Is it possible to keep the house cool without air conditioning?

Yes, that's fairly easily done in Vermont where few days are hot enough to require air conditioning. Here are some tips:

• In the cooler hours of the evening and early morning, open your windows. Use a window fan, blowing toward the outside, to pull cool air in through other windows and to push hot air out.
• During the day, close coverings on the windows that get direct sunlight. On hottest days, keep the windows closed. External awnings and trees also provide shade for windows.
• Delay heat- and/or humidity- producing activities, such as dishwashing, baking, showering, or doing laundry, until the cooler evening hours. Always use a bath fan when showering.
• Use an exhaust fan, directly to the outdoors, to blow hot air out of your kitchen while cooking. The savings in your cooling costs far outweigh the electricity use of the fan.
• Caulk around your window frames and exterior doorframes and use weather stripping on exterior doors.
• Seal any holes and gaps between the attic and your living space and see that you have a minimum of 12 inches of insulation in the attic. Hiring a professional is the most effective approach to air sealing and insulation. You can find a Home Performance with ENERGY STAR® certified contractor at www.efficiencyvermont.com/homeperformance.
• Use compact fluorescent light bulbs (CFLs). Incandescent light bulbs use only 10% of their energy to produce light. The rest is released as heat. CFLs produce only a fraction of the heat and don't waste electricity.
• Be sure that the clothes dryer is vented to the outdoors. In addition to reducing heat in the summer, this is important year-round for indoor air quality and for preventing damage to your home from moisture, mold and mildew.

I've had my 12,000 Btu window air conditioner for six years. I want to save electricity but the unit works fine, so is it worth it to replace it with an ENERGY STAR model?

In your situation, it's best to wait until the old air conditioner fails. Here's why: The decision has to do with whether or not the energy savings from a new unit would pay for your purchase in a reasonable time. Savings depend on the age of the air conditioner, its size, and how much you use it. If your current unit had been manufactured before October of 2000, replacement would be a better idea, because a new ENERGY STAR qualified air conditioner is 25% more efficient than those older models.

But yours is newer. Today's ENERGY STAR qualified models are 10% more efficient than air conditioners made since 2000. So, your savings wouldn't be large enough to justify replacement of a functioning unit.

Another factor that makes waiting a good idea is the simple fact that we're in Vermont. Few days in a typical Vermont summer are hot enough for air conditioning, so let's estimate that your air conditioner is on for only 100 hours per month for three months. Compared to most places in the U.S., that's a very short season of use for an air conditioner! Based on that usage, your annual air conditioning electricity bill, for your size unit, would be about $48. That's about $5 more than a comparable ENERGY STAR qualified unit would cost to operate.

So, unless you use your air conditioner a great deal more than we've assumed, you can see why it's logical, financially, to wait to buy a new unit. Once your old air conditioner fails, it definitely will be worthwhile to buy an ENERGY STAR qualified model.

I've been hearing a lot about replacing incandescent light bulbs with CFLs, to save energy. I want to do it, but it feels wasteful to get rid of perfectly good light bulbs. I think that you should advice people to put in CFLs only after incandescents wear out. If I'm wrong about that, please explain why.

We know what you mean; it goes against a Vermonter's grain to toss something that's useful. But, compared to CFLs, incandescents aren't actually useful. Incandescent bulbs demand as much as 75% more energy and burn out as much as 10-times faster than CFLs. So the wasteful option, it turns out, is to keep the functioning incandescents.

You can look at it this way: You probably paid about 60 cents for the 60-watt incandescent in the lamp beside your favorite armchair. Less than two months after replacing it with a CFL, you can make those 60 cents back in energy savings. If you multiply that savings by every light socket in the house, for all the years that CFLs last, the savings are significant. So, throwing out a functioning incandescent actually saves me money.

If you're concerned about the environmental impact of adding more trash to the landfill, keep in mind that incandescents damage Vermont's environment as long as they're lit. That's because they demand more electricity from power plants that, in turn, pollute the air. Bottom line: Hanging onto old incandescents costs you, and the environment, day after day.

When I have to change from analog to digital TV next year, I don't want to run up my electric bill by going about it the wrong way. Can you tell me which uses less electricity: A converter for my 28-inch, cathode-ray tube TV or a new, flat-screen TV that's digital-ready?  

Lots of people are wondering the same thing. Typically, you'll use less energy adding a converter to a cathode-ray tube TV than you will by using a flat-screen, digital, high-definition TV (HDTV) of the same size as the CRT.

Here's why: You can purchase an ENERGY STAR® qualified converter that operates on less than 8 watts and uses only about 1 watt in sleep mode. If you watch four hours of TV per day, use of this converter will cost you about $4 dollars annually. But if you swapped a TV smaller than 40 inches, as yours is, to an HDTV of the same size, the new set would cost you, annually, at least $15 more than the current cost of operating your old TV. If you upgraded to a bigger HDTV, the operating cost would go up substantially with size.

