Steam appliances are the hottest technology.

Home appliance makers are building up steam.

The trusted technology found in whistling teakettles and surging clothes irons has become a hot thing in washers, dryers, dishwashers and ovens. After all, steam is energy-efficient and can sterilize surfaces such as hospital instruments.

Multipurpose steam cleaners were a popular category at the recent 2011 International Home + Housewares Show in Chicago. Their microfiber pads help remove grime and germs from countertops, tile and floors and also freshen carpet, draperies and upholstery. The devices are even touted as a weapon for killing bedbugs. In less than a minute, they heat ordinary tap water to at least 212 degrees -- the boiling point -- to create steam.

"Many consumers are becoming more educated about environmentally friendly cleaning products," said Lisa Casey Weiss, lifestyle consultant for the International Housewares Association. "And as a result, they have become interested in steam cleaners because they often eliminate the need for harsh chemicals."

So is steam the panacea for cleaning, de-wrinkling and even cooking? It depends.

Portable cleaners

Consumer Reports added the "steam mops" category in 2010. A dozen items that often fall to the floor -- including ketchup, mustard, olive oil, syrup and baby cereal -- were allowed to harden on vinyl floor tiles before testers tackled them with steam mops.

The verdict? Consumer Reports called the H2O Mop ($100) and Eureka Enviro Steamer 313A ($70) "good" and the others "mediocre." The nonprofit, independent testing agency identified a recurring flaw: When there's a large amount of soil, more gets pushed out of the way than picked up by the pad. It also cautions that steam and water could damage wood floors and might void the warranty.

"A $15 squeeze mop proved comparable, if not better, at floor cleaning," the magazine said.

Steam-mop manufacturers have recently addressed concerns through vacuum/steam mop combos that eliminate the need for a mop, bucket, broom and dustpan. As far as potential floor damage, the mops' moisture levels can be adjusted for different types of floors.

"With floors that are a little more delicate, for example ... you can put it on the steam-dusting setting," said Dann Provolo, vice president of marketing for Euro-Pro, maker of Shark steam-cleaning products, which introduced its next generation of Steam-Pocket Mop. "Regardless, a traditional mop with water can leave standing water on a floor, which could damage it. Steam quickly dries."

Portable steam systems with wedge- and cylinder-shaped pads can be used to clean countertops, tile grout, mirrors, windows and upholstery. Steam kills staph, E. coli, mold, mildew and dust mites. A steam unit also can kill bedbugs, with a caveat.

"A steam cleaner should be a tool within a variety of methodologies," Provolo says. "It shouldn't be the entire solution."

Washers and dryers

When Nebraska Furniture Mart salesman Scott Price wanted to replace his top-load washer and dryer in October, he turned to steam.

"I was looking for washing performance, not necessarily energy savings," says Price, who lives in Shawnee, Kan.

But steam washing machines use less power and consume less water than conventional models. A little bit of water can produce a lot of steam, which expands to take up more volume. The front loader uses 15 gallons vs. the 40 gallons his top loader did.

Price chose Whirlpool models that were each $150 more than machines that don't use steam. He likes how the steam cycle on his washer gets out tough stains. He uses the steam dryer to de-wrinkle his clothes.

"I'm the type of person who throws a load of clothes in the dryer overnight," Price says. "So the de-wrinkling cycle touches them up in 10 to 20 minutes in the morning."

The dry clothes look better, he says, when he de-wrinkles one item at a time. Price's observations are in line with Consumer Reports' test results.

"We found that with washers, the steam does improve the performance somewhat," said Emilio Gonzalez, senior program leader in the appliance division at Consumer Reports. "With dryers, it's mixed. They're great at alleviating odor buildup, so you can freshen up clothes. ... But they're not always great with wrinkles."

Steam washers and dryers start at $600 each.

Dishwashers

Conventional dishwashers produce steam in the drying cycle when leftover water is converted to vapor. But steam dishwashers use steam in the washing phases.

"One of the main reasons you're seeing more steam dishwashers is because detergent manufacturers have eliminated phosphates," says Stephen Wright, appliance manager at Nebraska Furniture Mart. "So [conventional] dishwashers aren't as good at breaking up debris, especially the caked-on stuff."

Steam dishwashers don't exclusively use steam for cleaning, but they can employ it on different cycles. For example, GE steam dishwashers have pre-wash cycles (steam baths) that loosen food before normal wash cycles, eliminating the need to manually rinse dishes, which wastes water.

Consumer Reports is lukewarm on steam dishwashers. They found the addition of steam does make dishes cleaner, but only a little bit. A downside: They take a lot longer to get through a wash cycle, adding as much as 45 minutes. The upsides: They're quiet and energy-efficient.

Steam dishwashers start at $600.

Ovens and steamers

Portfolio Kitchen & Home in Kansas City knows that technology is steaming up in the heart of the home -- and on "Oprah," where actress Gwyneth Paltrow said the steamer was her favorite kitchen tool. The design center demonstrates its Gaggenau steam-convection combination oven and in-counter steamer.

