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.
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.
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.
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.
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.