Pros & Cons
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- Heats, cools, and purifies
- Numerous air quality readings
- 350-degree oscillation
- Supports voice control
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- Expensive
- Loud at high fan speeds
Dyson Hot+Cool Formaldehyde HP09 Specs
| Cost of Replacement Filters | $79.99 |
| Purification Method | HEPA |
| Removes Formaldehyde | |
| Scheduling Support | |
| Voice Control Support | Amazon Alexa |
| Voice Control Support | Google Assistant |
| Voice Control Support | Siri |
Designed for rooms of up to 800 square feet, the Dyson Hot+Cool Formaldehyde HP09 is a versatile air purifier that also provides heating and cooling with 350-degree oscillation. You can control it with your phone, voice, or the included remote, and it’s light enough to move from room to room as needed. At $849.99, it’s more expensive than most air purifiers, but its feature set, numerous air quality readings, and solid purifying performance earn it an Editors’ Choice award. If you can live without formaldehyde filtering and heating functionality, you can save some money with the Dyson Purifier Cool TP07 ($649.99), which is also an Editors' Choice winner.
Design: Unmistakably Dyson
The HP09 shares the same oval tower design as the Dyson Purifier Cool TP07. It's white with a gold cylindrical base and measures 30.0 by 9.8 by 5.1 inches (HWD). Dyson also sells a silver-tone version, the $749.99 HP07, that does not filter formaldehyde.
At 12.6 pounds, the HP09 is easy to move from room to room. The top half contains the bladeless amplifier loop fan that distributes clean air to the room, while the bottom half pulls air into the filtration system.
(Credit: John R. Delaney)On the right side are sensors that record a wide range of air quality measurements. In addition to an overall Air Quality Index (AQI) reading, the HP09 measures levels of PM2.5 (particulate matter smaller than 2.5 microns such as smoke), PM10 (particulate matter smaller than 10 microns such as pollen, dander, and dust), formaldehyde (HCHO, a colorless chemical emitted by cleaners, plywood, varnishes, and many other common household items and materials), volatile organic compounds (VOCs, such as gases from aerosol sprays and air fresheners), and nitrogen dioxide (NO2, or pollutants from smoke, gas stoves, and candles). Other onboard sensors measure the room temperature and humidity level.
The entire assembly sits on a mechanical base that provides 350 degrees of oscillation movement. In addition to a 10-speed fan that helps cool down the room, the HP09 uses Positive Temperature Coefficient (PTC) ceramic heating technology and built-in thermostats to warm the air. The front of the purifier holds a power button and a small round LED screen that displays colorful air quality statistics. Use the remote to scroll through the above-mentioned pollutant levels, as well as the aforementioned room temperature and room humidity readings.
As with the Purifier Cool TP07, the HP09 features a fully sealed filtration system that traps pollutants inside and prevents them from leaking back into the air that you breathe. It’s a three-phase filter system that uses two large semi-circular HEPA H13 filters that provide 360 degrees of filtration and remove 99.95% of pollutants such as allergens, bacteria, viruses, pollen, and mold. A pair of removable carbon filters work to remove odors and gases, while a Selective Catalytic Oxidisation (SCO) filter removes formaldehyde pollutants. The catalytic filter takes formaldehyde particles and breaks them down into carbon dioxide and water molecules.
The HEPA and carbon filters are rated to last up to 12 months before needing replacement, while the catalytic filter is permanent and does not need replacing. A new HEPA and carbon filter goes for $79.99, which is a bit more than you’ll pay for a similar filter assembly for the Airthings Renew ($69.99). That said, the Airthings filters must be replaced every six months, so the HP09 filters are more cost-effective.
(Credit: John R. Delaney)The HP09’s more expensive sibling, the $999.99 Big+Quiet Formaldehyde BP03, uses a $169.99 HEPA filter, but it is rated to last up to five years before needing replacement. The BP03 is meant for rooms up to 1,076 square feet and does not offer heating functionality.
The HP09 has dual-band Wi-Fi and Bluetooth connectivity and works with Alexa and Google Home automation platforms. It can also be controlled using Siri voice shortcuts, but it doesn’t work with Apple HomeKit or IFTTT applets. It connects to the MyDyson mobile app (available for Android and iOS), which is the same one used to control the Big+Quiet BP03 and the Purifier Cool TP07.
