Sense Blog

Squeezing More Savings from Your Clothes Dryer

Home clothes dryers are one of the most common appliances found in an average American household, but why haven't they become more energy-efficient? Take a look at the past, present, and future of clothes dryers with some at-home tips for keeping your dryer energy consumption in check.

From the times of the ancient Romans until the mid-1900s, drying clothing has been a time-consuming process. Once excess water was wrung out of clothing, people traditionally hung up or laid their clothes outside to dry.

In the early 1900s, a North Dakotan farmer, frustrated with the ineffectiveness of hanging clothes out to dry in the dead of winter, began investigating more effective ways to dry clothing. J. Ross Moore initially built a shed to hang clothes in and then added a small oven inside to act as a heat source. Moore went further with his concept and developed an oil-heated drum to dry his laundry before eventually selling the idea to a Wisconsin manufacturer. In 1938 the first consumer clothes dryer was produced, the June Day.

Throughout the 1940s, electric dryers remained a luxury item for many Americans. In 1955, only 6 percent of American households had clothes dryers. Clothes dryers increased in popularity through the late fifties and early sixties and by 1963, almost a quarter of all American households owned clothes dryers. Sales continued to grow as the first clothes dryers that vented outside the house were produced in 1958.

Are modern electric clothes dryers efficient?

Very little about the method of drying clothes has changed since the first electric clothes dryer with an exterior vent was offered to the public in 1958. Beyond the sleek and modern exterior design, most clothes dryers are shockingly simple when it comes to the technology “under the hood.”Imagine an oversized hairdryer at full power connected to a big, spinning cylindrical metal drum. When the electric clothes dryer turns on, the dryer is essentially baking the water out of the clothing and exhausting the hot air to the outside. In fact, most upgrades to electric clothes dryers over the past 60 years have amounted to the addition of knobs and dials to control the settings.

One innovation hasn’t delivered on its energy-saving promise. Moisture sensors that shut off the dryer when the laundry is dry are not efficient enough. Testing of these “automatic termination cycles” has shown that many dryers are susceptible to over-drying, with as much as 62% of the energy wasted.

Above: Many residential clothes dryers on the market today provide automatic cycles that are intended to stop when the clothes are dry, as determined by the final remaining moisture content (RMC). However, testing of automatic termination cycles has shown that many dryers are susceptible to over-drying of loads, leading to excess energy consumption. In particular, tests performed using the DOE Test Procedure in Appendix D2 of 10 CFR 430 subpart B have shown that as much as 62% of the energy used in a cycle may be from over-drying.

How much energy do we use drying clothes?

80 percent of all American households have a clothes dryer. With an average energy consumption of 769 kWh per clothes dryer, all those loads of dry laundry add up to over 60 billion kWh per year devoted to electric clothes dryers. That’s almost enough energy to power the entire internet (servers, network equipment, and infrastructure) for a full year and about the equivalent of a year’s worth of total energy output of seven U.S. nuclear power plants.

The NRDC reports that Americans spend about $9 billion per year on energy used to dry their clothes. In total, dryers represent about 6 percent of annual residential electricity consumption and 2 percent of annual residential natural gas consumption.

In fact, electric clothes dryers are the seventh biggest energy consumer in the average American household while clothes washers are eighteenth on the same list.

One of the reasons that clothes dryers rank so high as home energy consumers is their lack of efficiency. The typical dryer today is barely more efficient than a model from the 1980s, and according to the NRDC, the country’s standards for dryer efficiency fall significantly short of versions sold overseas. In fact, the average operating cost for an electric dryer in 2012 was equivalent to the home’s washer, dishwasher and refrigerator combined.

How can I lower the cost of drying clothes?

In the U.S., it costs approximately 45 cents to dry a load of laundry in an electric dryer, based on a 5,600-watt dryer, 40-minute run-time, and a 12-cent-per- kilowatt-hour rate. To find out how much you’re spending on your dryer, track it in the Sense app, which captures the full cost for electric dryers, or use a home appliance calculator to analyze your gas dryer spending.

Gas dryers deliver better savings than electrics when it comes to energy costs. In 2014, a typical household paid more than $100 in annual utility bills to operate an electric dryer compared to $40 for a gas dryer. Over an electric dryer’s lifetime, the total cost for power adds up to $1,500.

Whether you have a gas or electric dryer, here are some tips to reduce your costs:
• Hang clothes to dry when possible.
• Use the delicate setting on your dryer. It will take longer but use less energy.
• Dry multiple loads in sequence so you’re taking advantage of the remaining warmth from the previous load.
• Make sure your washing machine has spun out as much moisture as possible before throwing laundry into the dryer; the washing machine uses energy much more efficiently than the dryer.
• If you replace your dryer, look for the ENERGY STAR label. An ENERGY STAR rated dryer could save you $245 in energy costs over its lifetime. If you have access to natural gas, choose a gas dryer rather than an electric.
• Make sure the dryer vent and lint filter are cleaned out regularly. Clogged vents and filters reduce the dryer’s efficiency and can cause fires.
• If your utility charges variable rates, use your dryer when utility rates are low.
• If you rely on solar power, use your dryer when solar production is high.

Looking to the Future

Now that dryers are included in the ENERGY STAR program, we can expect to see 20% more efficient dryers available to consumers. But the average dryer in the U.S. still uses 40% more energy than counterparts in Europe.

For a glimpse of the next generation in ultrasonic drying, check out the video below from the U.S. Department of Energy. The innovative technology uses vibrations, not heat, to dry fabric and is 3-5 times as efficient as today’s dryers.