Cado self-cleaning humidifiers raise ¥162 million ahead of Japan launch

Japanese appliance manufacturer cado has confirmed that its STEM 700iH and STEM 300H humidifiers will go on general sale on November 13, 2026, following a crowdfunding campaign that, according to the company, raised ¥162,621,416 from 3,887 supporters.

The crowdfunding campaign, which ran on Japanese platform Makuake from September 19 to November 1, has now concluded. It had already passed ¥100 million in October.

What's behind the enthusiasm? Both models promise to tackle one of the less appealing aspects of owning a humidifier: cleaning it.

Cado's Clean Heat technology targets 90 days without routine cleaning

The STEM 700iH and STEM 300H use cado's patented Clean Heat technology, combining ultrasonic humidification with automatic water heating.

Rather than continuously boiling the entire water supply, the system heats water to approximately 70°C to help suppress microbial growth. Cado claims a 99.9% reduction in tested microorganisms, including bacteria, yeast and mould, based on laboratory testing conducted under controlled conditions.

The headline feature, however, is the claimed 90-day cleaning interval.

Cado says its humidifiers can operate for an entire season without routine cleaning, although that claim comes with qualifications. Its in-house testing involved eight hours of humidification on weekdays at a low setting, alongside two daily heating cycles.

The company acknowledges that cleaning may still be necessary if dirt or slime develops during normal use. Filter cartridges also require periodic replacement.

Interestingly, the Clean Heat system can activate automatically approximately every 12 hours when water remains in the reservoir, even when humidification is switched off. In other words, the humidifier may stop producing mist without necessarily stopping its cleaning cycle.

Cado also claims energy consumption of approximately one-seventh that of a conventional steam humidifier under its specified comparison conditions. For the STEM 700iH, the company's calculations indicate approximately 500 Wh of daily consumption, compared with 3,600 Wh for a 450 W steam humidifier, assuming eight hours of use and the stated heating cycles. Actual costs will depend on usage.

STEM 700iH and STEM 300H specifications

The larger STEM 700iH is intended for living rooms and other spacious areas. It delivers up to 700 mL/h of humidification in its 30-minute rapid mode and features a 2.2-litre water tank. During normal high-output operation, that figure drops to 400 mL/h.

Measuring approximately 270 mm in diameter and 869 mm tall, it weighs around 4 kg. Its lowest stated operating noise level is 22 dBA, and an updated LCD touch panel displays humidity and operating information. The flagship also supports remote monitoring and control through connected features.

The smaller STEM 300H takes a different approach. Designed for bedrooms, children's rooms and compact spaces, it measures approximately 194 mm in diameter and 275 mm tall and weighs 2.2 kg.

Curiously, the smaller STEM 300H actually has the larger water tank, holding 2.5 litres compared with the taller model's 2.2 litres. Size isn't everything, apparently! It delivers up to 300 mL/h in its 30-minute rapid mode, dropping to 200 mL/h during normal high-output operation, while its lowest stated noise level is just 24 dBA.

Both models offer automatic, night, rapid and manual operating modes, along with LED lighting that changes colour according to humidity levels. They also include one-, four- and eight-hour automatic shut-off settings.

And what about the white powder sometimes left behind by ultrasonic humidifiers? Cado uses replaceable filter cartridges designed to capture some of the minerals responsible for these deposits. Their effectiveness and lifespan depend on the mineral content and hardness of the water.

Japan release confirmed for November 13

According to cado's latest announcement, the STEM 700iH will retail for ¥69,300, while the smaller STEM 300H costs ¥27,500, including Japanese consumption tax.

Both models are scheduled for general release in Japan on November 13 through electronics retailers, department stores, interior shops and cado's online channels. International pricing and availability have not yet been announced.

A new black finish will also be available through selected official cado stores, joining the previously announced cool grey and white versions.

For those living in colder, wetter climates, the idea of buying a machine to add moisture to the air might seem a curious one, particularly when winter already brings its fair share of damp weather. Yet indoor heating can leave rooms surprisingly dry. Perhaps the real attraction of cado's new humidifiers isn't simply adding moisture, but the prospect of doing so without adding another regular cleaning chore to the list.