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.
- 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.
Performance Usages
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.
- Updated May 13, 2024: Review published.
Check Price
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
This device's display provides information on ambient particle quantities. You can cycle through a live view of room temperature and humidity, PM2.5 particle concentration, PM10 particle concentration, Volatile Organic Compound (VOC) level, and nitrogen dioxide level. The color of the indicator strip along the side of the display changes based on air quality.
- Green: Good
- Yellow: Fair
- Orange: Poor
- Red: Bad
This air purifier also comes with a remote control that allows you to change the air purifier's fan speed, adjust the fan's oscillation, cycle through particle count info, change the intensity of its heating element, or enable the device's Night mode, which dims the display, but doesn't shut it off, and sets the fan to its quietest setting. This remote is magnetized and is meant to be placed on top of the oval-shape fan when not in use.
This air purifier has a two-stage filter system comprising a HEPA filter and an Activated Carbon layer for locking in odors. However, the actual quantity of carbon isn't likely to be sufficient for locking in most VOCs.
The manufacturer doesn't issue any maintenance requirements for the filter system, but you should replace it every 12 months or whenever the device notifies you. You can buy a replacement here.