Gas vs electric dryers

Which is better – for saving money, for the environment?

When comparing gas vs electric dryers, you first have to ask yourself whether you’re considering the right issue. If you’re trying to cut your energy use on laundry, your clothes dryer is probably not the best place to start – instead, you should first look at your clothes washer.

The main factors to consider for a washer are how much water it uses (especially hot water) and how fast it can spin the laundry at the end of the cycle. The faster the spin cycle, the less water is left in the clothes for the dryer to handle. That means that a relatively inefficient dryer can use less energy drying a load of laundry from a high-efficiency front-loading washer, than a super-efficient dryer would use drying a load of laundry from a lower-efficiency top-loading washer.

But assuming you’ve already done what you can on the clothes washer side, and you really want to know the answer to the gas vs electric dryers debate, let’s consider some of the key issues regarding financial cost and environmental issues.

Pricing of gas vs electric dryers

When comparing gas vs electric dryers for price, there is not a lot of difference, at least in Canada, where gas dryers are more commonly used than in the US. Selection is also roughly the same in terms of quantity. Prices for gas dryers do tend to be somewhat higher, roughly $150. The price difference is mainly because there are a large number of very cheap electric dryers at the bottom end; top prices for gas vs electric dryers are about the same, around $1800.

Then there are operational costs. There are two categories of electric dryers: resistance electric dryers, and heat pump dryers. Heat pump dryers have become the norm in places outside North America, but they are quite rare here. A heat pump dryer is actually significantly more efficient than a regular electric dryer. When you compare gas vs electric dryers without considering heat pump electric dryers. gas dryers win out on the operational cost side (the cost of the energy used to dry the clothes). When you compare gas vs heat pump dryers, heat pump dryers will have a lower operational cost. (On the other hand, they are at the high end of the price range, so you need to factor the sticker price into the equation.

What about from an environmental perspective?

Almost all the heat created by burning natural gas in your gas dryer goes towards heating the clothes and evaporating the water. The same is true of the electrical heat produced in an electric dryer. The problem is that, in the case of the gas dryer, you will ALWAYS emit greenhouse gases (mainly CO2, but also some uncombusted methane, which is a much more potent greenhouse gas than CO2) while with your electric dryer, your CO2 emissions are upstream and depend on your electricity provider. If you live in a green juristdiction like Quebec where almost all the electricity comes from renewable sources, electric drying will have a much lower carbon footprint. (And don’t forget the heat pump dryer, which could mean your electric dryer has a lower carbon footprint than a gas dryer even if the electricity isn’t all green.)

On the other hand, if your local utility gets most of its electricity from coal, it may be more sensible in the short term to us a gas dryer, since only about 30-35% of the original heat in the coal gets converted into electricity (because of thermodynamic inefficiencies governed by the Carnot fuel cycle) and a further 3-7% is lost in transmission from the power plant to your house. (Also, coal has a higher CO2 output per BTU than the fossil gas that powers a gas dryer.)

Let’s look at the math:

1. Burning coal to generate electricity releases 2.117 lbs of CO2 per kwh produced. Burning fossil gas to produce electricity releases 1.314 lbs of CO2 per kwh produced. (These are average figures for US production from the Energy Information Administration, part of the DOE.) That means the CO2 emissions ratio for gas vs electric dryers is 1.314 / 2.117 or 62%, per unit of fossil fuel burned.
2. Assuming for argument’s sake that 80% of the heat from fossil gas burned in a gas dryer is used to heat the clothes (and about 25% of the fossil fuel coal heat in the case of the electric dryer, as explained above), we can multiply that 62% by (0.25 / 0.8) or 31%, which gives us about 19%.

So if you get your electricity from coal, and you already have a natural gas dryer, I’d be inclined to stick with it, at least for the short term, as you’ll cut your CO2 emissions. However, when it comes time to replace your dryer, you absolutely should go for a heat pump dryer as they can be up to 3x more efficient than gas or standard electric dryers, and we have consistently seen utilities across the globe make progressive cuts to the percentage of electricity generation coming from fossil fuels. Buying a new gas dryer now is basically locking in greenhouse gas emissions until the next time you buy a dryer, and we should avoid that at all costs.

Performance of gas vs electric dryers

There shouldn’t be any difference in the performance of gas vs electric dryers – they both dry clothes using the same technique of applying heat and airflow in a tumble dryer. The electricity used to move the tumbler is negligible. I measured my gas dryer and a fully dryer cycle took about half a kilowatt hour of electricity. (In an electric dryer almost all the electricity is used for heat, not the tumbling.)

One issue with both gas and regular electric dryers is that they draw heat from the indoor air to blow past the clothes (and in the gas dryer case, to provide oxygen to the flame so the fossil gas burns) and then pump that warm air, plus the moisture that has been extracted, to the outdoors. This in turn draws unheated air inside, which in winter means you are also paying to heat that air as it is brought in.

A heat pump dryer, on the other hand does not need to vent. Instead, it uses a closed cycle; it removes the moisture from the air it uses to dry your clothes, by passing the moist air over the condenser coils of the refrigeration cycle, so that it condenses out and goes down the same drain your washer water goes down. So not only does a heat pump dryer give you the energy savings over a regular dryer through the heat pump technology, but you don’t lose any of your precious indoor heat to venting the dryer air outside.

I have a heat pump dryer and am very happy with it. I can attest to it not wasting the indoor warmth – in fact, the small bathroom where we keep our dryer gets really warm when the dryer runs!

Best tips for saving on clothes dryers

As I mentioned at the outset, the best way to save on drying your clothes is to make sure the clothes are as dry as possible before they go into the dryer, whether you have a gas dryer or an electric one. You can do that by switching from a top-loadingto a front-loading washer; buying an extra spinner that extracts water from clothes at high speed rotation after the clothes are washed; or, best of all, hanging your clothes up on a line or laundry rack, either outside or in your basement or laundry room, and using the dryer just to finish off the drying or fluff them (as line-dried laundry sometimes can get stiff – my bathroom towels often feel like boards after I line dry them!).

And avoid gimicks like dryer balls – they just don’t work, as I explain in my dryer balls review.