Top critical review
What this is, and what it isn't
April 17, 2018
This is a stylish modestly powered oscillating room fan with a fancy but small air purification capacity. It isn't an air conditioner, meaning it doesn't refrigerate the air it blows out. And it isn't nearly as much of an air purifier as regular purifiers of similar cost, ones that aren't also room fans.
I like the concept, a combination of style, fan and purifier. I was disappointed with the power, and I wish the filters could be bypassed so you could cool yourself without running air through the filters when they aren't needed, which could increase air flow. (You could run it with the filters removed, but it appears it would void your warranty--more on that below.)
It has great style and some nice features, so for people with different priorities, this may still be a fine choice.
The Dyson website and the box say this model, TP04, delivers an air flow of over 77 gallons per second, which is equivalent to 618 cubic feet per minute (cfm). Dyson customer service claims a higher number, 361 liters per second, which works out to 765 cfm.
Either way, this isn't a powerful fan compared to, say, a $50 16" oscillating pedestal fan, which might deliver up to twice as much air flow. My old $20 15" table fan is a lot more powerful. (Not that I would trade this one for it!)
It appears this has only a fraction of the filtering capacity of comparably-priced purifiers, and a little over half the capacity of a much cheaper purifier rated for the room size Dyson seems to think this fan is adequate for, 290 square feet. (I'll show the details at the end of the review.)
It appears Dyson thinks the fact that it has a fan to circulate the air better helps with the filtering, which is probably true. But it's not nearly enough to make up for the much smaller filtering capacity. If it was, they'd submit it for CADR certification (which is a pretty fair and widely recognized standard for comparing purifiers). You could use a regular pedestal or table fan with a regular purifier and get a similar air circulation effect with much better purification, though it wouldn't look as nice.
In practice what this means is that for the same money you could get a much larger space purified to the same standard, purify the same amount of space to a much higher standard, or operate a normal purifier at a lower, quieter setting to get the same amount of purification as you would with the Dyson at full power.
On the other hand, many of us don't need high levels of air purification, so a smaller amount will do.
Dyson customer service claims this fan has peak noise of 42.3 dB, which I knew was way off as soon as I turned it on. My Blueair 121 purifier, which pumps about two thirds as much air as this fan and is distinctly quieter, is rated to top out at 56. I'd say this one tops out at over 60 dB, which isn't bad at all, a lot better than my 15" table fan. The sound is a pleasant-enough white noise.
Of course the lower settings are what you normally use, and those are quieter. The lowest ones are very quiet, barely audible in a quiet room.
I think this is the coolest looking fan on the market.
350 degrees of oscillation, almost full circle, is more than most by a lot. The rotation is smooth, quiet, adjustable, and looks good. (You can supposedly customize it with the app, but I see no way to do that, and customer service can't explain it either.)
This has sensors that purport to tell you how much of various kinds pollutants are in the air, plus temperature and humidity. A composite air quality level shows by default on the 1-1/2" auto-bright LED screen on front, with a flurry of more particular graphics if some particular pollutant gets out of line. You can also check each pollutant level manually with the remote, or track them with the app and see them graphed over time. (I'm particularly proud of my NO2.)
Besides the graphics, the usefulness of the sensors is that when set to auto the fan adjusts the airflow to fit the amount of pollution.
The little display automatically dims in low light, but you can make it even dimmer/go off (depending on amount of ambient light) with night mode, which doesn't show the air quality graphics and limits auto mode to the lower fan speeds. You can use the app to manually select a higher fan speed in night mode.
Another nice feature is that you can reverse the air flow when you don't want it blowing toward you while the purifying is going on. Seems to work fine, you can hear the baffle shifting position when you switch.
Easy. The quick start guide is easy to follow, took less than five minutes to unpack and get going. Setting up the app requires name, email, when you purchased (to start the warranty), wifi password to connect to your wifi, nothing too invasive.
They answered several email questions pretty fast, in under an hour to under a day. They didn't always give accurate information, though.
Using the fan without the filters
The manual says "If the machine has been used without a filter in place or the filters have not been changed when prompted, blockages may occur." Then they show how to clean a blockage. If you're willing to risk it you could probably run it just as a very pricey fan without a filter, or with an improvised screen filter to help prevent blockage.
However, the warranty says, "Dyson shall not be liable for ... use not in accordance with the Dyson Operating Manual," which of course specifies use with filters.
Filters are nonwashable and are expected to be replaced about every six months. The machine lets you know when it's time to change, and you can check on the app to see a percentage of life left. I don't see them listed at the Dyson website yet, but that's normal for a new machine.
The electrical cord is almost 78" including the connectors, so over six feet long. The safety warnings in the manual say an extension cord isn't recommended (but if you get one that can handle the current I think you'll be fine).
I don't see any restrictions on how far it needs to be from walls or other objects, so it's not hard to find a place for.
Two years free repairs.
Made in Malysia.
Purification power details
This has a true HEPA particle filter, which is more than plenty fine for most household applications.
It also has a carbon filter to remove some kinds of noxious fumes and odors.
The Dyson website mysteriously says this fan circulates purified air through "the whole room," with a note that says, "Tested to Dyson internal method TM-003711 in a 290ft2 room and DTM801." I can't find any information on what that means, but it seems to mean Dyson thinks its purification is adequate for a 290-square-foot room.
As mentioned above, Dyson doesn't submit its machines for CADR certification. They're very sketchy about purifying power in other ways too, so customers are reduced to estimates based on what we do know.
One rough way to estimate the purification power of true HEPA filters is their size, since they meet the same HEPA standards per unit of surface area. The HEPA filter in this fan has "60% more HEPA medium" than previous Dyson models, which is encouraging. It's still a relatively small filter, though.
According to my measurements, including counting those pleats on the filters, the surface area of the TP04 HEPA filters total about:
10 square feet
That may seem like a lot, but other similarly-priced or cheaper air purifiers (Austin HealthMate Plus Junior, Blueair 405) have 30 and 38.5 square feet.
The HEPA filter for a much cheaper purifier rated for a 280-square-foot room (Blueair 205) has 18.5 square feet of HEPA surface area. I doubt 10 square feet will purify to the same level, even with the fan to circulate the air better.
For the carbon filter, it has "3x more carbon" than in previous Dyson models. Dyson doesn't say how much that is, but each of the two carbon filters weighs just over a half pound including the plastic frame, so the total weight of carbon in the two together is at most:
The comparably-priced purifiers mentioned above have 2.2 and 6.5 pounds.
The cheaper purifier rated for 280 square feet has 1.8 pounds.
Purification power is also closely tied to the amount of air filtered. Dyson doesn't say and its customer service won't tell how much air is filtered. It's not nearly the air flow mentioned above because of what Dyson calls the Air Multiplier, which seems to mean in simple words that as with other fans the air stream coming from the fan isn't only air pushed directly by the fan blades but also air that gets sucked along or "entrained" with the pushed air. (For the previous model of this fan, it appeared from tests that only a small portion of the advertised air flow was being filtered.)