How to Conserve Energy at Home
By Zolton Cohen
What is "energy"? Where does it come from? And how do we pay for it? When you learn the answers to these questions, you can also learn how to live more efficiently in your home. In this article, we'll discuss how to be smart about how you use energy, how to know when to turn electrical power on and off, and how to use natural gas, propane, and fuel oil in the most effective way.
Basic Concepts of Energy Efficiency
You can make a lot of progress toward improving the energy efficiency in your home by simply plugging the many places through which air can get in or get out. Plugging your home is called "air sealing," and it is one of the most important first steps to take when weatherizing your house to increase its energy efficiency.
Increasing the amount of insulation in various places in your home should be a high priority. Insulation, in its many forms, helps stop the transfer of heat from one place to another. A good example of this is the insulation in your attic. A thick layer of insulation helps stop heat flow from the house to the attic during the winter. In the summer, that same insulation helps stop heat transfer from the hot attic to the rooms below.
But while better air sealing and insulation in your home can do a lot to reduce your utility bill, that's not where the story on energy efficiency starts and ends. There are many other ways to conserve, some of which require only simple changes of habit or lifestyle.
Electricity powers lights, appliances, and electronic devices in your home. It also runs air conditioners, heats water, cooks food, dries laundry, and in some cases is used for space heating. Natural gas, propane, and oil are mostly burned to provide space heating and hot water; and secondary uses for these gases include cooking, clothes drying, and fireplace fuel.
Electricity: Electricity enters a home through a service-entry cable either above or below ground. From there it passes through a main electrical service panel containing fuses or breakers and is distributed throughout the house through wires, receptacles, and switches. Electricity is billed to the consumer by the kilowatt-hour (kWH). Each kWH costs approximately 8 to 15 cents, depending on where you live and your utility company's fees.
One kilowatt-hour equals 1,000 watts of electricity used for an hour. To understand how kilowatts are calculated, picture a 100-watt lightbulb. Burning that bulb for one hour uses 100 watts of electricity. If it burns for 10 hours, that equals one kilowatt (100 watts 3 10 hours = 1,000 watts, or one kilowatt). And burning that one bulb for those 10 hours costs between 8 and 15 cents.
Natural gas: Natural gas is delivered to homes through a network of underground pipes. After natural gas passes through a meter outside of a house, the gas is piped to where it is needed inside -- to a furnace or boiler, water heater, or gas fireplace -- through a series of smaller metal pipes. Natural gas is billed to the consumer by the cubic foot of gas used.
Propane: Propane, or liquefied petroleum gas (LPG), is transported by truck from a utility or gas company to a storage tank on a homeowner's property outside the home. From there it enters the house through a pipe and is distributed via a system similar to that used for natural gas. Propane is billed by the gallon.
Oil: Fuel oil is also transported by truck, is pumped into a storage tank either inside or outside the house, and is piped to the appliances where it is needed. Fuel oil is billed by the gallon as well.
So that's how energy arrives at your house and how it is billed. What happens after that -- how you use these energy supplies -- has everything to do with how large your utility bill is at the end of the month. Every time you turn on a light or a TV, use hot water, or switch on the air conditioner or furnace, you consume energy.
Watch the Thermostat
Dialing down: In 1977, President Jimmy Carter appeared on national television for the first of what were later dubbed "energy speeches." The country was going through an oil crisis, and Carter advised us to "dial down" our thermostats. His line of reasoning was that, by reducing the temperature in our homes, we could conserve heating fuel.
President Carter's words of nearly 30 years ago still ring true today: The best way to conserve energy is to not use so much of it. And one of the best ways of reducing the use of heating fuel in the home is to simply turn down the thermostat.
Because space heating constitutes the largest energy expenditure in many homes, even a little conservation of heating fuel goes a long way toward achieving a lower utility bill. Dialing down the thermostat one degree during the winter can result in about 1 to 3 percent less fuel use, and a similar reduction in your heating bill.