"It's a way to make nutritional food that tastes like it came from a restaurant," said Portfolio owner Geri Higgins. "You don't have to add butter or sauce to it to make it more moist or flavorful."

The steamer and the oven are self-cleaning; condensation needs to be wiped up after cooking. For an integrated countertop steamer, a plumber hooks up water and drainage lines. Because calcium can sometimes clog water lines, many models contain water cartridges. Ovens come with detachable water reservoirs and don't typically require plumbing.

Steam-combination ovens cook fast, too. A 14-pound turkey takes 90 minutes.

Some opt to reheat food with steam instead of using a microwave. Leftover pizza, for example, tastes like it's fresh out of the oven.

"You're starting to see steam ovens as a second oven above a conventional one," Higgins says. "Instead of a microwave."

Steamers integrated into a surface start at $1,000 and require plumbing. Oven prices start at $2,000 -- and go way up from there.

COOKING WITH STEAM
STEAMER
Price: Steamers integrated into the counter or cooktop start at $1,000 and require plumbing. Gaggenau steamerVK411610 is $2,899.
Who'd like a steamer: At-home cooks who want fresh meals fast.
How it works: The steamer is integrated into the countertop and includes a drainage pipe underneath. It differs from an electric small-appliance steamer in that it's built in and can be used to boil water for pasta.
OVEN
Price: They start at $2,000 in brands such as Kenmore, KitchenAid, Miele and Viking. Thermador recently introduced a new steam-combination oven for about $3,200. The Gaggenau electric steam oven starts at $6,349.
Who'd like a steam oven: Someone who wants to cook healthy food fast, and bread bakers (combination ovens use steam mist for good crust).
How it works: Most steam ovens and combination ovens (in microwave and conventional sizes) come equipped with a detachable reservoir to be filled with water to begin the baking process. Trays of different foods can be cooked simultaneously without flavor transfer.
OVEN CLEANING
Steam-cleaning cycles are becoming more common in conventional ovens.
"We've seen that consumers are wary of four-hour plus cleaning cycles that make their oven really, really hot and their house smell," says Michael DiLauro, home product specialist at Consumer Reports.
The steam-cleaning function is more for touch-up cleaning instead of baked-on cleaning. "It's not something that consumers are paying more for," DiLauro says. "More ovens are coming out with them."
Who'd like it: Kitchen neat-freaks.
How it works: Most models work by pouring 10 ounces of distilled or filtered water into the bottom of the oven for the steam-clean function, which takes about 20 minutes. Remaining water in the bottom of the oven can be wiped away.
TACKLING THE BATHROOM
Steam cleaners aren't just for floors and upholstery. Handy devices have entered the bath to help tackle tile, mirrors, counters and light fixtures. Anything but the toilet bowl. Among them is the Oreck Steam-It All-Purpose Steamwand, $169, www.oreck.com, which comes with six attachments and two machine-washable microfiber pads. Also use to clean floors and freshen upholstery.
Who'd like it: Chemical-leery consumers who want to fight germs.
How it works: The water in the device heats up in 30 seconds and can be used for 20 or so minutes before a refill.
CARING FOR CLOTHES
De-wrinkle garments right on the hanger with a hand-held system. You can use it to freshen fabrics, too, which limits the use of soaps and dry-cleaning chemicals, allowing fabrics to last longer. Just be sure your clothes are colorfast, otherwise a steamer can fade them. Among them is the Shark Press & Refresh with vertical ironing pad, $99.99, www.GoPressandRefresh.com
Who'd like it: The iron-challenged, and fashionistas.
How it works: Holding the steam trigger, you move the small device up and down. A vertical hanging pad allows you to press garments on the hanger.
LAUNDRY
Price: Steam washers and dryers start at $600 each. The GE Profile Frontload Steam Washer with Overnight Ready Cycle can wash and dry clothes in the same machine. Among these is the new LG Studio Series SteamWasher, $1,889, and SteamDryer, $1,759
Who'd like a steam washer: Parents of young athletes, allergy sufferers and those who want to get out tough stains.
How it works: Steam generators with nozzles are dedicated to releasing steam or heating water in the tub. Steam can be used to pre-treat stains and during the wash cycle to more effectively dissolve detergent.
Who'd like a steam dryer: Frequent event goers or those around cigarette smoke.
How it works: Steam penetrates and moistens clothes deeply, which creates a softening effect that reduces wrinkles. Steam's high temperature sanitizes clothes, helping to eliminate odors.
DISHES
Price: Steam dishwashers start at $600. Among them is the GE Profile PDWT380RSS, $950.
Who'd like it: Eco-minded consumers who don't want to pre-rinse and/or those who frequently use fine china.
How it works: Nozzles release steam or heat water in the tub into steam. They also have conventional functions.