Wow! What a Whopping Heating Bill - Richard C. Taylor, associate professor of plumbing and heating.
No one needs convincing that this is the time to do something about rising home-heating costs. Fuel-oil prices have at least tripled, and natural gas and electric prices are zooming up. Where should I start? In what should I invest?
Think of your house as a leaky heat bucket. Think of your heating system as a pump that squirts heat in to keep up the comfort level in that leaky house-bucket. You can readily see that you can reduce fuel expenses by sealing the bucket to slow the leaks, as well as improve the efficiency of the pump. These are the two basic approaches that should be pursued to lower your heating bill: Slow the heat loss of your home, and improve the efficiency of your heating system. It will help if you prioritize your efforts (and money) by identifying which is worse: the building shell or the mechanical heating system. Let's talk about both in turn.
Homes lose heat mainly in two ways: through the outside building surfaces and by air leaking in and out (called air infiltration). There is a good reason to begin by air-sealing your home, since added insulation often hides air leaks. Sealing your home can best be done by hiring someone to run a test in which a large, calibrated fan is installed in a doorway, and the house is depressurized. This "blower door" test will determine just how leaky the house is and where the major leaks are. Sealing is done with spray foam, waterproof caulk and other airtight materials caulked into larger openings. Can the house be too tight? It is best to make the building as tight as possible - if it becomes too tight (as determined by a "blower door" test), air can be added in the best way to provide good indoor-air quality. Our homes usually leak air in many random locations, and much heated air is lost invisibly. Openings near the top and bottom of the structure leak the most air due to the pressure caused by warm air rising - these should be sealed first.
Insulation is what slows heat loss through surfaces of our home. Insulation is most easily added to attic floors because they are most easily accessible. This insulation can be fiberglass rolls or blown fiberglass or cellulose material. Finished walls are more difficult to insulate, because holes must be drilled into the wall cavities and insulation blown in. A professional can do this best, but the necessary equipment can be rented at home-improvement centers. The more insulation, the better.
Heat also is lost through windows. Many brands of higher-efficiency windows are available with at least two panes of glass, with an inert gas filling the gap, and a low-emissivity coating (low-e). If new windows are installed, make sure all air leaks around the frames are sealed.
The other major area to be addressed is the mechanical heating system. Central heating systems can be fueled by electricity (heat pumps and baseboard electric heaters), natural gas or propane (forced air, hot water or steam) or fuel oil (forced air, hot water or steam). Each fuel, historically, has had its advantages and disadvantages. Currently, fuel-oil prices are rising more rapidly. Historically, natural gas and fuel-oil prices per similar quantity of heat (BTU) have been close to each other; this is likely to be the case in the future. Electricity is usually the most costly fuel to heat with because it is delivered to your home from the power plant at only 30-percent efficiency.
On the other hand, the most efficient heating units are electric heat pumps (especially ground-source heat pumps). These units have efficiency ratings over 100 percent because the heat pump doesn't produce heat; it moves it from outside (or underground) to inside, like your refrigerator in reverse. Concerning heat pumps, caution must be taken when installing them in very cold climates, because they are ineffective at capturing heat in frigid outside air and must fall back on expensive electric second-stage heat. Heat pumps deliver heated air through ducts. See the accompanying "Efficiency Ratings" concerning heat-pump efficiency ratings.
Natural-gas furnaces (warm air) and boilers (hot water) are available at 95-percent efficiency. These are the topof- the-line condensing units. Older, gasfired units typically operate at 80-percent efficiency or worse.
Fuel-oil furnaces and boilers are generally available up to 87-percent efficiency. Ninety-plus efficiency condensing appliances are impractical until low-sulfur fuel is widely available. Older oil-fired units may have efficiencies well under 80 percent. Often, oil-fired boilers also make instantaneous domestic hot water through a submersed coil in the boiler. These are oil hogs because the boiler must keep running full speed all summer long. A more efficient method of producing domestic hot water is to use an "indirect-fired" tank heater. This type of unit stores hot water in a highly insulated tank that is heated as needed by the boiler.
Heat is delivered to your rooms by ducts in a warm-air system or pipes in a hot-water or steam system. Ducts have the advantage of being useful for air conditioning in the summer, but have the huge disadvantage of having invisible leaks. Leaks in the heat-delivery system steal fuel dollars, especially if they leak in unheated spaces. As you can easily imagine, a water or steam leak announces itself to the world by producing a puddle of water or worse. Air leaks go unannounced, because the leaking air is invisible. Ducts in attics and unheated spaces must be carefully and thoroughly sealed or rerouted through heated spaces. Ducts and pipes in unheated spaces should be insulated.
So what should you do concerning your present heating system? If you own an older system, consider having it professionally replaced with a unit with the highest efficiency available. The new unit should be properly sized to meet the heatloss rate of your newly insulated home. Many of the newest and most efficient units have two stages, meaning that, in warmer weather, they can perform like a smaller, more efficient unit while running both stages during the coldest weather.
