Dishwasher

ENERGY STAR® dishwashers start at less than $500 and - depending on manufacturer, features and finish - can cost up to about $2,000. Replacing a 1990 dishwasher could save you about $70 a year in operating costs.	A little research and some installation work, if you do it yourself.	Replacing an old dishwasher with a new ENERGY STAR model could reduce your greenhouse gas emissions by a few hundred kilograms per year.

Approximately 80 per cent of the energy used in the dishwasher is for heating the water. New ENERGY STAR-rated models use between 30 and 75 per cent less energy depending upon the age of your old dishwasher.

Why should I consider replacing my old dishwasher?

Thanks to ever-tougher government standards and improved technologies, new dishwashers are far more energy efficient than their predecessors. A typical dishwasher built in 1984 uses more than 1,200 kilowatt hours (kwh) of energy per year and a 1990 model more than 1,000 kwh. By contrast, a standard 2004 dishwasher uses some 450kwh, while many of today's ENERGY STAR models consume less than 300 kwh. In other words, if you bought a new ENERGY STAR dishwasher, you'd be using less than one-quarter the energy of the 1984 model and less than a third that of the 1990 model. That adds up to annual energy savings of about $70-90 per year.

What are ENERGY STAR-qualified dishwashers?

Dishwashers with this label are the most energy efficient in their class. As of January 1, 2007, dishwashers must be at least 41 per cent more energy efficient than minimum federal standards to qualify for the ENERGY STAR label. Note: Natural Resources Canada (NRCan) is proposing that as of January 1, 2010, these minimum standards will be strengthened so that all new dishwashers must use no more than 335 kilowatt hours of energy per year. Currently, some dishwasher models use upwards of 470 kwh of energy per year.

A wide range of dishwasher models meet the ENERGY STAR criteria. A number now use less than 300 kwh of energy per year, and a few use less than 200 kwh. For a list of manufacturers and models of ENERGY STAR-qualified dishwashers, check this NRCan Office of Energy Efficiency dishwasher search page.

What does the number on the Energuide label indicate?

The Energuide label attached to every new dishwasher (ENERGY STAR or not) provides an estimated energy-use rating.  In this case the number refers to the amount of electricity to run the machine and to heat the water for some 215 dishwasher loads per year.  This rating is expressed in kilowatt hours per year.  However, in Alberta we mostly use natural gas to heat our water.  The EnerGuide label is still very helpful in comparing relative energy use between models in a class.

What uses more energy - the electricity to run the machine or the natural gas used (in Alberta) to heat the water?

About 80 per cent of the energy used to run a dishwasher comes from heating water.  So beyond the overall EnerGuide rating, it's worth knowing how much hot water each prospective model uses and to look for ones that consume less.  Consider that some non-ENERGY STAR models fill and drain up to five times, using more than 30 litres of hot water, per load.  Even within the ENERGY STAR category, the amount can vary considerably, with some models using up to 25 litres per load and others less than eight litres.  On average, an ENERGY STAR dishwasher will use one-third less hot water than non-qualifying models and much less than an old dishwasher.  You can find the amount of hot water each model uses from the same search page mentioned above, Office of Energy Efficiency dishwasher search page.

Do ENERGY STAR dishwashers cost a lot more than ones that don't meet that standard?

Generally speaking, any price difference is minimal and will soon be recovered in energy savings, allowing you to keep reaping these savings for the rest of your dishwashers' 13-plus-year lifespan. You should be able to find ENERGY STAR models for as little as $500. By far the biggest premium on dishwashers is for high-end brands and special features and finishes (such as stainless steel fronts) that often have little to do with energy efficiency.

Do ENERGY STAR dishwashers clean as well as non-qualifying models?

Yes. Indeed, if you are replacing an old dishwasher, you should notice that good modern dishwashers are considerably better at cleaning dishes. Because energy-efficient dishwashers are also better insulated, they're usually much quieter too.

I've heard it takes more hot water to use a dishwasher than to wash dishes by hand. Is this true?

No. Studies have shown the opposite: Most people use considerably more hot water washing a comparable number of dishes by hand - especially if they keep the water running - than by using a modern dishwasher, especially on at its most efficient settings. if you want to test this yourself, see if you can wash, and rinse, eight-to-ten full place settings (the equivalent of a full dishwasher) in the sink, using 15 measured litres of hot water - the amount consumed by many ENERGY STAR models. The other benefit of using a dishwasher is it saves you many hours at the sink.

When I'm shopping for an ENERGY STAR dishwasher, are there other energy-saving features I should look for?

Look for models with a booster heater. The heater raises the dishwasher's water temperature to about 60 degrees Celsius (140 degrees Fahrenheit), the operating temperature recommended by most manufacturers. This allows you to lower the temperature on your hot water tank to about 50-55 degrees Celsius (122-130 degrees Fahrenheit) - the maximum you should need for other uses like showers and clothes washers. For every five degrees Celsius you lower the setting on your hot water tank, expect to save three-to-five per cent on your overall hot water bill, though lowering the setting too much may increase the risk of bacteria forming in your tank.

Most new dishwashers offer other energy-saving features such as short, light or economy cycles, which clean your dishes in one detergent wash followed by two or three rinses. Some new models include sensors that measure the dirt on your dishes and automatically adjust the amount of water needed to clean them.

Another common feature is an "air dry" option instead of the electric dry cycle. Use it. Air drying is just as effective and uses no energy, though it might take a little longer. At the same time, steer clear of using energy-sapping options such as "plate warmers" - it's better to use the residual oven heat from cooking your dinner.

Once I've bought an ENERGY STAR dishwasher, what can I do to maximize its energy efficiency?

• Run your dishwasher only when it's full. If it takes you a while to fill your dishwasher, some new "drawer" models allow you to wash just half the dishwasher space.
• Experiment with different settings and choose one that offers the best wash with the fewest, shortest cycles.
• Scrape excess food off your dishes, but don't bother rinsing them before putting them in the dishwasher. Modern dishwashers and detergents should properly clean most dirty dishes.
• Use the "air dry" option instead of the electric drying cycle.

What about using an environmentally-friendly dishwasher detergent?

Check with your local supermarket or eco-store to see if it offers natural detergents, which typically are rapidly biodegradable and free of phosphates, chorine, dyes and fragrances.

Can I recycle my old dishwasher?

When you buy an ENERGY STAR dishwasher, ask retailers if they will remove and recycle your old dishwasher. If not, check with local scrap metal dealers to see if they will pay for, or accept, your dishwasher.