Clothes washers and dryers represent one of the biggest – and most complicated – possibilities to save energy and money. Different types, different load sizes, different styles, electricity usage, water usage, spin speeds... just about every aspect of the laundry process burns energy like there's no tomorrow.

Thankfully, this also means that the laundry is a place where you can make great leaps in efficiency.

The CEE rates appliances on two scales:

• Modified Energy Factor (energy consumption)

This measures how many cubic feet of laundry can be washed and dried with 1 kWh of electricity. The scale works contrary to the other measurement – a higher rating is better in this case.

• Water Factor

Measures how many gallons of water are needed to for each cubic foot of laundry. This scale works in the other direction, with lower scores indicating better efficiency.

Buying Clothes Washers

In practical terms, this initially confusing system means that you need to look for a clothes washer with a high MEF and a low WF. As a guideline, Tier 3 appliances – the most efficient – have at least 2.40 MEF and at most 4.0 WF (March 2013).

Front-loading machines are usually more efficient (and wash better) than top-loaders. They also have faster spin speeds, which removes more water and thus cuts down your drying time and costs. Another benefit is that all front-loaders have detectors which adjust the amount of water to the weight of laundry – if you're buying a top-loader, make sure this feature is present.

Of course, whatever model you buy should have as many cycle options as possible. Your energy use can change dramatically depending on the wash and rinse temperatures.

As usual, there's a list of residential models on the CEE website .

Buying Clothes Dryers

The CEE doesn't maintain a list of efficient dryers and there's no Energy Star program to label the best because all the models used in the US have fairly similar ratings.

This means that you should keep your current dryer as long as it is in good working order and has a moisture sensor to switch itself off once your clothes are dry.

The exception to this is considering a heat pump or condensing dryer: these models funnel their exhaust back into the system, using it to pre-heat the air. Not only does this make them more efficient but it also cuts your air conditioning costs by emitting fewer hot exhaust fumes.

Usage Tips

Significant energy efficiency gains in the laundry area mostly come from how you use your appliances. Bear in mind the following tips:

Washers:

• Always use a cold rinse cycle.
• Use the lowest possible temperature washing cycle, as long as your clothes come out clean. You'll save energy every time.
• Choose an appropriate detergent for lower-temperature washes. The detergent itself won't affect energy use but it will mean you can do your laundry on a colder setting every time.

Dryers:

• Use auto-dry if you have it: a moisture sensor works better than checking by hand.
• Don't overload the dryer. Two smaller loads