- Better: maximum noise The HP09 was louder at maximum speed than the Dyson Big+Quiet Formaldehyde BP03.
Dyson Purifier Hot+Cool Formaldehyde, HP09 Review
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 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 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.
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
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One expert praised Dyson warranty support and prepaid repair or replacement handling.
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One long-term reviewer said the Dyson cleared heavy dust and debris quickly after a ceiling collapse.
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Video testing showed PM2.5 readings rising during smoke tests and being treated as meaningful by the reviewer.
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Wi-Fi reliability was positive in the one detailed test, with no network connection problems reported.
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Design was one of the strongest positives, with frequent praise for the sleek, stylish, premium look.
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Build quality was widely praised as premium and well-made, including filter seals and overall Dyson construction.
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Smoke removal was one of the strongest demonstrated uses across incense, candles, burned food, and PM2.5 tests.
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Reviewers with allergies or hay fever often reported less sneezing, better symptoms, or better sleep with the purifier running.
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A customer with dogs praised the unit as the best filtration they had used, supporting pet-related air cleaning.
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Airflow direction and tilt were praised for sending filtered air backward or aiming the unit more precisely.
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Experts liked the LCD and color screen for showing air quality and pollutant data clearly.
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Real-time monitoring was a major strength, with detailed app graphs, pollutant data, and visible sensor reactions.
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Experts and overview content praised the multi-stage sealed filtration system.
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Hay fever and pollen evidence was positive, with one reviewer reporting reduced suffering on high-pollen days.
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Formaldehyde removal was usually treated as a meaningful differentiator, with praise for detection and catalytic destruction.
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True HEPA evidence was favorable, with experts emphasizing fully sealed HEPA H13 filtration.
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Reviewers liked the 10-speed range and adjustable output across modes.
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Sleep and night use were generally praised for quiet operation, white noise, dimming, and timers.
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Overall sentiment ranged from enthusiastic recommendations to a few strong customer rejections, producing a mixed but generally positive pattern.
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Ease of use was mostly strong, although some reviewers found initial filter setup or purification-only airflow direction fiddly.
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The app was repeatedly described as easy, useful, and reliable, though one customer reported offline connection failures.
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Voice assistant support was viewed as convenient, with Alexa, Google Assistant, and Siri mentioned positively.
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Filter life was generally viewed positively, with several reviewers reporting about a year or limited replacements over long use.
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VOC reduction was supported by carbon filtration and aerosol/cooking tests showing the unit registering and clearing gases.
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Reviewers described the carbon filter as useful for odors and gases, with one video reviewer praising the activated-carbon filter quality.
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Setup documentation was praised for providing clear instructions through the quick-start QR code.
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Heating performance was frequently praised as fast, warm, and useful, though some users disliked energy use or heat-control limits.
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Filter access and cleaning were mostly easy, with one review noting more frequent outer-shroud cleaning.
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Energy evidence was mixed-positive overall, with expert praise for efficient use but one video warning about heater power draw.
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Room coverage evidence was positive for rated coverage and heating a whole room quickly.
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Auto mode was generally useful for reacting to changing air quality, with one caveat that response depends on being in Auto mode.
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HEPA filtration was praised for sealed H13 performance, though one customer did not recommend it as a heater plus HEPA purchase.
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Safety-related evidence was mixed: reviewers praised safe design, while UL-related restrictions frustrated app-heating users.
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One expert calculated enough airflow to clean a standard bedroom multiple times per hour at maximum speed.
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Portability was generally positive because the unit is movable, though not always compact or effortless.
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VOC and gas sensor evidence was positive but not flawless, with tests showing detection after short delays.
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Purification evidence was mostly positive, especially for smoke, dust, odors, and quick room cleanup, but several reviews reported weak or failed purification.
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Noise evidence was split: many found it quiet at lower settings or sleep use, while others found high speeds loud.
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Odor reduction was often positive for cooking, smoke, fragrances, and general smells, with one severe odor case reporting failure.
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Many reviewers saw the sensors react to smoke, cooking, odors, or formaldehyde, while some customer reviews said readings missed obvious pollution.
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Scheduling was praised as easy by one customer but criticized when heat scheduling was unavailable.
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Remote control feedback was mixed, from easy magnetic storage to complaints about button sensitivity and required heat controls.
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Most reviewers liked the circulation and oscillation, though a few found fan output weak compared with cheaper fans or older models.
Cons
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Filter cost drew mixed reactions: some saw it as acceptable or cost-effective, while others called replacements expensive.
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Size feedback was mixed: experts liked the compact footprint, while customers and video reviewers sometimes found it large or smaller than expected.
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CADR-related evidence was mixed: one review found acceptable calculated clean-air rates, while another criticized weak CADR for the price.
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Value was the most mixed theme: reviewers liked the all-in-one versatility but repeatedly flagged the high price.
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Particle-removal tests were mixed, from weak ambient reductions to strong smoke, match, and dust removal.
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Smart features were useful overall but scored down by customers who could not control heating through the app.
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Power evidence was negative in customer/video comments about power use, especially when used for heating.
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Reliability evidence was negative in customer reports of units stopping after weeks or months.
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One customer reported poor arrival condition with parts and packaging scattered in the box.
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Durability evidence was negative from a customer whose unit broke in under a year.
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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
- Review score
- 4.9
- Review score
- 4.3
- Review score
- 4.2
Article Reviews
- Review score
- 4.7
- Review score
- 4.0
- Review score
- 3.7
- Review score
- 4.6
Consider This Instead
If you want better durability
Choose Coway Airmega 200M. It scores 5.0 vs 1.0 for durability, with a 4.1 overall score.
If you want better reliability
Choose Coway Airmega 250. It scores 4.8 vs 1.0 for reliability, with a 4.3 overall score.
If you want better mold spore reduction
Choose Winix 5300-2. It scores 4.8 vs 1.0 for mold spore reduction, with a 4.1 overall score.
If you want better power consumption
Choose Coway Airmega Mighty2 AP-1512N. It scores 5.0 vs 1.5 for power consumption, with a 4.0 overall score.
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