In Consumer Reports' recent report on programmable thermostats, the Nest Learning Thermostat earned a spot on our recommended list, thanks to its clear display, relative programming ease, and Wi-Fi capability, which allows you to control the device from a computer or smart phone. But several programmable thermostats fared better overall in our Ratings. The second-generation Nest, which launches today, comes with several design enhancements and the promise of improved control and compatibility.

In a milestone in energy-savings, one million homes have been weatherized since 2009 as part of the Energy Department's Weatherization Assistance Program. Financed by the American Recovery and Reinvestment Act, the program helps lower-income households, which studies show spend significantly more of their total income on energy bills than other households. But homeowners who don't qualify for the program can use the same techniques to seal the leaks in their own homes and reap the rewards.

How do I conduct my own energy audit? Is installing a tankless water heater worth it? How do I know if I have enough insulation? Those were just some of the questions asked in today's Twitter #askEnergy chat sponsored by the Department of Energy. Clearly, with the arrival of cooler temperatures, saving energy and money is on the minds of consumers. And the DOE advised, much as Consumer Reports always does, that the best place to start is by sealing the leaks in your home.

Programmable thermostats can lower energy bills by roughly $180 a year, yet only half of thermostats installed in today's homes are programmed to lower temperatures when the house is unoccupied or at night, according to a study funded by the Department of Energy. The reason, says other studies, is that people find programmable thermostats too hard to use. And in Consumer Reports latest tests of 30 energy-saving thermostats, we did find some that were so difficult to set that you might give up in frustration. Fortunately, some others were simple to adjust.

Electric space heaters are a cheap way to chase away the chills—and they don't come much cheaper than the $25 Optimus H-5210 sold at major retailers like Amazon, Sears, and Walmart. But it was the only electric heater in our tests of 19 models that set our test cloth on fire. We contacted Optimus, and test results it sent us also showed a potential safety problem with this model. It claims to have fixed the problem on 2012 models. But we bought our heaters, 2011 models, in early summer, and there is no way to tell the model year from the box.

Isaac in all its guises—hurricane, tropical storm, tropical depression—dropped a lot of rain on residents of the Gulf Coast leaving behind a soggy mess. The next threat for affected homeowners is mold, which can ruin home furnishings and pose problems for residents with allergies, asthma, and compromised immune systems. To keep it in check, homeowners should attack the problem within 24 to 48 hours.

The Energy Department is looking to a new generation of engineers and entrepreneurs to help solve the nation's energy challenges. To that end, it awarded first prize to a team of students at the University of Maryland who redesigned the room air conditioner as part of a DOE appliance challenge. The completed prototype reduced energy use by 30 percent compared to a typical unit, which would result in substantial savings for homeowners.

With much of the country still under a blanket of sweltering heat, chances are you still have your dehumidifier running full tilt. But dry, cool air will be here before you know it, and retailers have already stocked up on humidifiers. Consumer Reports recently wrapped up testing of nearly 30 models from brands like Crane, Essick, Hunter and Vicks. About a dozen made our winner's list—not a bad percentage as product categories go—though we also found several models with poor performance and added costs.

The maker of EdenPure heaters has been told to discontinue its claims that the portable heaters are safer, superior and save more than other heaters. Suarez Corp, the manufacturer, can continue to boast that the heaters are "made in the U.S.A." after a review by the Electronic Retailing Self-Regulation program. Consumer Reports recently included an EdenPure model in its tests of portable heaters but it didn't make the list of eight top picks.

Sears, Roebuck and Co. and Kmart Corporation recalled 795,000 Kenmore dehumidifiers because the units can overheat, smoke, melt and catch fire, posing a fire and burn hazard. Sears has received 107 reports of incidents, including three smoke inhalation injuries and more than $7 million in property damage.

Nearly half the money you spend on home energy goes to heating and cooling. For the average household that's about $1,100 a year. A programmable thermostat can save you money by automatically reducing heating or cooling when you need it least. The thermostat has to be properly set, of course, and our latest tests of 30 models reveal that many are now much easier to use.

First there was Siri, now there's Iris. While Siri can find a burger joint or hotel for iPhone users, Iris can help anyone with a smart phone, computer or tablet monitor their home from afar. Iris, a cloud-based home management system launched by Lowe's, can alert you when your child arrives home from school or enable you to remotely control your thermostat, lights and other home electronics.

It's not quite the Olympics, but the Battle of the Buildings sponsored by the Environmental Protection Agency kicked off today with nearly 3,300 excited competitors vying for the prize of the biggest energy loser. More of a marathon than a sprint, the contest continues until next April when a winner will be announced. In the meantime, you can take some tips from last year's top 10 and put your home on an energy diet.

As the summer heat continues unabated, it's a good time to make sure you're getting the most out of your air conditioner and dehumidifier. One easy way is to clean the filters. If you haven't done so since summer began, then this chore is long overdue. The improved performance of your appliances will make you glad you made the effort.

It seems like a no-brainer. An electric fan will cool you off in a heat wave, right? But researchers in England say there's no hard evidence that fans are effective—or safe—ways to beat the heat.