Size is the most important factor when it comes to the energy demands of flat-screen TVs. If you do decide to get a new TV, look for the ENERGY STAR label for energy savings.

I've got an electric water heater and I'm thinking of switching to an electric instantaneous hot water heater. Would that reduce my electric bill?

Probably not.  It takes the same amount of electricity to heat a given amount of water, regardless of which technology you use. It's possible for a tank-style water heater to use a little bit more energy if the tank isn't insulated and if it's not in a well-insulated part of your home. But the cure for that isn't an instantaneous water heater; it's insulation.

Insulate both the hot and cold pipes within three feet of the tank. Pipe insulation, available at hardware stores, comes in flexible, closed-cell foam sleeves that are usually packaged in three-foot lengths. Choose the right size for your pipe diameter. These slip-on sleeves are easy to install and cover the entire pipe surface, even when bent around corners. Use electric tape over the places where the sleeve ends meet.

Also, keep in mind the fact that a tank-style water heater generally can provide all the hot water you would need at one time. Instantaneous water heaters provide only as much hot water as can be heated on a continuous basis, because they have no reservoir.

We just bought a house with a pool. How do we lower the cost of running the pool pump?

The simplest thing you can do is to run the pump only as long as is needed. To determine that timing, you'll need to experiment. Start by running the pump for eight hours per day. If the pool stays clear, run the pump less often. If it starts to get cloudy, run it a bit more each day until it clears. You may find that different run times are required at different times of the year. Use a timer that is rated for the size pump you have.

Another way you can save on operation costs is to match the size of the pump to the needs of your pool. When it comes time to replace the pump or the pump motor, get only the horsepower you need and look for a two-speed or variable-speed pump motor. A pool supplier can help you match the pump to the piping and pool that you have. If you end up downsizing the pump, talk to your supplier about using a larger filter and piping to reduce the water-flow resistance in the system. For the most efficient operation, keep intakes and drains clean, and backwash regularly.

I have a lot of portable devices that need charging. Is it true that a rechargers uses energy as long as it's plugged into the wall, even when a portable device isn't hooked up to it?

Yes. Idle, plugged-in chargers are a contributor to your home's “phantom load”. Phantom load is the electricity that many of today's electronics use when off but plugged-in. These devices include any equipment that has a standby light or a clock, such as most microwaves, DVD players, televisions, and more. They also include plugged-in chargers that aren't actively in use. The total phantom load in a typical electronically-equipped house can be on the order of a constant 100 watts. Over the course of a year, that adds up to about $116 dollars in electricity costs.

An easy way to eliminate this cost is to plug numerous pieces of equipment into a power strip/surge protector. When you're through using the equipment, you can switch off the strip rather than unplug individual devices.

My dad noticed that I switched over a bunch of lamps in my house to CFLs. He said it was a bad idea because trash haulers and dumps won't take them. Is it true that there's nowhere to dispose of CFLs?

No. While your dad is right that you can't toss compact fluorescent light bulbs (CFLs) in the household trash or household recycling, there are plenty of places in Vermont where you can dispose of CFLs. You can bring unbroken bulbs to many hardware stores for free recycling. You also can take broken and unbroken CFLs to many waste-disposal facilities. To find a participating location near you, visit www.newbulbintown.com.

I teach high school science, and my students are curious about compact fluorescent light bulbs. I hope you can help me out with these two questions about the basic functions of these bulbs. Why are they spiral? What is the function of the base?

You can start by directing your students' attention to the familiar overhead tubes that most likely light your classroom. They should be able to identify these as fluorescent lights. You can explain that the more light we want from a fluorescent light, the greater a tube's surface area needs to be. If your class then takes a look at a compact fluorescent light (CFL), they'll see that this, too, is a tube. CFLs have simply been shaped into a spiral so that they'll take up the same amount of space as a traditional Edison bulb without losing the surface area needed to produce good quality, bright light. Thus the term 'compact fluorescent'.

As for the base of the CFL, it's called a ballast. This is an electronic device that provides the voltage necessary to turn on the light and then regulates the voltage to allow the CFL to operate with the highest efficiency. Ballasts serve the same purpose in those overhead fluorescent lights in your classroom, but they're part of the fixture, not of the tube. If your students are interested in learning more about energy efficiency, you can arrange for a speaker from Vermont Energy Education Program to conduct a hands-on workshop in your classroom. Visit www.veep.org.

How much electricity does an outdoor hot tub use?

