Wash Your Dishes Efficiently

Quick Facts Affordability Cost Savings CO2 Reduction		People often debate which uses less energy: washing dishes by hand or with a dishwasher. The right answer depends on how you wash dishes and how often, what kind of dishwasher you have and what drying methods you use. There are easy and cost-effective ways to reduce water and energy use whether you are washing by hand or with a machine. Affordability One of the most effective ways to cut down on how much energy and water you use to wash dishes is to cut down how many dishes you need to wash. Re-use your drinking glasses throughout the day and plan ahead as you cook or bake. Whether you wash them by hand or in a machine, using fewer dishes will save you work, money, water and energy. Cost savings You can save about 15% of total dishwasher energy use by selecting the air-dry cycle or opening the dishwasher door instead of using the heat drying cycle. If you choose your dishwasher's "no-heat dry" feature for an average of three loads per week, you could save $5 a year on your energy costs. Replace your 1990 dishwasher with an ENERGY STAR® machine and save up to $40 a year. Health & comfort Decreasing the energy use of washing dishes can actually save some of your personal energy too. Practices such as using fewer dishes, washing only one load per day and not pre-rinsing before loading into the dishwasher save energy and help make dishwashing less of a chore. Environmental considerations Efficient dishwashing reduces both energy and water use, which has many positive environmental implications. The soap or detergent you use will also affect the environment. Use natural, readily biodegradable soaps and use only as much as is required. Even gentle soaps can cause algal blooms and other imbalances when they drain into water bodies. Newer model dishwashers tend to require less detergent than older ones. Read the manual to ensure you aren't using more than is required.

What you need to know

Washing by hand

• Do not leave the water running to rinse dishes. If you have a sink with two basins, put soapy water in one and clear hot water in the other to rinse. If you have a single-basin sink, you can gather soapy dishes in a dish rack and rinse them with a sprayer or a pan of hot water.
• Wash glassware first, then the cleanest dishes, leaving greasy dishes and pots and pans to the end. This helps keep your water clean longer – and your dishes grease-free.
• You do not need to fill a sink with water to have enough to wash a load of dishes. Setting an appropriately sized washbasin in your sink for dishes can help keep the water you use to a minimum. Or fill the sink only a few inches full.
• Use a readily biodegradable dish soap to protect freshwater resources.
• If your household uses a lot of dishes and you need to wash them two or three times a day, you might save water and energy by using a new dishwasher to wash one full load per day. Invest in enough dishes to cover a full day of meals – so you need only to wash dishes only once a day.

Dishwashers

• Saving hot water also saves energy. 80% of the energy used by a dishwasher goes toward water heating, the rest runs the motor and the fan. Older dishwashers use 30 to 53 litres of water. Newer models (after 1994) use 15 to 38 litres. More energy-efficient models use less than 20 litres of water for a cycle.
• Wash only full loads. The dishwasher will use the same amount of water if it is half empty or completely full.
• Do not pre-rinse dishes. Most newer dishwashers do not require a pre-rinse. Scrape food and empty liquids. If you must pre-rinse, use cold water. Use energy-saving wash cycles. Most dishwashers have various wash cycles you can select. The energy-saving feature allows you to use less water on dishes that are less soiled. Cycles such as "light wash" or "light/china" save energy by using less water and running for a shorter cycle.
• Use the "No-heat" dry feature. Most dishwashers have a built-in heating element to bake dishes dry. The "No-heat" dry feature circulates room air through the dishwasher with a fan. To save even more energy, turn the dishwasher off after the final rinse and open the door to air dry.
• Do not position your dishwasher next to the refrigerator. The heat produced by the dishwasher will require your refrigerator to work harder.
• Some kinds of plastic containers may break down in the dishwasher and leach harmful chemicals. Put only dishwasher-safe items in the machine.
• Load dishes according to manufacturer's directions to allow for optimum performance.
• A dishwasher with a booster heater allows you to maintain a lower setting on your home's hot water heater. Some dishwasher models have built-in heaters to boost the water temperature to recommended levels 60°C to 63°C (140°F to 145°F). Some dishwashers preheat water automatically, while others require you to pre-select this feature. The benefit of this feature is that you are heating only the water required to wash with, instead of keeping your entire household's water heater temperature unduly high. Each 5.5°C (10°F) reduction in water heating temperature setting can result in a 3% to 5% reduction of energy consumption for water heating. Be careful, however, as keeping water below 60ºC can create bacteria and is a cause for Legionnaires disease. Buy a dishwasher with a water booster heater or "sani" setting to bring incoming water up to the recommended temperature.
• Compact dishwashers use less water and energy per wash but if you have to use it more than once a day, it is likely more efficient to use a standard size. A dishwasher that is appropriately sized for your needs will be the most efficient.

Taking it further

• Buy an energy-efficient dishwasher that is sized for your needs. EnerGuide labels will show you how much energy the machine will use. The ENERGY STAR mark on the EnerGuide label indicates the most energy-efficient models. ENERGY STAR dishwashers:
  • Are better constructed, with more-effective washing action;
  • Use smart sensors to adjust the wash cycle to match the load – reducing hot water and energy use;
  • Are at least 25% more energy-efficient than the minimum federal standard;
  • Can save up to 20% on water heating costs.
• Grey water is any used household water other than toilet water. Grey water recycling to water lawns and gardens is becoming increasingly popular. Dishwater is not the best water for recycling as it contains a high concentration of grease and soap but it can still be reused, saving litres of fresh clean water for drinking. Check first for any local grey water bylaws. See our Water Guide for more information.
• Check out the Water Guide for more information on saving water around your home.

FAQ

It takes a couple of days before we have a full load in our dishwasher. If I don't pre-rinse the dishes, the food is hardened onto them by the time we're ready to run it. Is it better to pre-rinse or to run the washer partly full?
It might be that the dishwasher you have is too big for your needs. A compact dishwasher might be a better size. Until you are ready to trade it in for a smaller one, rinse the dishes in cold water. Try to minimize the water you use by filling a basin to rinse or soak them so you don't keep the taps running.

There are two of us in our household and we wash the dishes once a day by hand. Is that more efficient than having a dishwasher for just us two?
It depends on how you wash the dishes and on what kind of a dishwasher you would buy. Most people use about 20 to 30 litres of water to hand wash a load of dishes. If you minimize your water use and rinse in a sink basin or with a sprayer, you might use only 15 to 20 litres, which is about equal to an efficient compact dishwasher.