Sunday, February 25, 2007
Beating the big chill
What's the best way to heat your home?
The latest from The Ticker blog
This is yet another winter of energy discontent for consumers. There's confusion, too. Price fluctuations, Mideast turmoil, lingering memories of hurricanes Katrina and Rita all make it hard to budget for keeping warm.
The cost of fossil fuels is down at the moment, but that wasn't always the case. The warm winter has kept natural gas supplies high and prices low, said Sara Banaszak, senior economist with the American Petroleum Institute. But in 2005, after prices spiked post-Katrina, oil recovered much more quickly than gas.
"[After] the hurricanes we were able to more quickly replace oil supplies, whereas we lost production of natural gas," Banaszak said. "Natural gas was priced exorbitantly." And it could happen again.
Electricity rates are rising, prompting more than 12,000 customers of Appalachian Power Co. to file written protests with the State Corporation Commission about the utility's most recent rate increases.
And homeowners are constantly bombarded with energy-saving advice from the government, consumer groups, and utilities and companies that sell and repair heaters of every stripe.
"Weatherstripping can save you up to 15 percent in heating and cooling costs," says Lowe's on its Web site.
"Ask your heating and cooling contractor to check ducts for air leaks and balanced airflow," suggests the U.S. Department of Energy.
"Add a layer to your attic insulation," advises insulation maker Owens Corning.
Besieged by such direction from the well-meaning and the profit-minded, consumers can feel alone and confused.
Linda Hutchinson of Goode saw her electric bill almost double from 2005 to 2006 despite, she said, keeping her heat low and having a newly built home with new energy efficient appliances.
Heating bill in hand, some may feel like making a change in the form of energy they use. Spring might be the best season to do that.
For one, fuel costs are on our minds this time of year. "We think about becoming more energy efficient in the winter because our comfort is associated with it," Lowe's spokeswoman Karen Cobb said.
And Chris Brooks, president of FurnaceCompare.com, which provides data to heating and air-conditioning contractors, recommends that "people buy a furnace when they don't need to. The worst situation is when it's freezing cold outside and your furnace doesn't work. In that situation you don't have the time to compare quotes at your leisure."
Further, Brooks said spring is the time when furnace manufacturers tend to offer discounts. "If you're buying a top-of-the-line system," he explained, "you may be able to save a thousand dollars, give or take, by cashing in a spring promotion."
There are benefits -- and drawbacks -- to every method for heating a home. Safety, convenience and environmental impact might all play a role if you're choosing a new furnace. But the cost of the fuel is probably the biggest factor.
Comparing the costs isn't simple. Manufacturers may claim that their systems could cut energy bills by so much for a typical house. But there is no such thing as a typical house, because what it takes to keep it warm depends on so many factors.
The basics, such as the size of the structure, the layout of rooms, the number of doors and how well the walls (and especially the attic) are sealed are the most obvious factors, but there are others.
How much air leaks into your home is at the top of the list, according to Cobb, the Lowe's spokeswoman. Whether your attic, basement, or even dryer vents and outdoor faucets are sealed can make a difference.
Your water heater needs fuel, too. A home with modern clothes washer or dishwashers will use less hot water -- and less energy -- than one with older appliances. Ditto for one with a programmable thermostat, which Lowe's estimates could save up to $100 per year by lowering the heat overnight and turning it on in the morning.
The number of ceiling fans (which circulate warm air), how much sun the house gets, and even what color the roof is can all affect your energy costs.
Burn for the buck
You can compare the cost for different fuels to heat the same house, but with oil priced by the gallon, gas by the therm, and electricity by the kilowatt-hour, it's not as easy as, say, comparing corner gas stations. And when you toss in "system efficiency," it becomes more of a mess.
But it's a mess that can be cleaned with some basic math.
The first thing to do is find the common ground. That's BTUs -- British thermal units. Whether you're talking about oil, gas, electricity, or even wood or coal, your home needs so many BTUs per hour to keep it warm. You only need to figure what it costs for each type of fuel to produce it.
To be sure to compare apples to apples, we'll look at the costs of heating an imaginary 2,000-square-foot Roanoke-area house. According to data from Criterium Engineers, a national home inspection company, in this region a typical house requires about 30 BTUs per hour to heat each square foot. Thus our comparison house needs 60,000 BTUs per hour to keep it warm.
And let's say we heat it for 10 hours a day during the month of February. That's 280 hours. Doing the math tells us we need 16.8 million BTUs.
With that number in hand, it's easy to calculate how much it would cost to heat the house using gas, oil, electricity, propane or even wood.
When you burn a fuel, not all of it will actually heat your home. Some will leak from the furnace into the surrounding area, some goes up the chimney, and some is lost in the piping or ductwork.
Because of this, every furnace has an efficiency rating: the AFUE, or Annual Fuel Utilization Efficiency from the U.S. Department of Energy.