MyDyson App: Color-Coded for Easy Reading
Inside the MyDyson app, the HP09 screen shows both indoor and outdoor air quality data at a glance. At the top of the screen are your local outdoor temperature and humidity readings and the overall outdoor AQI (good, moderate, unhealthy for sensitive groups, unhealthy, very unhealthy, or hazardous), based on your location. Each outdoor AQI level has a distinctive color, with green being the best and dark red the worst.
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The screen consists mainly of a graphic of a house with a picture of the purifier, its name, and glanceable data from its sensors, including the current indoor air quality level, humidity level, temperature, and the most prominent type of pollutant. Indoor air quality is represented with slightly different color coding than outdoor air quality: green is good, yellow is fair, orange is poor, red is very poor, dark red is extremely poor, and purple is severe.
Tap the picture of the purifier to open a control screen where you can turn the device on and off, enable cooling, enable auto mode which adjusts the fan speed depending on the current air quality, change fan speeds (1 to 10), enable oscillation (45, 90 180, 350 degrees), set an off timer (15 minutes to 9 hours), and enable night mode, which dims the LED screen and runs at the lowest fan setting. A direction setting lets you toggle between front and back airflow.
Back on the device screen and below the picture of the purifier are buttons for power, auto mode, fan speed, and oscillation, as well as a remote control button that opens the same aforementioned control screen. Swipe up to view historical charts for general air quality, PM2.5, PM10, HCOC, VOC, NO2, temperature, and humidity readings.
(Credit: Dyson/PCMag)The HP09 comes with a small gold magnetic remote that you can magnetically attach to the top of the purifier. The remote also has power, oscillation, fan speed, auto mode, air direction, timer, and night mode buttons, an up/down heat button that turns on the warm air function and lets you set a target temperature, and an information button that changes what is shown on the onboard display. Tap this button to scroll through AQI, PM2.5, PM10, VOC, NO2, HCHO, temperature, and humidity readings.
For safety reasons, you can’t control the HP09’s heating using the mobile app. You must instead use the remote to enable heating and adjust temperature settings.
Setup and Performance: Simple and Powerful
Preparing the HP09 for first use was easy. To start, I scanned the QR code in the quick-start manual, which provided a full set of instructions. I unwrapped the HEPA and carbon filter components, removed the outside covers from the base, and pressed each filter component into place. The carbon filters go in first, followed by the HEPA filters. Once I had snapped the HEPA filters into place, I replaced the outside covers and plugged in the purifier.
Next, I downloaded the MyDyson mobile app and created an account. I tapped Add Machine on the opening screen, allowed Bluetooth, and selected the HP09. Following the instructions, I held my phone next to the purifier’s display and pressed the onboard power button to begin pairing. Once the machine was paired, I selected my Wi-Fi SSID and entered my Wi-Fi password, and the purifier was successfully added to the app. During setup, the purifier automatically connected to my Alexa account because I had previously enabled the Dyson skill. I assigned the purifier a room location and entered my date of purchase to complete the app setup.
The HP09 did an admirable job of cleansing the air in my testing. I placed it in my 110-square-foot office, where it registered a PM2.5 reading of 01. I lit a stick of incense and let it burn for 10 minutes, at which point the purifier displayed a PM2.5 reading of 225. I waited until the reading dropped to 200, set the purifier to auto mode, and the fan immediately ramped up to high speed. After three minutes, the reading had dropped to 94, and after six minutes it read 50. At the 10-minute mark, the PM2.5 level measured 22. The purifier needed a total of 19 minutes to return to the original 01 reading.
The HP09 also did a good job of heating up my office. It took 10 minutes to bring the room up to 75 degrees from a starting temperature of 65 degrees and another 8 minutes to warm it up to a balmy 80 degrees. The device is relatively quiet when running at low speed but the more the fan ramps up, the louder it gets.
Using the NIOSH Sound Level Meter iPhone app, I measured an output of 36dB with the fan running at level one, 58dB when running at level five, and 78dB at max speed (level 10). That’s significantly louder than the $749.95 Rabbit Air A3 and the Dyson Big+Quiet Formaldehyde BP03, both of which put out 50dB at their highest setting.