A furnace or boiler has to maintain a differential in temperature between the inside of the house and the outdoors in order for the house to feel comfortable. On cold days that difference can be as much as 50 to 60 degrees (say, 20 outside and 70 inside). Any time the differential can be reduced, even by a degree or two, the heating system comes on less often, less fuel is burned, and savings result. The downside of turning down a thermostat, of course, is that the house is cooler. But Carter had a solution for that -- simply slip on a sweater. That makes sense, too. Instead of turning up the heat to increase the overall warmth in the huge volume of space inside the house, you can simply increase your personal insulation to help retain body heat.
Though dialing down might seem a hardship at first, after a while your body will adjust to the "new normal" house temperature and wearing sweaters and socks inside will become a part of everyday life.
Dialing up: The concept of dialing down can be reversed for energy savings during the warm months. "Dialing up" is an effective method of reducing the cost of cooling a house with room or central air-conditioning.
The same principles apply: The less the temperature differential the air-conditioning system has to maintain between the inside and outside, the less often the compressor comes on, the less electricity is consumed, and the lower the utility bill.
Instead of setting the thermostat to the point that the air-conditioning system makes the house cold, try dialing it up a few degrees and adjusting your clothing to deal with the slightly warmer temperature. Chances are you'll never notice the difference. And, as is the case with heating, dialing the thermostat up when you're away from the house results in lower energy consumption.
Close Empty Rooms
If there are rooms in your house that aren't being used, shutting the doors to those rooms results in an overall reduction in the amount of area that the heating and air-conditioning systems have to heat and cool. When a child moves away from home to go to college, or when parts of the basement aren't being used, isolating those areas from the rest of the house means less demand in terms of heating and cooling, and a lower energy bill. The less space you need to supply with conditioned air, the less often the heating, ventilation, and air-conditioning (HVAC) systems will need to operate.
Stay Under the Covers
Many people prefer to "sleep cold," and they don't mind turning down the thermostat into the low 60s or mid-50s at night. Some even like to turn off the heat entirely in the bedroom and sleep with a window open. Those who are comfortable dialing back this dramatically are able to reduce their heating fuel consumption substantially at night, as the heating system does not have to maintain a large temperature differential between the inside and outside.
For those not so inclined, there are means available to stay warm under the covers, even while dialing back the thermostat. Down or synthetic-filled comforters provide insulation with little weight. And electric blankets generate warmth at a small cost in electrical energy.
The winter months can bring with them high heating bills, even for those who like to keep their homes on the cool side. In the summer, air conditioning can make those energy bills skyrocket. In the next section, we'll take a look at how to keep heating costs down in all seasons.
Conserving Energy in All Seasons
Home energy management and control changes with the seasons. There are different steps you can take as the temperature fluxuates in order to keep your energy bills down and your home comfortable.
Winter Cold
If you're willing to be active in managing your home's energy resources, there are many opportunities not only to conserve heat and air-conditioning but also to reduce the burden on your heat and air-conditioning systems.
Though it's 93 million miles away from Earth, our sun puts out some pretty potent energy. It is smart house management to take advantage of that free heat whenever possible. In the winter, opening up shades and drapes on south-facing windows allows sunlight inside the house where it can warm floors, furniture, and furnishings. This is called passive solar heating, and on a sunny day in a well-insulated house it can reduce the number of times your heating system has to activate. One bonus is that during the winter the sun is lower on the horizon, so sunlight penetrates deeper into the house than it does when almost directly overhead in the summer. Therefore, even though the winter sun's rays are less intense, they can still create heat because they cover more surface area in your house.
At night in winter, heavy or insulating shades and drapes drawn over the windows will keep heat inside, acting as both a radiant heat barrier for heat leaving the home and also as insulation over the cold window glazing.
Taking advantage of the sun during the winter can also help lower electricity bills. Though sunlight streaming in through windows is only a heating benefit on the east, south, and west sides of the house, opening shades on the north side of the house in the daytime reduces the need for electrical lighting.
Summer Heat
During the summer you'll want to do the direct opposite -- close shades and drapes in order to keep the warming rays of sunlight out of the house, reducing the load on the cooling system.
