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Going for Efficiency with Washers and Dryers

Of all the appliances in your house, the odds are pretty good that your dryer consumes the most energy. IGS estimates that the average household spends more money on energy and water for their washer and dryer than they spend on utilities for any other appliance in the house. Grist points out that while all other appliances have gotten nearly twice as efficient since 1981, dryers remain energy hogs. In fact, your dryer is likely to consume as much electricity as all your other appliances combined. The effect may be even greater if you go out of your way to buy energy efficient appliances, like dishwashers with an air dry option and energy star rated refrigerators, but keep using your old dryer.

Source: Grist

When we bought our old house (1941 vintage), it came with an old washer and dryer. I don’t think that they are from 1981, but they probably aren’t much younger. The washer drained into a sink, and the dryer vented into an old sagging flexible hose. At one point, the sink got clogged, and I was appalled to discover just how much water the washing machine was using. It filled up both sides of the sink and then overflowed onto the floor – after just one cycle! It was clearly time to buy a new set of machines, but I delayed my purchase because a visiting plumber took a look and told me that bringing the drain pipe up to code (1.5 inch to 2 inches) would cost around $3,000, plus tax, which would be required for professional installation.. 

After watching this thing waste water and electricity for another few months, I got fed up and started researching whether I could set up a new washer myself and just have it drain into the sink like the existing one. I found a clip from This Old House that showed how to get the job done, and since a new front-loading washing machine would consume far less water than my existing lake-drainer, I wasn’t worried about the sink overflowing.

I spent several evenings researching my options. Here is what I found:

  1. New front loading washers use less than half as much water as top-loading models. In addition, they spin up to 1,300 RPMs at the end of the cycle to leave your clothes less damp. This will cut down on the time and energy that your dryer needs to run. Lastly, they are more gentle on your clothes than top-loading machines that tend to agitate them vigorously to get them clean. The trade off is that a front loading machine will take longer to clean really dirty clothes.
  2. Washing machines with cold wash options will save you even more on electricity because they won’t drain your water heater. Hot water can be useful for killing bacteria, but unless your washing soiled diapers, your clothes are pretty unlikely to get you sick. Washing with cold water is more environmentally friendly, cheaper, and easier on your clothes – basically a no-brainer.
  3. Dryers can be divided into vented and ventless options. Vented dryers heat clothes and then dump the hot, damp air outside via a nearby vent. In the winter, this means that you will be heating up the air and dumping it outside while paying to heat your house with a heat pump or furnace. In the summer, the dryer will be heating up your (possibly air-conditioned) cool inside air and then dumping it outside. Either way, this is extremely inefficient. Ventless dryers, on the other hand, draw in air and then send it through a condenser to cool the air and remove the moisture. The air is then reheated and the process repeated. The moisture drawn from the air becomes liquid water, which collects in a tank or gets drained into a sink. While ventless dryers use a lot less electricity and are gentler on your clothing, they tend to take much longer to dry. Older or lower quality models have been known to run for 3 hours or so and not actually get your clothes dry. Newer models can get the job done faster but are still slower than vented dryers. 
  4. Nearly all of Europe uses ventless dryers because they are much more energy efficient and because old European houses were never designed for vented dryers. Vented dryers are outlawed in some countries, such as Switzerland, because they are energy hogs.

These houses were designed for medieval siege warfare. No, you can’t cut a hole in the wall for the vent.

  1. In the last few years, some companies have introduced heat pump dryers. These are an order of magnitude more efficient than conventional vented dryers. They pull the heat out of the surrounding air and return it to the air when they are done. They put out a bit of heat in the process, which stays in your house and is rather useful in the winter. In the summer, you can just open the windows. 

At this point I started getting really excited about buying a ventless heat pump dryer. However, as I did more research, I very disappointingly came to the conclusion that it wasn’t going to work for me. The reason is that most models of ventless heat pump dryers are compact and have a capacity in the range of 4-5 cubic feet. As a rule, a dryer should have twice the capacity volume as a washing machine, so that means that the washer in the pair will be about 2 to 2.5 cubic feet. This is about the perfect size for a family of two, or even two parents with one child. For a family of 4, most websites and sources I found highly recommend bigger machines. 

Samsung, Bosch, Blomberg and some other companies make some very well reviewed compact ventless heat pump dryers, but the only company that makes a larger model is Whirlpool, and unfortunately the machine has rather poor reviews. The complaints cite poor reliability and bad drying performance. LG used to sell a “hybrid” solution, but it had rather poor reviews and they discontinued the model. I really don’t want to shell out over $1,000 for new laundry machines only to find that I have an appliance that performs poorly or breaks down.

For a while, I strongly considered buying a smaller machine and just doing laundry more often, but with the responsibilities of two full time jobs, two demanding little kids, and an old house that needs work, my wife and I are constantly short on time. I reluctantly decided that I just didn’t want to add another burden, which meant that I decided to buy the most efficient reasonably priced vented dryer that I could find.

