Dreo
Dreo HM713S
Dreo publishes 500 mL/hr for this one, which is 3.17 gallons a day and puts it in the same real-output bracket as Levoit's LV600S at a slightly lower price. It also keeps the demineralisation cartridge, so unlike the Levoit it can run tap water without decorating the room. The 550 sq ft claim is close to what 3.17 gal/day actually supports - around 780 by the psychrometrics - making this one of the few portable ultrasonics whose room-size number is conservative rather than aspirational. The catch is the same as every hybrid: at the output that justifies the claim, the 6-litre tank is empty in about twelve hours.
The room-size claim, reconciled
781 sq ft supported · box says 550 sq ft
The 550 sq ft on the box is what the winter load calculation supports for this output — one of 18 units here whose claim lands within 5% of its own published rate.
Holding 550 sq ft takes about 2.23 gal/day, which drains this 1.59-gallon tank in roughly 17 hr — against the 60 hours Dreo advertises, which is measured at the lowest setting.
What a year costs
demineralisation cartridge three-pack around $18, changed every two months in season. Electricity assumes the rated 300 W for 12 hours a day across a 150-day heating season at 16¢ per kilowatt-hour.
Specifications
Maintenance profile
- Top fill
- Yes
- Replaceable media
- Demineralisation cartridge
Facts, not a score. Which of these matter depends entirely on whether the unit ends up somewhere you will actually clean it.
Features
- 500 mL/hr published output
- Warm and cool mist
- 6L top-fill tank
- Demineralisation cartridge included
- Humidity sensor and auto mode
- Dreo app
Pros
- One of the few ultrasonics whose published coverage claim is conservative against its own published output
- Demineralisation cartridge plus a real output figure is a rare combination at this price
- Warm mist and 3.17 gal/day capability in a unit that still fits on a side table
- Owners moving from a 4L unit describe it as the first one that changed the hygrometer reading
Cons
- Twelve hours of tank at full output, against the 60-hour low-setting claim
- The warm setting is what makes it expensive to run; cool mist costs roughly a tenth as much
- Cartridge replacement every two months is more often than most competitors ask
- No aroma tray, which buyers coming from the 512S notice
What owners say
Summarised from owner discussions and long-form owner reviews. Nobody here has used this unit.
The six-litre hybrid in Dreo's line, and one of the few portable ultrasonics whose coverage claim is conservative against its own published output. That combination — a real 500 mL/hr figure plus a demineralisation cartridge in the box — is unusual at this price and is the reason it stands up.
Owner accounts are practical rather than enthusiastic. People with a deviated septum or persistent congestion describe running it at a high target overnight and being able to breathe clearly, which is the use case it gets bought for. The cartridge is the part that makes tap water viable and the part you keep buying. As with every hybrid, the warm setting is the expensive one to run and the figure that empties the tank fastest.
What owners like
- Owners with a deviated septum or chronic congestion describe it as the unit that lets them breathe through both nostrils overnight
- The demineralisation cartridge clicks directly into the water path, so it is designed in rather than sold as an afterthought
- Warm mist option, real published output, and app control at a price below the equivalent Levoit
- Quiet enough to sit beside a desk and be forgotten
Common complaints
- Cartridges every month or two are a recurring cost, and owners on hard water report needing them at the short end of that range
- The warm setting draws an order of magnitude more power than cool mist
- Twelve hours of tank at the output that justifies the room-size claim, against the sixty advertised
- No aroma tray, which owners coming from the cheaper 512S notice
Questions owners ask
Can I use tap water?
Is the coverage claim realistic?
Warm or cool mist?
Dreo HM713S, head to head
Looked at alongside it
More from Dreo →
Dreo
Dreo HM717S
Eight litres, warm and cool mist, a published 500 mL/hr, and a demineralisation cartridge - on paper the most complete portable in Dreo's line. The extra two litres over the HM713S buy about four more hours at full output rather than the twenty the runtime figures suggest, because the 80-hour number is again the lowest setting. Where it genuinely earns the money is the middle: run it on auto in a 400 sq ft bedroom and it will go two or three nights between fills without a chilly mist or a dusty dresser.
781 sq ft supported · box says 600 sq ft
Dreo
Dreo HM512S
A litre more tank than the HM311S and a bigger room-size claim, from the same playbook: demineralisation cartridge in the box, humidity sensor, app, top fill. The 500 sq ft on the listing is the least defensible number Dreo publishes - that room calls for about 2 gallons a day, which would take the 5-litre tank down in roughly 16 hours against the 42 advertised. Treat it as a 250-300 sq ft machine and it is a good one. Against the HM311S it buys a litre of water and an aroma tray for $25; against Levoit's Classic 300S at a similar price it buys the demineralisation cartridge Levoit charges extra for, and gives up the longer-established app.
185 sq ft supported · box says 500 sq ft
Dreo
Dreo HM311S
Dreo does the thing most ultrasonic makers leave to a separate accessory listing: it ships a demineralisation cartridge and tells you when to change it. That single decision is why the HM311S sits in the no-white-dust filter on this site while several pricier ultrasonics do not. The rest is a competent $50 bedroom unit - 4-litre top-fill tank, real humidity sensor, app, 28 dB. Independent testing found it better suited to rooms under about 200 square feet than the 300 on the box, which is roughly where the arithmetic lands too: 300 sq ft wants 1.2 gallons a day and would drain the tank in about 21 hours rather than 32.
195 sq ft supported · box says 300 sq ft