Dyson Purifier Hot+Cool Formaldehyde, HP09

Dyson Purifier Hot+Cool Formaldehyde, HP09 Review

Brand: Dyson
Released: April 1, 2021
Updated: 2 hours ago
3.7
Overall review score Expert score: 4.3 Customer score: 3.0
284
Review evidence points
54
Scored features
43
Total reviews
17 expert / 26 customer

Bottom Line

Choose the Dyson HP09 for premium design, heating, smart air data, and broad purification. Skip it if you need budget value, true air conditioning, or maximum clean-air output per dollar.

Best for

Best for buyers who want one premium device for heating, fan airflow, purification, formaldehyde monitoring, detailed app data, and allergy or odor management. It fits people who value design and year-round versatility as much as raw purifier output.

Not for

Not for shoppers who mainly need a low-cost purifier, true room air conditioning, or the highest CADR per dollar. It is also a poor fit if heat control through the app is essential.

Verdict

The Dyson Purifier Hot+Cool Formaldehyde HP09 earns its strongest praise as a polished all-in-one appliance: reviewers repeatedly liked its design, heating, app data, smoke and odor response, formaldehyde focus, and allergy-related comfort. It is less convincing as a pure value play. Several tests and customers found cooling expectations misleading, high-speed noise noticeable, replacement filters pricey, and clean-air output weaker than less expensive dedicated purifiers. The evidence supports it best for people who will use the heater, fan, purifier, sensors, app, and formaldehyde feature together, not shoppers seeking the cheapest or fastest standalone purifier.

Compared in Reviews

Products reviewers directly compared with this model, grouped into quick takeaways.

  • Alternative: price and missing heat/formaldehyde features PCMag says the TP07 is cheaper if heating and formaldehyde filtering are unnecessary.

AEG AX91-604GY Connected Air Purifier

  • Better: cooking-fume clearing speed Ideal Home says the AEG cleared cooking fumes faster than the Dyson in its test.

Feature Scorecards

Summary

54 reviewed features
  • Very positive 4.5-5.0 37% 20 features
  • Positive 3.5-4.4 43% 23 features
  • Neutral 2.5-3.4 9% 5 features
  • Negative 1.5-2.4 4% 2 features
  • Very negative below 1.5 7% 4 features

