Gas vs. Electric: Which dryer is more energy efficient?

According to the Consumer Energy Center, the clothes dryer (whichever type you have) is the second most energy-hungry appliance in the house — only the refrigerator uses more power. Dryers are measured by a standard called the energy factor, which measures pounds of clothes per kilowatt hour of electricity. (This standard is also used in a similar application when measuring the power usage of water heaters.) The energy factor's ultimate cost depends on current electricity rates, but the Consumer Energy Center says the average household will spend about $85 per year to keep its dryer juiced.

Shopping for a clothes dryer might be a little off-putting — many models are available in both gas and electric versions, and unlike nearly every other type of appliance at your chosen electronics or home store, clothes dryers don't display those ubiquitous Energy Star rating placards. Energy Star is a voluntary label that spotlights the most efficient appliances in each class, but since all dryers have similar energy requirements, they don't qualify for the program. For that same reason, clothes dryers are also exempt from displaying the EnergyGuide placard (which is usually a requirement).

When you're researching your new clothes dryer, you can expect most gas models to have an energy factor of about 2.67 and above. This is a rather high energy factor, but it's a little less than electric models. That difference ends up being about 50 percent less power per load (and therefore save you more on your electricity bill) [source: Consumer Energy Center]. So, gas dryers usually cost more up front, but they save money in the long run.

A slightly higher up-front price tag in exchange for money and energy savings for years to come? It sounds easy, but unfortunately, your decision might not be that simple. If your laundry area isn't equipped for a gas dryer, the upgrade will be a pricey investment (if it's even possible at all). First, gas dryers require a gas line connection; if you don't already have one, you're probably out of luck, since they're dangerous and expensive to install in an occupied residence. If you've got one, though, that gas line will provide a potent source of heat.

A gas clothes dryer also requires a vent to expel the moisture removed from your clothes. It removes condensation in the form of hot steam, which must be quickly and safely moved outside the residential area. In most places, building codes require this vent to end up outdoors to prevent any danger from gas leaks. Unfortunately, condo and apartment dwellers might not be able to install gas dryers unless a suitable venting solution — outdoors or to a common HVAC system — has already been incorporated.

If your place doesn't have the right hookups, though, a gas dryer might not be for you. On the next page, we'll discuss alternative drying options.

No gas hookup? No problem! The energy factor of electric clothes dryers starts at 3.01, slightly higher than their gas counterparts, but the difference is such that each load of laundry will cost about twice as much as a gas dryer would cost. Electric dryer models cost a little less up front, though, and they're often easier and less expensive to install.

If you choose an electric dryer, you're spared the inconvenience of venting, which makes electric dryers a convenient choice in multi-family and small homes. (All compact and combination units, especially popular with apartment-dwellers, are electric.) All you need is a standard electrical outlet!

Most electric dryers remove moisture through condensation; that is, once the hot air collects moisture, it's cooled, and the resulting water vapor ends up in a tank or tray that must be emptied periodically. However, this extra power use requires an upgrade in infrastructure. Electric dryers use a 240-volt outlet, twice the standard household current, so if you don't have one, you'll need to hire an electrician to hook you up.

If both electric and gas dryers are beginning to sound complicated, there's always a greener solution. In fact, the simplest solution might not be an option for space-constrained urban dwellers, but if you've got some yard space to your name, put nature to work. If you want to really reduce your operating costs, you have a choice beyond either natural gas or electric heat. You can hang your clothes outside!

Despite some drawbacks (like dependency on the season and weather, or the restrictions of finicky homeowners' associations) using a clothesline is the least expensive, most energy-efficient way to dry clothes. The sun and wind are extremely effective — no 240-volt outlet or steam vents necessary. Your clothes will also stay in better condition.

Keep reading for more household tips and energy conservation pearls of wisdom.