The Dyson Purifier Hot+Cool Purifying Heating Fan HP4B is a Costco-exclusive variant of the Dyson Purifier Hot+Cool Purifying Heating Fan HP04. It's an all-in-one device that functions as an oscillating cooling fan, space heater, and air purifier. It features Wi-Fi connectivity, so you can remotely operate it with your smartphone via the MyDyson app or with voice commands made using Amazon Alexa, Apple Siri, or Google Home.
Our Verdict
The Dyson HP4B is an inadequate option for pet owners. It struggles with trapping really fine particles like cat dander, and its clean air delivery rate is pretty slow. On the upside, you can operate it from far away, and it makes very little noise while running at its lowest fan speed unless you turn the heater on.
- Also functions as a cooling fan or space heater.
- Automatic fan speed adjustment.
- Poor particle filtration performance.
- Low clean air delivery rate.
- Noisy operation when heater is turned on.
The Dyson HP4B is a passable choice for bedrooms. It's worth a look if you want something that can act as a fan or space heater, but its actual performance as an air purifier is pretty poor. It's somewhat noisy when running with its heater turned on, which is something to be aware of if you leave it running on colder nights.
- Also functions as a cooling fan or space heater.
- Automatic fan speed adjustment.
- Night mode dims display.
- Poor particle filtration performance.
- Low clean air delivery rate.
- Noisy operation when heater is turned on.
- Also functions as a cooling fan or space heater.
- Automatic fan speed adjustment.
- Poor particle filtration performance.
- Low clean air delivery rate.
- Noisy operation when heater is turned on.
Changelog
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Updated Mar 16, 2026:
We added a note about the Dyson Purifier Hot+Cool HP1's quieter operation in the Noise test box.
- Updated Feb 20, 2026: Version 1.1 of our air purifier testing methodology provides a more representative summary of unit performance, with a revised Particle Filtration Rate test conducted in a better-sealed environment and a more reliable means of generating consistently sized particulate matter. We've also included a parameter for the machine's maximum recommended room size. For a more detailed breakdown of the changes made, see our full changelog.
- Updated Nov 04, 2025: Version 1.0.2 of our Air Purifier Test Bench rectifies calculation errors in our existing Particle Filtration Rate test to provide more representative results of some units. For a more detailed breakdown of the changes made, see our full changelog.
- Updated Oct 31, 2024: Converted to Test Bench 1.0.1.
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Differences Between Sizes And Variants
The Dyson HP4B is available in only a single colorway: 'White/Silver.' You can see the label for our test unit here.
Let us know in the comments if you come across another variant of this machine.
Popular Air Purifier Comparisons
The Dyson HP4B is a combination air purifier, fan, and space heater that's best suited for small to medium-sized rooms. Like most other Dyson HP models, it isn't particularly impressive as an air purifier, with poor particle filtration performance and a low air cleaning rate. However, it does have some value as a cooling fan and space heater. The suite of onboard particle sensors also allows you to keep tabs on your home's air quality, even when you're away from home, thanks to its Wi-Fi connectivity.
The Dyson Purifier Hot+Cool HP07 is better than the Dyson Purifier Hot+Cool Purifying Heating Fan HP4B, which itself is simply a Costco-exclusive variant of the Dyson Purifier Hot+Cool Purifying Heating Fan HP04. The HP07 simply operates a little more quietly and has a higher clean air delivery rate.
Test Results
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