Humidifier 311 4L vs Dreo HM524S Smart Humidifier
Buy the Dreo HM524S if you want a bigger tank, more coverage and app alerts; buy the Humidifier 311 if you want to spend less. On November 3, 2026 the 311 is $39.99 at Amazon and the HM524S is $59.99 at Dreo, a $20 gap. Both are quiet 28 dB ultrasonic cool-mist units, so the choice comes down to tank size, room size and smart features.
Today the Humidifier 311 4L costs $20.00 less at its best price.
Ask our shopping agent
Humidifier 311 4L
4.7Choose the Humidifier 311 if you need a cheap, quiet bedroom humidifier and 4 L is enough for one room.
- Lowest price of the two at $39.99
- 28 dB, quiet enough for a bedroom
- Top-fill tank is easy to refill and clean
- App control, timer and auto mode at a budget price
- 4 L tank runs dry faster; buyers report about 12–24 hours in dry climates
What separates them
| Humidifier 311 4L | Dreo HM524S Smart Humidifier | |
|---|---|---|
| Price (November 3, 2026) | $39.99 at Amazon | $59.99 at Dreo |
| Tank capacity | 4 L | 6 L |
| Coverage | 300 ft² | 500 ft² |
| Claimed runtime | Up to 32–36 hours | Up to 60 hours |
| Noise | 28 dB | 28 dB |
| Humidistat and auto mode | Yes, ±control via app | Yes, holds within ±5% |
| App and voice control | Yes, plus timer scheduling | Yes, with low-water and cleaning alerts |
| Mist output |
Price history
- Humidifier 311 4L: lowest $39.99 on Nov 4 at Amazon.
- Dreo HM524S Smart Humidifier: lowest $59.99 on Nov 4 at Dreo.
Prices at every store
Humidifier 311 4L
- DREONew
In stockReturn policy
$39.99Verified - AmazonNew
Availability unknown
As an Amazon Associate, Deal.ai earns from qualifying purchases.
$39.99Free shippingObserved at 8:25 PM
Also available at
Dreo HM524S Smart Humidifier
- DreoNew
In stock
$59.99Free shippingObserved at 8:25 PM - AmazonNew
Availability unknown
As an Amazon Associate, Deal.ai earns from qualifying purchases.
$62.29Free shippingObserved at 8:25 PM - eBayPre-owned
Out of stockSold by econsignments
$21.99+ $17.91 shippingObserved at 8:25 PM
Also available at
Specs compared
| Spec | Humidifier 311 4L | Dreo HM524S Smart Humidifier |
|---|---|---|
| Humidification Type | Ultrasonic | Ultrasonic |
| Coverage Area | 300 ft² | 500 Square Feet |
| Water Tank Capacity | 5 L | 6 L |
| Volume | 5 L | 6 L |
| Automatic Shutoff | Yes (stops when desired humidity is reached) | Yes |
| Timer | Yes (scheduling via app) | Yes |
| Functionality Type | Humidifier | Humidifier |
| Humidistat | Yes (intelligent humidity control) | Yes |
| Mist Temperature | Cool mist | Cool mist |
| Mist Type | Ultrasonic | Ultrasonic |
What reviewers say
Humidifier 311 4L
Rated 4.7 out of 5 from 310 ratings. Owners mostly praise how quiet it is, how easy it is to fill and clean, and how it helps with dry mouth and congestion. Complaints center on runtime falling short of the claim, early failures, and the lack of separate replacement tanks.
- Silent enough for night use
- Easy top-fill and easy cleaning
- Helps with dry mouth, coughs and congestion
- Mist does not pool on furniture
- Runs closer to 24 hours than 32, and under 12 for one owner
- One unit stopped working after about 3 months
- One unit arrived with a crack
- Replacement tanks not sold separately
Dreo HM524S Smart Humidifier
Owners rate it highly, with 4.9 out of 5 from 195 ratings, and most praise the quiet operation, easy cleaning and accurate humidity control. The main complaints are that the 60-hour runtime is overstated and that white dust can build up on furniture.
Questions and answers
- Which is better for a large bedroom?
- The HM524S. It covers up to 500 ft² and holds 6 L, against 300 ft² and 4 L for the 311.
- Is the HM524S worth $20 more?
- Yes if you refill often or want app alerts. The 311 is the better value for a small room on a budget.
- Which one is quieter?
- They tie. Both are rated 28 dB, and buyers of both call them near-silent at night.
- How long does each run on a full tank?
- Dreo claims up to 32–36 hours for the 311 and up to 60 for the HM524S. Buyers of both report far shorter runs, around 12–24 hours.
- Do either need distilled water?
- Yes. Both are ultrasonic and can leave white mineral dust, so use distilled water, especially with the HM524S.
- Which is easier to clean?
- Both have top-fill, removable tanks. The HM524S has modular parts, but neither is dishwasher safe.