar Services.

Maryland Solar Grant Program
Solar Hot Water Heating: 20 percent of system cost up to $2,000.
Residential Photovoltic (Solar Electricity): 20 percent of system cost up to $3,000.

Tankless Hot Water Systems
As electric costs rise, many homeowners are becoming interested in photovoltaic systems. “PV systems use silicon wafers to convert sunlight into electricity,” Seville explains. This allows homeowners to generate their own power, and often they can sell excess power back to the electric company. Once upon a time, PV technology required the use of large unsightly solar panels, but Bart says that’s changing.  Now, PV systems can consist of solar tiles that can be laid on the roof and look like regular roofing tiles.

For a family with high hot water use, Bart says the best way to take advantage of the sun’s energy and save money at the same time is to install a solar hot water heater. This water heater works by having active solar collectors on the roof with a metal plate under glass that helps heat water. While a solar hot water heater can cost anywhere from $4,000 to $7,000, long-term savings can be substantial.  “Hot water is the second highest energy consumer in a home after the HVAC system,” notes Seddon. “An average family of four,” he says, “will spend $500 to $800 a year on hot water.” Many states now offer tax credits to homeowners who install solar hot water heaters, thus minimizing the initial financial outlay.

Another option for saving money on water heating costs, according to Bart, is installing one or more tankless (or on-demand) hot water heaters in the home. Since tankless hot water heaters don’t use energy to heat stored water, they can save on energy costs, as they only heat water as it’s being used. A typical tankless hot water heater can provide two to five gallons of hot water per minute. For homeowners who plan to use hot water at two different locations simultaneously, more than one hot water heater may be required. Taking a shower and running a dishwasher, for example, can push the limits of a tankless water heater. A family that uses less than 40 gallons of hot water a day can save as much as 35 percent on energy costs over a conventional storage water heater. A large family that uses a lot of hot water, however, will not save as much and maybe nothing at all if using a gas-powered demand water heater, which can waste energy with a constantly burning pilot light.

Earth, Wind, and Fire
As homeowners try to beat rising energy costs, the most important thing to remember is that greatest efficiency is achieved when tapping into the natural warmth of the earth, eliminating drafts and increasing insulation, and drawing on the sun’s energy are all working together.

You can get a professional evaluation of your home’s current level of energy efficiency and recommendations for improvement by ordering an energy audit for a few hundred dollars. For more information on finding a consultant and for other tips on making your home more energy efficient, visit the U.S. Department of Energy (eere.energy.gov/consumer your_home).

Deborah Huso is a freelance writer with a specialty in eco-friendly and energy efficient building practices.

Contacts:
Geothermal Heat Pump Consortium: geoexchange.org
Green Builders: greenbuilders.com or 410-833-4814
Power Up: powerupco.com or 410-344-9206
Seville Consulting: sevilleconsulting.com
Solar Energy Industries Association: seia.org or 202-682-0556
Solar Works, Inc.: solar-works.com or 800-339-7804
WaterFurnace International: waterfurnace.com or 800-GEO-SAVE