Pros

  • 5.0
    based on 1 review
    customer support: 5.0, based on 1 review
    One expert praised Dyson warranty support and prepaid repair or replacement handling.
  • 5.0
    based on 1 review
    dust removal: 5.0, based on 1 review
    One long-term reviewer said the Dyson cleared heavy dust and debris quickly after a ceiling collapse.
  • 5.0
    based on 1 review
    PM2.5 detection: 5.0, based on 1 review
    Video testing showed PM2.5 readings rising during smoke tests and being treated as meaningful by the reviewer.
  • 5.0
    based on 1 review
    Wi-Fi reliability: 5.0, based on 1 review
    Wi-Fi reliability was positive in the one detailed test, with no network connection problems reported.
  • 5.0
    based on 13 reviews
    design and appearance: 5.0, based on 13 reviews
    Design was one of the strongest positives, with frequent praise for the sleek, stylish, premium look.
  • 4.9
    based on 5 reviews
    build quality: 4.9, based on 5 reviews
    Build quality was widely praised as premium and well-made, including filter seals and overall Dyson construction.
  • 4.8
    based on 5 reviews
    smoke removal: 4.8, based on 5 reviews
    Smoke removal was one of the strongest demonstrated uses across incense, candles, burned food, and PM2.5 tests.
  • 4.8
    based on 6 reviews
    allergen reduction: 4.8, based on 6 reviews
    Reviewers with allergies or hay fever often reported less sneezing, better symptoms, or better sleep with the purifier running.
  • 4.8
    based on 1 review
    pet dander removal: 4.8, based on 1 review
    A customer with dogs praised the unit as the best filtration they had used, supporting pet-related air cleaning.
  • 4.8
    based on 2 reviews
    adjustable vents: 4.8, based on 2 reviews
    Airflow direction and tilt were praised for sending filtered air backward or aiming the unit more precisely.
  • 4.7
    based on 2 reviews
    display readability: 4.7, based on 2 reviews
    Experts liked the LCD and color screen for showing air quality and pollutant data clearly.
  • 4.7
    based on 9 reviews
    real-time air quality monitoring: 4.7, based on 9 reviews
    Real-time monitoring was a major strength, with detailed app graphs, pollutant data, and visible sensor reactions.
  • 4.6
    based on 2 reviews
    filter stages: 4.6, based on 2 reviews
    Experts and overview content praised the multi-stage sealed filtration system.
  • 4.6
    based on 1 review
    pollen removal: 4.6, based on 1 review
    Hay fever and pollen evidence was positive, with one reviewer reporting reduced suffering on high-pollen days.
  • 4.6
    based on 6 reviews
    formaldehyde removal: 4.6, based on 6 reviews
    Formaldehyde removal was usually treated as a meaningful differentiator, with praise for detection and catalytic destruction.
  • 4.6
    based on 2 reviews
    true HEPA filter: 4.6, based on 2 reviews
    True HEPA evidence was favorable, with experts emphasizing fully sealed HEPA H13 filtration.
  • 4.5
    based on 2 reviews
    fan speed options: 4.5, based on 2 reviews
    Reviewers liked the 10-speed range and adjustable output across modes.
  • 4.5
    based on 4 reviews
    sleep mode: 4.5, based on 4 reviews
    Sleep and night use were generally praised for quiet operation, white noise, dimming, and timers.
  • 4.5
    based on 15 reviews
    overall satisfaction: 4.5, based on 15 reviews
    Overall sentiment ranged from enthusiastic recommendations to a few strong customer rejections, producing a mixed but generally positive pattern.
  • 4.5
    based on 8 reviews
    ease of use: 4.5, based on 8 reviews
    Ease of use was mostly strong, although some reviewers found initial filter setup or purification-only airflow direction fiddly.
  • 4.4
    based on 11 reviews
    app connectivity: 4.4, based on 11 reviews
    The app was repeatedly described as easy, useful, and reliable, though one customer reported offline connection failures.
  • 4.4
    based on 4 reviews
    voice assistant compatibility: 4.4, based on 4 reviews
    Voice assistant support was viewed as convenient, with Alexa, Google Assistant, and Siri mentioned positively.
  • 4.4
    based on 4 reviews
    filter life: 4.4, based on 4 reviews
    Filter life was generally viewed positively, with several reviewers reporting about a year or limited replacements over long use.
  • 4.4
    based on 2 reviews
    VOC reduction: 4.4, based on 2 reviews
    VOC reduction was supported by carbon filtration and aerosol/cooking tests showing the unit registering and clearing gases.
  • 4.3
    based on 3 reviews
    activated carbon filter: 4.3, based on 3 reviews
    Reviewers described the carbon filter as useful for odors and gases, with one video reviewer praising the activated-carbon filter quality.
  • 4.3
    based on 1 review
    documentation quality: 4.3, based on 1 review
    Setup documentation was praised for providing clear instructions through the quick-start QR code.
  • 4.3
    based on 23 reviews
    heating performance: 4.3, based on 23 reviews
    Heating performance was frequently praised as fast, warm, and useful, though some users disliked energy use or heat-control limits.
  • 4.3
    based on 4 reviews
    maintenance ease: 4.3, based on 4 reviews
    Filter access and cleaning were mostly easy, with one review noting more frequent outer-shroud cleaning.
  • 4.3
    based on 2 reviews
    energy efficiency: 4.3, based on 2 reviews
    Energy evidence was mixed-positive overall, with expert praise for efficient use but one video warning about heater power draw.
  • 4.3
    based on 2 reviews
    room coverage: 4.3, based on 2 reviews
    Room coverage evidence was positive for rated coverage and heating a whole room quickly.
  • 4.2
    based on 5 reviews
    auto mode performance: 4.2, based on 5 reviews
    Auto mode was generally useful for reacting to changing air quality, with one caveat that response depends on being in Auto mode.
  • 4.2
    based on 4 reviews
    HEPA filtration: 4.2, based on 4 reviews
    HEPA filtration was praised for sealed H13 performance, though one customer did not recommend it as a heater plus HEPA purchase.
  • 4.2
    based on 4 reviews
    safety certifications: 4.2, based on 4 reviews
    Safety-related evidence was mixed: reviewers praised safe design, while UL-related restrictions frustrated app-heating users.
  • 4.2
    based on 1 review
    air changes per hour: 4.2, based on 1 review
    One expert calculated enough airflow to clean a standard bedroom multiple times per hour at maximum speed.
  • 4.2
    based on 4 reviews
    portability: 4.2, based on 4 reviews
    Portability was generally positive because the unit is movable, though not always compact or effortless.
  • 4.1
    based on 2 reviews
    VOC sensor accuracy: 4.1, based on 2 reviews
    VOC and gas sensor evidence was positive but not flawless, with tests showing detection after short delays.
  • 4.1
    based on 16 reviews
    air purification performance: 4.1, based on 16 reviews
    Purification evidence was mostly positive, especially for smoke, dust, odors, and quick room cleanup, but several reviews reported weak or failed purification.
  • 4.0
    based on 18 reviews
    noise level: 4.0, based on 18 reviews
    Noise evidence was split: many found it quiet at lower settings or sleep use, while others found high speeds loud.
  • 3.8
    based on 5 reviews
    odor reduction: 3.8, based on 5 reviews
    Odor reduction was often positive for cooking, smoke, fragrances, and general smells, with one severe odor case reporting failure.
  • 3.7
    based on 8 reviews
    air quality sensor accuracy: 3.7, based on 8 reviews
    Many reviewers saw the sensors react to smoke, cooking, odors, or formaldehyde, while some customer reviews said readings missed obvious pollution.
  • 3.6
    based on 3 reviews
    scheduling options: 3.6, based on 3 reviews
    Scheduling was praised as easy by one customer but criticized when heat scheduling was unavailable.
  • 3.6
    based on 7 reviews
    remote control: 3.6, based on 7 reviews
    Remote control feedback was mixed, from easy magnetic storage to complaints about button sensitivity and required heat controls.
  • 3.5
    based on 21 reviews
    air circulation: 3.5, based on 21 reviews
    Most reviewers liked the circulation and oscillation, though a few found fan output weak compared with cheaper fans or older models.

