Need to know
- Heat pump dryers are expensive to buy but cheap to run, so they’re a good choice for heavy users
- The traditional vented dryer can last a long time due to its simplicity, but it's a very energy-intensive appliance
Want to keep your energy bills lower this winter but don't know where to start? Maybe you should look to the laundry, particularly if you use a clothes dryer regularly.
The traditional vented dryer is a simple but very energy-intensive appliance, so when it comes time to replace your old one you might want to consider a heat pump model.
On this page:
- What is a heat pump dryer?
- How does a heat pump dryer work?
- How much energy does a heat pump dryer use?
- How long does a heat pump dryer take to dry?
- Do heat pump dryers have reverse tumbling?
- Where does the moisture go in a heat pump dryer?
- Which dryer is right for you?
What is a heat pump dryer?
Heat pump dryers use heat exchanger technology and they're significantly more energy-efficient than vented or condenser dryers – we're now seeing nine and even 10-star energy ratings from several manufacturers (as opposed to two stars, which is typical for a vented dryer).
While all clothes dryers work by blowing hot air through your wet laundry, heat pump dryers are very different appliances compared with vented (or even condenser) dryers, and if you're considering one there are a few things to weigh up.
How does a heat pump dryer work?
When it boils down to it, your old vented dryer is just a sheet metal box with four parts – a heater, motor, timer and fan. That simplicity is why your circa-1982 Hoover is more than likely still doing faithful duty in your laundry – there's just not much in it that can break.
Heat pump dryers, on the other hand, incorporate a cornucopia of components and several sophisticated technologies to give them that energy efficiency, as well as a hefty price tag.
Heat pump dryers use around a third of the energy of a conventional vented dryer
One such component you'll find in a heat pump dryer (and your fridge and air conditioner) is refrigerant. Refrigerant's pretty amazing stuff – it needs to boil, and then condense at very specific temperatures and pressures, and it's integral to the function of a heat pump.
The refrigerant used in most heat pump clothes dryers, Tetrafluoroethane or R134A, is non-flammable and non-ozone depleting, but care still needs to be taken when working with it or repairing or recycling a heat pump dryer, making end-of-life disposal more challenging. Some manufacturers are also starting to use other refrigerants, including carbon dioxide and even methane. The only gas used in a vented dryer is air.
How much energy does a heat pump dryer use?
The biggest argument in favour of heat pump dryers is energy efficiency. They use around a third of the energy of a conventional vented dryer, which has a big impact on your energy bill.
They use around a third of the energy of a conventional vented dryer
We've found heat pump dryers have an average 10-year running cost of $680, compared with an average of $1985 for vented dryers. And that's based on one run per week – if you're a heavy dryer user then the savings will be bigger, and you'll rapidly justify the higher purchase price.
Of course, the flipside is also true – heat pump dryers are expensive to buy and if you rarely use your dryer then you won't recoup the initial outlay through energy savings, so consider your usage patterns and the total cost of ownership (purchase price plus running costs) before deciding which dryer technology to pursue.
How long does a heat pump dryer take to dry?
Heat pump dryers can't get the air as hot as a vented dryer can. But lower temperatures tend to be kinder to your clothes, so combined with sensor drying technology it means your socks won't come out crispy and singed from over-drying.
That being said, it'll take longer to dry your laundry – 233 minutes on average for a full load, compared with 177 minutes for vented dryers in our test. That's still not as long as the drying cycle on a washer dryer combo, which can take as long as 6.5 hours, but it's a big consideration if you're drying multiple loads of clothes per day.
As heat pump dryers are more complex than vented dryers, they're likely to offer you a wider range of programs, such as woollens, sportswear or iron dry. Iron dry means clothes may still feel a little damp, but they'll be easier to iron. If you're putting them away for the winter though, you might want to use an extra-dry program.
Do heat pump dryers have reverse tumbling?
Heat pump dryers typically use the same motor to drive the drum and fan, which makes it difficult to allow for reverse tumbling, as reversing the rotation of the drum would also reverse the fan, pushing hot air backwards through the dryer, potentially damaging it, and blowing cold air onto your clothes.
Without reverse tumbling, large items like sheets and towels can wad up into a tight ball or laundry sausage, without drying properly. Manufacturers try to get around this problem by reversing the drum for short periods – say, 30 or 90 seconds – in an attempt to untangle their contents, but this may not be sufficient, and you may need to turn the laundry sausage around manually mid-cycle to get it to unwind.
Where does the moisture go in a heat pump dryer?
For wet clothes to become dry, the moisture has to go somewhere. The way your dryer handles this has a big impact on home comfort – vented dryers, as the name suggests, vent hot, wet air straight into the laundry. If you don't have great ventilation this can rapidly make it feel like a sauna, and the problem's compounded because we use our dryers more on rainy (humid) days.
The moisture is collected in an onboard water tank instead of vented into the room
Heat pump dryers, on the other hand, are condenser dryers. This means the moisture is collected in an onboard water tank instead of vented into the room. You do have to occasionally empty the tank but you can use this water on your garden, or you can plumb the dryer into a drain.
If you have a poorly ventilated laundry but can't justify springing for a heat pump dryer (or a condenser dryer for that matter) then look for a vented dryer, with an option for ducting. A ducting kit allows you to direct the hot, wet exhaust from your vented dryer straight outside.
Which dryer is right for you?
It depends on how much you use your dryer. If you're running it daily then in dollar terms a heat pump dryer will be the way to go. If you only use your dryer occasionally, a cheap vented model makes more financial sense. As for which is better for the environment?
A well-used heat pump dryer is more energy-efficient, but there are fewer materials in a vented dryer, and a good deal more of them are readily recyclable at the end of the machine's life. If at all possible though, we recommend using the free solar clothes dryer in your backyard.
Stock images: Getty, unless otherwise stated.