What about the thermostat? Since heat is used to keep the temperature of the house up to your comfort level, the lower the thermostat setting, the less heat you will use. Not only that, but energy is saved if you lower the temperature of the house (or parts of the house) for periods more than four hours. Most sources agree that you can save about 1 percent per degree that you set back your thermostat temperature for eight hours. A programmable thermostat has the advantage of automatically setting back and restoring the temperature at designated times. This helps if you tend to forget to adjust the thermostat yourself and helps because the house can be warmed up for when you get out of bed or get home from work.
It is possible to save 50 percent of your fuel bill by carefully air-sealing, insulating and upgrading your heating system. A better return on your investment is hard to find. ¦
Where to get good information
Try these sites:
- Pennsylvania Housing Resource Center at Penn College
- School of Construction and Design Technologies at Penn College
This author's energy-saving actions
- Programmable thermostat set to 60 degrees at night and 68 degrees during the day
- Installed 95-percent-efficiency two-stage natural-gas furnace with ECM motor (got tax rebate)
- Added blown-in cellulose insulation to 1950-era walls
- Had a blower-door test and air-sealed major air leaks
- Sealed ducts with duct mastic
- Added 1-inch insulation board to the exterior of the house when vinyl siding was installed
- Added insulation to basement walls (especially above grade)
- Richard C. Taylor, associate professor of plumbing and heating
Green tips from students
Energy-Saving Advice From Students
Students pursuing bachelor's degrees in heating, ventilation and air conditioning design technology presented tips for saving energy around the home during the college's Environmental Awareness Week, hosted on campus April 21-25.
Among their tips:
Heating and cooling systems:
Jeffrey W. Stoltz Jr., Milesburg To help improve heating efficiency, apply duct mastic to joints and seams. The compound is painted on, then hardens to seal duct work. Duct mastic is available at HVAC supply stores; buy one that is rated for all systems.
Deshawn M. Alexander, Nassau, N.Y. Look into technology to recover heat lost from your heating and ventilation system.
- Condensing technology recaptures hot gases and can operate at 90 percent efficiency.
- An energy-recovering ventilator recovers energy from lost air and transfers it to fresh air coming into your home.
- Geothermal technology takes heat from the earth and distributes it into the structure; to cool, it transfers heat out of the structure and returns it to the earth.
Wesley J. Hetrick, Shermans Dale
- If planning to install a new HVAC system in your home, you will find a variety of prices. Do a cost analysis. While on some systems, initial costs may be higher, they have added features to help them run more efficiently and eventually pay for themselves in energy savings.
- "Don't be scared off by the initial cost; go for efficiency," Hetrick says.
Appliances Matthew L. Friedhaber, Oil City
- Don't overfill your dryer; use smaller loads.
- Monitor your clothing throughout the drying cycle and remove it as soon as it is dry.
- Clean your lint filter, otherwise it can trap heat inside, reducing your dryer's efficiency.
- Mix heavy and light fabrics
- Dry loads of clothing back-to-back; putting clothes in an already-warm dryer will reduce their drying time.
- Front-loading washing machines cut water use. The most efficient to date uses only 13.3 gallons.
- Some washing machines offer a faster spin cycle, meaning they'll require less time in the dryer, or load sensors that measure the amount of clothing in the machine and allot the appropriate amount of water.
- While washing machines that incorporate the newer technology cost more, they cost less to run over their lifetimes: $1,300 over the lifetime of a "regular" washing machine vs. $600 over the lifetime of the most efficient washing machine.
Daniel L. Young, North Haven, Conn.
- Make sure there is space between your refrigerator's coil and the wall.
- Keep your refrigerator's seals in good condition.
- Clean refrigerator coils regularly. If the coils are under the unit, a coil brush is available to reach under and remove any dust or dirt.
- Dishwashers use less water than even the most frugal human dishwasher; use the no-heat dry cycle.
- You can set oven temperatures 25 percent lower by using glass bakeware.
- Convection ovens, which use a fan to circulate heat, are 23 percent more efficient than standard ovens. Flash-bake ovens require no preheat time.
- Users of standard water heaters pay for the energy to keep water held in the tank at a constant temperature. Tankless water heaters eliminate that need. Visit www.foreverhotwater.com to compare units.
Regulating Your Heat: Christopher M. Marsden, Sandy Hook, Conn.
- Digital, programmable thermostats allow you to schedule the temperature inside your home throughout the day, accounting for such activities as when you awake and when you leave for or return home from work. They can be scheduled to begin increasing your home's temperature before you return home.
- The units can save 30 to 33 percent in energy use.
Drew J. Sepik, Mercer
- Home-heating myth: If you set back the temperature on your thermostat while away, it will take more energy to reheat the whole house again when you return.
- The longer a home stays at a reduced temperature, the more energy is saved. Setting your home's temperature back 10 to 15 degrees while at work or sleeping can save a significant amount on your energy bill.
Paul T. Springer, Lewisburg
- Smart-home systems, previously reserved for the very wealthy, will become more common. Smart homes can include sensors that receive signals as to where the occupants are and can turn up heat and turn on lights in individual rooms.
- Smart-home systems can also manage multimedia and speakers, but the functions that boost efficiency the most control lighting, window blinds, and heating and cooling.