Lights Out
Though it's a simple energy-saving step, the concept of turning off lights when leaving a room seems to elude many people who subsequently complain about their utility bills. The fact is, if a light is off, it uses no electricity. So only turn on lights that are necessary for use. It's that easy to save energy.
One urban myth says that turning on a light uses far more energy than it consumes while it is operating. Not so. It is true that when an incandescent or fluorescent lightbulb is first switched on, it requires a brief surge of electricity. But that surge is so short that it doesn't make any practical difference. With fluorescents, the electricity consumed during start-up is equivalent to only a few seconds' worth of running the light. So keep bulbs that aren't being used turned off.
Ceiling Fans
The use of central or room air-conditioning (and the high electrical costs associated with each) can be reduced by deploying a time-honored strategy -- getting the air around you to move. A simple desktop or standing fan that sweeps the room every few seconds makes the air seem cooler by several degrees.
Ceiling fans are a great boon in this regard since they gently move all of the air in a room at once. Ceiling fans can draw up and distribute the cooler air that lies along the floor throughout the entire room.
Whole House Fans
Boon or bane?: Many homes in the United States have "whole house" fans. These large fans, usually mounted in a top-floor ceiling, are turned on during the summer by homeowners who wish to avoid turning on room air units or a central air-conditioning system -- or as an alternative to air conditioning altogether.
The idea behind using a whole house fan is to bring in cooler outside air through open windows while at the same time pushing warmer air through the attic and roof vents. Because of the size of most whole house fans, they are usually effective at accomplishing these tasks. The air movement removes heated air from the attic, which can reduce the heat in the rooms below, and if the incoming air is cooler, then the system does have a cooling effect on the house. Whole house fans can also quickly vent undesirable odors when necessary.
Many people have discovered, however, that air from outside the house often brings with it things they don't want inside, such as humidity, pollen, and dirt. That limits the use of whole house fans at certain times and in some geographical areas, such as states that experience high humidity in the summer.
Saving energy or wasting it?: Many conventional whole house fan installations lack adequate provision for sealing and insulating the opening in the winter. It is often possible to stand in the attic and see light coming upward through the loose-fitting metal louvers under a whole house fan. Those openings allow great amounts of heated air to escape the house and enter an attic in the winter, resulting in energy waste and higher heating bills. Heat from the attic can also be conducted downward through the opening and the louvers during the warm summer months.
Although a whole house fan can save some energy during the summer by prolonging the periods when a room or central air-conditioning system doesn't run, it can waste energy in the winter by allowing warm air to flow upward through the louvers. Draping a length of fiberglass batt insulation over the fan in the winter -- a common practice undertaken to address this issue -- is completely ineffective as either an air-sealing or an insulating measure.
Remediation of whole house fans: Several types of commercially available covers are designed to address the issue of air leaking through whole house fan installations. Some mount on top of the fan in the attic; others are simple covers that attach from the house side of the installation and cut down on air leakage. It is also relatively easy to build a lightweight removable cover of fiberglass insulation board or rigid foam board. Sealing these covers is challenging, however, and that is critical to prevent air infiltration.
An alternative to the large conventional whole house fans are the relatively new smaller fans that have spring-loaded, insulated covers that snap tightly into place when the fan is not being used. While they do not move as much air as the larger models, they are effective if used over a longer period of time.
All in all, while many homeowners like and use whole house fans, they do have some serious drawbacks. It is not unusual to find an abandoned fan in the attic with a patched ceiling below. If you already have a whole house fan in place in your home and intend to put it to use, be sure that the opening is sealed and insulated properly during winter. That opening represents one of the largest and potentially leakiest holes in your entire house. Energy that escapes through those leaks will increase your utility bill substantially.
If you're thinking of installing a whole house fan, at least give the smaller-size units a once-over before you make any final decisions. They use less power, seal and insulate better, are quieter, and the hole they require in the ceiling is smaller than that of a conventional unit.
One room in your house uses a great deal of energy and can put out a lot of heat -- your kitchen. In the next section we'll review tips on how to conserve energy while cooking dinner.
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