The average-size hot tub generally uses about 300 kilowatt-hours per month. The exact usage depends on the size of the tub, the temperature difference between the water and the outside air, insulation levels around the hot tub and how often the tube is used. Operating costs in the winter will be higher because the hot tub will lose heat quicker and require the heater to run longer. You can help save electricity by keeping the temperature lower when the tub is not in use and making sure it is well insulated.

What's my best energy-saving refrigerator choice?  Are top-freezer models most efficient?

The easiest way to know you've found an energy-saving refrigerator is to look for an ENERGY STAR® qualified model. These models save energy by using high-efficiency compressors, improved insulation and more precise temperature and defrost mechanisms. Keep in mind that larger models use more energy and that some features increase energy use as well. For example, automatic icemakers, through-the-door dispensers and "anti-sweat" heaters (sometimes called the “summer" or "humidity control" switch) consume more power.

To answer your second question, top or bottom freezer models tend to be more efficient than side-by-side units. Regardless of the style you choose, you'll get better energy performance if you keep a fridge full, clean the condenser coils at least once a year, limit the frequency and length of open-door times, and keep door seals in good repair.

Do energy-efficient dehumidifiers exist?

Yes. Look for an ENERGY STAR® qualified dehumidifier. It removes the same amount of moisture as a similarly-sized standard unit, but uses 10 to 20% less energy. These units save energy because they have more-efficient refrigeration coils, compressors, and fans than conventional models do.

But there are ways to reduce or eliminate excess moisture without adding dehumidifier costs to your electric bill. Click here to learn how to fix or prevent household moisture problems without a dehumidifier. If problems persist, go here to identify the best size dehumidifier for the conditions in your home.

You can get a $25 rebate for an ENERGY STAR® qualified dehumidifier until August 31, 2008. Get a rebate coupon. Find a store.

I've heard there's a way of testing breakers to figure out what's causing high electric bills. Can you explain that?

Sure. Sometimes you can find a mysterious high-use culprit by isolating the electrical circuit it's on. This is best done with two people: one standing by the electric meter, the other standing inside at the electrical breaker box. If you're not in shouting distance to each other, use cell phones to communicate.

Start by watching the spinning disk on the electric meter and noting how long it takes for it to spin around one time. There is usually a black mark on the disk to help you. The person at the breaker box can then turn off and on breakers, one by one, as the other person watches the spinning disk. You may notice that turning off one particular breaker will cause the meter to spin more slowly. Make a note of the breakers that have the greatest effect on the speed of the spinning disk and determine what appliances are on those circuits. You can then borrow a meter from Efficiency Vermont (888-921-5990) to find the appliance that uses the most electricity. Plug an appliance into the meter and the meter into the wall and you should be able to find your high-use culprit.

If I put a compact fluorescent light bulb (CFL) in a fixture that places the bulb in an upside-down position, will the bulb last as long as one that's upright? Also, if a CFL is in a ceiling dome light with little airflow, will the longevity of the bulb or quality of light be less?

In both cases, light quality will be unaffected but longevity may indeed be somewhat shortened. While it's tough to know exactly how much shorter the life of an upside down or enclosed CFL is, you can be confident that a CFL will last longer than an incandescent light bulb in any fixture. CFLs in ideal conditions last up to 10 times longer than incandescents. So, no matter where you place CFLs, you won't be reducing their life to the level of an incandescent.

I've heard that it takes less energy to heat up a cool house than to keep it warm constantly. Is this true about air conditioning too?

Yes. You can look at this way: If you were planning on pasta for dinner, you wouldn't keep a pot of water boiling all day. So, turn the air conditioning off while you're out. If you have central air conditioning, you can use a programmable thermostat to automatically turn up the temperature at the time you normally leave the house, and turn it down in time to have your house cool for you when you get home. Some newer window units also have programmable thermostats. If you have a window model without this feature, you can use a timer to turn the air on and off but the timer must be rated for use with a window air conditioner. A timer that you use for lights is not rated for this use.

When we reopened our camp house in the spring, we started wondering if we'd been wasting electricity over the winter by keeping our electric water heater and fridge running. Can you tell me how to safely lower the energy the camp uses after we close it in the fall?

Absolutely. In fact, if you're willing to make some careful preparations, you can do more than lower your empty camp's electricity use; you can eliminate it. It's a matter of winterizing the entire house, including the water heater, and carefully following proper methods to drain any device that uses water. It's best to find a trusted contractor in the area to complete this for you, as mistakes could lead to burst pipes, cracked toilets or busted water heaters.

Prepping the refrigerator is simple. Empty and clean the fridge, unplug it and prop the door open to prevent smells from developing. When all this is done, turn off the main power at the breaker box, and head home knowing that you've properly tucked in your camp for its winter hibernation.