The best dehumidifiers for drying clothes indoors

Drying clothes indoors does not remove water from your house. It moves it from the washing to the air, and then from the air to the coldest surfaces in the building. A dehumidifier is the step that actually takes it out.

1. Certified IEF. Integrated energy factor, liters of water removed per kilowatt-hour, from the federal test. For this job it is not an abstraction — it is the price of drying, divided directly into the electricity rate.
2. Capacity on DOE Appendix X1. The comparable measurement. Several makers also print a bigger pint figure taken at a warmer, wetter condition, and we use the federal one.
3. Whether it works at the room’s temperature. Laundry rooms are frequently the coldest room in the house, and a compressor dehumidifier frosts rather than drains below roughly 60 F. This outranks efficiency, because the wrong technology fails completely rather than expensively.
4. Drainage. A continuous hose matters more here than almost anywhere else: laundry drying is a multi-liter job and a bucket you have to empty mid-cycle stops the machine.
5. What is published at all. No dehumidifier publishes a noise rating — the certified dataset has no acoustic field for any of its 559 models. We show that as absent rather than filling it in.

We have tested none of these. Every figure is from the federal certified dataset or the manufacturer’s own page, with our arithmetic marked as ours. How we pick.

This is the one appliance category where the efficiency rating converts into the task without any assumptions. IEF is liters per kilowatt-hour; electricity has a price per kilowatt-hour; so the cost of removing a liter is the rate divided by the IEF.

Two things fall out of that table. The spread across the whole certified field is only about three cents a liter, so efficiency is not where this decision is won. And the capacity column spans two and a half times, which is where it is won: a machine that cannot keep ahead of a loaded airer runs all night at any efficiency.

One honest caveat on every capacity figure here. The federal test is run warm and humid. A cool laundry room will produce well under the rated figure, which is a second reason to buy more capacity than the arithmetic suggests.

We cannot give you a like-for-like comparison, and it is worth saying why rather than inventing one. ENERGY STAR publishes savings for certified dryers, not an energy figure per load: “A full-size, electric clothes dryer that has earned the ENERGY STAR saves approximately $210 in energy bills over the life of the product”, and heat-pump models “use around 70% less energy than a conventional clothes dryers”. There is no published kWh-per-cycle on that page to divide by, so there is no honest per-load number to put against 8.8¢ a liter.

What we can say with confidence is the structural difference. A dryer heats water out of fabric and vents it outside. An airer plus a dehumidifier evaporates the water at room temperature and condenses it into a tank. Room-temperature evaporation needs no heating energy, which is the whole reason the second route is cheap — but it is also slow, and it puts every gram of that water through the air of your house on the way.

If you do use a dryer, the EPA has one instruction about it: “Vent appliances that produce moisture, such as clothes dryers, stoves, and kerosene heaters to the outside where possible.” An unvented or badly ducted dryer is the largest single moisture source in most houses, and it is the same water an airer would have released, delivered faster.

• Start with the room temperature, not the capacity. Below about 60 F, a compressor unit is off the table however good its IEF is.
• Then buy more capacity than the square footage suggests. A loaded airer is a far heavier moisture load than ordinary room damp, and the rated pint figure is measured in warmer, wetter air than your laundry room has.
• Insist on continuous drainage if you will do this weekly. Several liters per session means a tank you would otherwise empty mid-job. Hose and pump options.
• Then, and only then, compare IEF. It is worth about three cents a liter across the entire certified field.