Home expert Q&A

Darker shingles get hotter than lighter shingles, all things being equal, which might increase your cooling needs. Other factors, such as the shingle's surface, are important, too. Energy Star roofing products can reduce your peak cooling needs by up to 15 percent, federal officials say.

The two batteries for my cordless drill are dying. Do replacements hold a charge as well as the originals?

Based on years of cordless-drill testing, during which our experts have replaced many batteries due to the tough nature of our tests, we've determined that replacement batteries from the manufacturer can hold a charge and work just as well as the originals. But you might consider replacing the entire tool. Several worthwhile models in our Ratings (available to subscribers) will cost you less than or about the same price as two replacement batteries.

Can I safely use an oil-filled electric heater in a two-car garage where I don't store paint, gas, or solvents?

No. Other items in a garage are also sources of flammable vapors, including gas-powered lawn gear. Any heater's controls can generate an arc or spark that could cause an explosion or start a fire if surrounded by the right concentration of flammable vapors.

How is it possible that a front-loading washing machine with a 70- to 90-minute normal wash cycle is more efficient than a top-loader with a 35-minute normal cycle?

The biggest energy advantage of front-loaders is their ability to extract far more water from clothes than top-loaders can. That means your dryer doesn't have to run as long. Even with their longer cycle times, front-loaders use less water overall—about 10 gallons less per load on average. And since the smaller amount of water used by a front-loader concentrates laundry detergent, cleaning performance is typically boosted.

Does preparing food in a slow cooker destroy nutrients?

For many foods, any cooking method that involves heat will destroy some vitamins and minerals. In theory, slow cooking would destroy more nutrients than most methods because it exposes food to heat and liquid for hours at a time. But some of those losses may be recouped because you'd probably consume the cooking liquid with your meal and not discard it as you would after boiling or blanching.