According to the DOE, the average gas furnace in use today has an 85 percent AFUE, while the average oil or propane system is about 80 percent efficient. A central electric system is about 97 percent efficient. Burning seasoned firewood is about 77 percent efficient, while wood-pellet furnaces hit about 83 percent according to the U.S. Forest Service's Forest Products Laboratory.
We need to apply those percentages when we calculate how much of each fuel is necessary to generate that 16.8 million BTUs.
Gas
Natural gas is measured in therms, and each therm produces 100,000 BTUs; we'd therefore need about 168 therms to heat our comparison home.
But because a typical gas-heat system is only 80 percent efficient, we only get about 80,000 BTUs per therm, so we'd actually need about 210 therms for the month.
Gas and "distribution system costs" from Roanoke Gas cost $1.25 per therm for 54 therms, then $1.15 for each additional therm. Bottom line: We'd need $220 worth of natural gas.
Oil
Oil is measured in gallons, and each gallon produces 134,500 BTUs; we'd therefore need 125 gallons to heat our comparison home.
But because a typical oil-heat system is only 80 percent efficient, you really only get 107,600 BTUs per gallon, so we'd need about 156 gallons of oil for the month.
The average price of a gallon of fuel oil in Virginia is $1.68. Bottom line: We'd need $262 worth of oil.
Electricity
Electricity is measured in kilowatt-hours, and each kWh produces 3,413 BTUs; we'd therefore need 4,922 kWh to heat our comparison home.
But because a typical electric-heat system is only 97 percent efficient, you really only get 3,311 BTUs per kWh, so we'd need about 5,074 kWh for the month.
Residential electricity in the Roanoke area costs about 7.1 cents per kilowatt hour, courtesy of Appalachian Power. Bottom line: We'd need about $360 worth of electricity.
Propane
Propane is measured in gallons, and each gallon produces 95,475 BTUs; we'd therefore need 175 gallons to heat our comparison home.
But because a typical propane system is only 80 percent efficient, you really only get 76,380 BTUs per gallon, so we'd need about 220 gallons for the month.
The average price for propane in Virginia is $2.31 per gallon. Bottom line: We'd need about $508 worth of propane.
Other factors
There are, of course, other factors to consider besides the price. You may not have access to a gas main. If you have frequent blackouts, that might make electricity a bad choice. You might be concerned about getting oil delivered during a heavy snow.
There are environmental considerations as well. Gas tends to burn cleaner than oil, for example. Electric systems may seem cleaner, but are in fact among the dirtiest because that electricity is produced by burning coal -- a process that has a larger carbon "footprint" and contributes more to global warming than other energy sources do.
You might also take a shot at predicting future economics. Electric rates have increased sharply in the past year and are only regulated in Virginia through 2010. After that, the crystal ball is cloudy. Still, as the aftermath of hurricanes Katrina and Rita showed, oil and natural gas prices can jump suddenly and unexpectedly.
Finally, there's the cost to change. Is it worth spending $5,000 to switch to a heating unit that you figure will save you $100 per year? Are you willing to wait 50 years for the payoff? Southwest Virginia's mild winters mean it takes longer to reap the benefits of higher efficiency than it would in, say, Fargo, N.D.
For that reason, even if you have to install a new heating unit, some experts recommend a less expensive, lower-efficiency model. According to Consumer Reports, the difference between a unit with an AFUE of 80 percent and one with a 90 percent rating could be as much as $1,000.
It's easy to spend $6,000 or more on a new heating system, depending on a host of factors -- the kind and size of your new furnace, how much of your existing pipe or ductwork you can use, whether you need a new fan unit, and so on. A new heating unit can cost anywhere from $2,000 to more than $10,000.
But there are distinct advantages to replacing what you've got. If your existing burner is more than 15 years old, there's a good chance it gobbles fuel. According to the DOE, furnaces built in the 1980s are probably only 65 percent efficient at best. That means at least 35 percent of what you're paying for goes up in smoke.
By law, any gas furnace sold today has to have an AFUE of at least 78 percent, and modern gas furnaces can be rated up to 97 percent efficient. Depending on how bad your current furnace is, and how good a replacement you get, the DOE estimates you could cut your fuel costs by almost half. Those are dollars going right into your pocket and offsetting the cost.
Further, until Dec. 31, if you replace your existing furnace with one that has an AFUE rating of 95 percent or better, you can claim a $150 tax credit.
No matter what fuel you choose (or are stuck with), there are some things you can always do to keep costs down. Annual tuneups are a good idea. If you have a forced-air system, leaky ductwork means money is seeping out of the system without keeping you warm; check into sealing it. If you have a steam system, see if it can be replaced with one using hot water instead, which is more efficient.
Of course adding attic or wall insulation, sealing doors and windows from drafts, and turning off your hot water heater at night are the simple and time-honored ways of cutting your energy bill.
And you could always put on a sweater.
