How to get the most clean laundry for the least money and energy

If your laundry appliances are more than a few years old, an energy efficient washer and dryer might be worth investing in. Recent improvements in efficiency, especially on the clothes washer side, can translate into substantial savings on both the electricity used by the washer and on the energy used to heat hot water.

Most North Americans use top-loading washers. The agitators in these washers can be tough on clothes, causing abrasion and wearing the clothes out faster. The vertical layout means the tub has to be filled at least to the level of the laundry in it, using more (potentially hot) water. And the design of these washers means that they are typically limited to a fairly modest spin cycle, so less water is extracted before you pop the clothes into the dryer. That translates into longer drying times and more energy used for drying.

On the dryer front, the main factor affecting energy efficiency is whether you use a natural gas or electric dryer. Even though the heating element in an electric dryer is 100% energy efficient – meaning it converts 100% of the electricity it consumes into heat – when you factor in the entire life-cycle efficiency of electricity, the cost per unit of heat output is usually higher with electricity than with natural gas, and in many cases you may be causing more greenhouse gas emissions with an electric dryer. The same applies for an electric hot water tank to heat the water for your washer, as compared to a natural gas tank.

Electric vs natural gas heat

As I explain in Natural gas advantages, when you use electricity to produce heat in your home (for whatever purpose, including drying clothes or heating water for laundry), you are converting 100% of the electricity to heat, but if the electricity originated from a fossil fuel, only a small proportion of the original fossil fuel heat ever makes it to your house. For instance, electricity generated from a coal-powered generating station only converts about 35% of the energy in the coal into electricity; the rest is waste heat. (If we ever get carbon capture working for coal-fired plants, where the emitted CO2 is pressurized and pumped into the ground, that efficiency could go even lower, since it will take energy to pressurize the CO2 and pump it into storage!).

There’s also a 6-9% transmission loss getting the electricity to you, which means that the 35% generating-station efficiency of coal is now down to about 32%. And for a given heat output, coal releases considerably more CO2 than natural gas: in 1999, for example, coal fired plants in the US produced on average 2.095 pounds of CO2 per kilowatt hour of electricity generated, while natural gas fired generating stations produced 1.321 pounds of CO2 per kilowatt hour.

How does all this relate to an energy efficient washer and dryer? Well, you can’t of course run a dryer or a hot water heater on coal, but you can run both on natural gas. And a natural gas dryer or hot water heater can convert much more than 32% of the original thermal energy into heat to dry your clothes or heat your water. This is the main reason why using natural gas heat for your laundry usually makes more sense economically, and depending on where your electricity comes from, may also make more sense environmentally. Of course, if you don’t have a natural gas line to your house, electricity may be a better bet than a propane tank from a cost point of view.

Which uses more energy – washer or dryer?

Whether you own an energy efficient washer and dryer, or older or less efficient models of one or the other, which uses more energy? The answer is, it depends.

According to the Canadian Office of Energy Efficiency, top-loading clothes washers made in or before 1990 use on average 1218 kilowatt hours per year; those made in 2003 use on average 887 kilowatt hours per year; and ENERGY STAR qualified washers made in 2003 use on average 296 kilowatt hours per year. So upgrading to a recent-vintage ENERGY STAR qualified model will likely save you several hundred kilowatt hours per year, which translates into something around $30-100 per year in savings depending on how inefficient your older model was, how much laundry you do, and how much you pay per kwh of electricity.

Dryers, meanwhile, used on average 1103 kilowatt hours per year in 1990, while those in 2003 used only 914 kilowatt hours per year.

These energy ratings factor in both the energy used for the electricity to run the appliance, and the energy used for any required heat, such as the heating of hot water for the washer and the heating of air for the dryer. The ratings make this assumption to make comparisons easier between gas and electric dryers and to factor in the total energy cost of washers (including water heating costs).

From the above numbers you can see that if you have an old washer and dryer, your washer probably uses more electricity, and your best bet is to replace just the washer, with a front loading model, if you can only afford to buy one of the two. Of course, if you can afford both, an energy efficient washer and dryer will save you even more money on energy.

In fact, if you can’t afford to buy both an energy efficient washer and dryer, there’s another excellent reason to replace the washer first. If you have an older top-loading model and you replace it with a new ENERGY STAR front loading model, you not only reduce the energy costs and water use for the wash cycle, but the spin cycle will get more water out of the clothes before you pop them in the dryer, which means you’ll use less energy on the dry cycle even with an older washer.

You might be wondering whether there are ENERGY STAR dryers as well. It turns out there aren’t, because (the ENERGY STAR folks argue) there’s not that much difference in energy consumption between the worst and the best standard dryers; most of the energy consumption of a dryer is just the heat used to dry the clothes, and heat is heat. However, there is a new type of dryer called a condensing dryer that can give you substantial savings in electricity/natural gas use: these dryers can use as little as 386 kilowatt hours per year (such as the models made by Miele), while traditional dryers use as much as 966 kilowatt hours (Amana, Brada, Samsung).