Picking and installing a vented dryer

The Energy Star website provides a lot of useful information on choosing an efficient dryer, including a search function that will show you dryers ranked by combined energy factor (CEF), a measure of efficiency based on the load size. Vented heat pump dryers rank the best of course, but the most efficient vented models all have a CEF of around 3.9. I settled on a 7.4 cubic foot model from LG paired with an Energy Star rated front loading washer. Consumer reports rates LG the best brand for washers and dryers because of their reliability and efficiency, so this seemed like a good choice for me.

Both the washer and dryer are eligible for rebates in Seattle. Check with your local utility and you may find that energy star appliances qualify you for rebates as well. We’ve taken advantage of rebate programs before and plan to keep doing so.

If you have a vented dryer, there are a few things you can do to make your setup more efficient. These include getting rid of an old, clogged dryer vent and installing rigid metal vent pipe instead of flexible pipe. Making sure the distance from the dryer to the vent outlet is as short as possible also helps. Replacing the flex / foil pipe with rigid pipe greatly improves the performance of the dryer. The shorter, smoother, and more direct the pipe from the dryer to the outlet, the better. Make sure to seal the joints with foil tape- not duct tape, as this will degrade or melt with the heat. Here are my before and after pictures.

My old flex line: no good! The flex line is inefficient, and this loop setup severely impairs the air flow.

After replacing the flex line with rigid pipe, the dryer vents moist air much more directly to the connected vent.

Also, when you change your dryer, you might consider also swapping out your vent. An old, clogged vent lets cold air into your house and is less efficient at letting the hot air out. At a minimum, you should clean your vent when swapping out the dryer.

The other problem that I discovered when trying to do the install myself is that the 250V wall outlet is set up for 50 amps. Modern dryers require 30 amps, and attaching the 30 amp dryer to a 50 amp outlet is a fire hazard. I hired an electrician to do to the upgrade, which is what I’d recommend for anyone without experience. Electricians are not cheap to hire, but an hour of your time will cost you a lot less than the damage from a fire!

Operating Your Washer and Dryer Efficiently

Once you’ve got modern equipment installed, you should try using it as efficiently as possible. Here are a few tips:

  • Whenever possible, cold wash your clothes. Heating up the water to wash clothing is a waste of energy (and money) in most circumstances. If you have something that’s dirty and really need to kill germs (e.g. a potty training accident), using hot water may be a very good idea. For all your other clothing, using cold water will get the job done just as well. It will also help prevent your wool and other nice clothing from shrinking.
  • Set your dryer to run in the energy preferred mode. There’s really no reason not to.
  • For the best possible results, set your dryer to finish just as the washer is finishing its load. This way, the heating element in the dryer will stay hot and require less energy to reheat.
  • Lastly, fill it up! It takes about the same amount of energy and water to run your washer and dryer regardless of the load size, so avoid doing small loads.

Results

During my first full month with the new washer and dryer, I saved 7 kWh per day, which amounts to around $28 per month in electricity.

I also saved around 15 gallons of water a day, based on the chart below. This comes out to only $24.72 in the off peak (winter months) in Seattle, including the sewer charge.

Other Options

There are a couple more things to mention. First, the cheapest and greenest option of all is to air dry your clothes on a clothes line rather than using a dryer. This does not imply being low class or tacky – in fact, most Italians don’t own a dryer and dry their clothes beneath their windowsills, and they are some of the best dressed people on the planet. I’ve seen many little cities built during the middle ages with clothing drying above the street, and they are far more beautiful than American suburbs.

There is nothing ugly or shameful about hanging your laundry out to dry – in fact, I can guarantee that your grandparents did it. However, whether or not this is an option depends on the weather.

I spent a year in England as an exchange student and did not have a dryer. In the winter, England has a rather similar climate to the Pacific Northwest, and I vividly remember that my jeans took about two days to dry on indoor clothes rack, and they smelled a little bit bad afterwards. I really would rather not dry out clothes for a family of 4 this way all winter, but I do plan on drying out some of my clothes on the line in the basement year round, and more of them in the summer.

Modern dryers automatically shut down when they sense that the clothes inside are no longer damp, so if you pull a few shirts and pairs of underwear out of the load and put them on the rack instead of into the dryer, your dryer will run for a little less time and save some energy. Also, there’s some advantage in drying your towels together and drying lighter clothing separately to make sure you don’t leave anything in the machine longer than it needs to be there.

Lastly, gas dryers are an option for some people. Burning natural gas produces a lot of carbon dioxide and there’s no way to make it green, but if you live an an area where your electricity comes from coal or gas fired power plants, it may be your best option. Keep in mind that you’ll need to pay extra for the gas connection and professional installation. 

Conclusion

Climate change often fills me with a profound sense of hopelessness mixed with fury, not least because the solutions exist and we could solve this problem with some political will but time and time again we fail to take action. We know how to generate electricity without any emissions at all. The first step should be to make our grid carbon free, and the next is to electrify as much of the transportation system as we can. To do so, it will be necessary to make our homes as energy efficient as possible. This is an area where your economic incentives already line up with your conscience – efficient appliances will save you money and cut your carbon footprint at the same time. 

1 comment on “Going for Efficiency with Washers and Dryers

  1. Pingback: Two Cheap and Easy Home Projects to Save Energy, Water, and Money

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