Cons

  • 3.3
    based on 4 reviews
    filter replacement cost: 3.3, based on 4 reviews
    Filter cost drew mixed reactions: some saw it as acceptable or cost-effective, while others called replacements expensive.
  • 3.1
    based on 4 reviews
    size and footprint: 3.1, based on 4 reviews
    Size feedback was mixed: experts liked the compact footprint, while customers and video reviewers sometimes found it large or smaller than expected.
  • 3.1
    based on 2 reviews
    CADR rating: 3.1, based on 2 reviews
    CADR-related evidence was mixed: one review found acceptable calculated clean-air rates, while another criticized weak CADR for the price.
  • 3.0
    based on 21 reviews
    value for money: 3.0, based on 21 reviews
    Value was the most mixed theme: reviewers liked the all-in-one versatility but repeatedly flagged the high price.
  • 2.9
    based on 2 reviews
    particle removal effectiveness: 2.9, based on 2 reviews
    Particle-removal tests were mixed, from weak ambient reductions to strong smoke, match, and dust removal.
  • 1.8
    based on 2 reviews
    smart features: 1.8, based on 2 reviews
    Smart features were useful overall but scored down by customers who could not control heating through the app.
  • 1.5
    based on 2 reviews
    power consumption: 1.5, based on 2 reviews
    Power evidence was negative in customer/video comments about power use, especially when used for heating.
  • 1.0
    based on 3 reviews
    reliability: 1.0, based on 3 reviews
    Reliability evidence was negative in customer reports of units stopping after weeks or months.
  • 1.0
    based on 1 review
    condition on arrival: 1.0, based on 1 review
    One customer reported poor arrival condition with parts and packaging scattered in the box.
  • 1.0
    based on 1 review
    durability: 1.0, based on 1 review
    Durability evidence was negative from a customer whose unit broke in under a year.
  • 1.0
    based on 1 review
    mold spore reduction: 1.0, based on 1 review
    One customer used it around mold-related basement air and felt the product failed to respond or improve conditions.

Compared With Category Average

Compared with other Air Purifiers, this product is above average in customer support, documentation quality, below average in mold spore reduction, reliability, power consumption.

Summary

8 compared features
  • Above average 0.4+ pts higher 25% 2 features
  • Same as average within 0.3 pts 0% 0 features
  • Below average 0.4+ pts lower 75% 6 features
Attribute This product Category average Difference
mold spore reduction 1.0 3.9 -2.9
reliability 1.0 3.5 -2.5
power consumption 1.5 4.0 -2.5
durability 1.0 3.5 -2.5
customer support 5.0 2.7 +2.3
smart features 1.8 3.5 -1.8
particle removal effectiveness 2.9 4.4 -1.5
documentation quality 4.3 2.8 +1.5

FAQ

Does the Dyson HP09 purify air well?

Most evidence says yes for smoke, odors, dust events, allergens, and general air-quality cleanup, but some tests found slower or weaker particle reduction than cheaper dedicated purifiers.

Does it actually cool a room?

It works as a fan and can feel cooling when airflow reaches you, but several reviewers stressed it is not an air conditioner and will not truly lower room temperature like one.

Is the heating function good?

Heating is one of the better-supported strengths. Many reviewers said it warmed rooms quickly, though one video reviewer disliked the power draw when using it as a heater.

Is the app useful?

Yes. Reviewers repeatedly praised the MyDyson app for setup, controls, air-quality graphs, pollutant details, and remote monitoring, though heat controls are restricted by safety rules.

Is it quiet enough for bedrooms?

Usually at low or night settings. Many reviewers found it quiet or sleep-friendly, but high fan speeds were often described as loud or noticeably noisy.

Are replacement filters expensive?

They are a recurring cost concern. Some reviewers considered the annual cost reasonable, while others called replacement filters expensive compared with mid-priced purifiers.

Who should pay extra for the formaldehyde model?

The strongest case is for homes with new furniture, renovations, smoke, gas cooking, or concern about formaldehyde and VOCs. If you do not need that feature, some reviews suggest cheaper Dyson or non-Dyson alternatives.

Sample Expert Reviews We Analyzed

These are a few of the reviews included in our analysis.

Video Reviews

Article Reviews

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