Little things add up

The next time you throw a load of laundry into your dryer, think about the environmental implications of the way we dry our clothes. Did you know, for example, that in Canada alone, people use the equivalent of 7.2 billion kilowatt hours per year of electricity to dry their clothes in dryers? For the US, given a population nearly ten times as large, the total energy consumption of dryers would be in the order of 70 billion kilowatt hours.

Considering that about 50% of US electricity is generated from coal, and that more than 90% of the dryers in the US are electric, that works out to at least 15 million tons of coal being burned to run US dryers. If every American switched to line drying for just one out of every seven loads of laundry, that would reduce energy demand by a gigawatt hour – or one billion kilowatt hours. That would actually make a noticeable dent in our greenhouse gas emissions.

Space saving features

Another advantage of an energy efficient washer and dryer combination is that, when you buy a an energy efficient washer and dryer in the same product line (with the washer being, of course, a front loader), you can often stack the energy efficient washer and dryer together (with the dryer on top), since the washer controls are all at the front of the unit. Buying a stackable energy efficient washer and dryer together translates into significant space savings, if your laundry room is small or you use a bathroom or closet to store your laundry appliances.

You can even buy some units that are energy efficient washer and dryer combos – they wash and dry in one unit. Such units are often compact, meaning they can fit easily in a closet or under an open kitchen shelf in a small apartment, and they are usually movable as well. Combination energy efficient washer and dryer units do not require venting, as they use a condensation cycle for drying (where cold water from the tap is sprayed through the exhaust air to condense moisture out of it). These units can even be set up to do your wash and dry in one step – throw the clothes in the unit, and come back a few hours later to a clean, dry load of laundry.

A friend of mine installed a combination washer/dryer from Bosch in a rental apartment he owned, since he wanted to provide the tenant with laundry appliances in the apartment but there wasn’t space for a washer and dryer set. The combination unit worked reasonably well but the small capacity of the unit, combined with the long cycle time (about 4-6 hours from start of wash cycle to end of dry cycle) made this unit frustrating for his tenants. If you think about the typical process of doing laundry, if you separate out whites, lights, and darks into three loads, you can be washing one load while the previous load dries; not so with a combination unit. Of course, if you’re only doing one load of combined whites and colors a week (e.g. for a one-person apartment) this benefit doesn’t apply.

Energy saving laundry tips – whatever your appliances

Upgrading to an energy efficient washer and dryer will definitely help you cut down on household energy use, but there are some things you can do to cut energy use regardless of the laundry appliances at your disposal. For example:

  • Always use cold water wash. Your clothes will last longer and you’ll use less energy. Remember that hot water is the biggest energy use involved in doing laundry. One big reason an energy efficient washer and dryer save you money is that efficient front loading washers use a lot less water than top-loaders. But using cold water saves even more.
  • Dry your clothes on a clothesline or laundry rack. You can do this outdoors in sunny weather – even in the winter. Your clothes may get as hard as a board while they’re drying, but once you bring them in they’ll soften up. You can also dry your clothes indoors; I use both a laundry rack and a retractable clothes line that stretches across my basement, from one corner of the work room to the diagonally opposite corner of the rec room, which gives me enough space to hang up an entire load of sheets or shirts and pants. You can use the line first, then finish off in the dryer if you want to soften the clothes or if they take too long to air-dry.
  • Don’t do laundry. Don’t throw clothes in the hamper just because that’s easier than folding them and putting them away – only wash clothes that really need washing. And especially watch for the Jevons paradox – where investing in efficiency leads to greater energy use – just because you buy an energy efficient washer and dryer doesn’t mean you can suddenly start being wasteful! In my family, the Don’t do laundry rule usually means any socks or underwear worn for a day, and for shirts, pants, and sweatshirts, anything that is visibly dirty or stained or no longer smells clean. Not only will you save time and energy for yourself (or whoever does your laundry) but you’ll reduce the wear and tear on your clothes.
  • Clean your dryer lint filter before every load. The more lint builds up in the filter, the harder the dryer fan has to work to pump air through the filter.
  • Get a dryer vent seal to prevent cold air from leaking down into the dryer (especially a dryer stored in the basement, since cold air falls). If the inside of your dryer feels really cold when you open it in winter to put in a load, you definitely need a dryer vent seal to keep the cold air out.

More tips on washers and dryers

If you’d like more information on finding an energy efficient washer and dryer or how to get the most out of the appliances you already have, see my separate pages on energy saving washers and energy efficient dryers. And if you’re thinking of trying dryer balls as a way to make your dryer more efficient, think again, as I explain in my dryer balls review.

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