# What is the most energy-efficient portable humidifier available? — Verified Specification Comparison

> All specification data verified from official manufacturer documentation.

What is the most energy-efficient portable humidifier available?

## Products

### PureGuardian H940AR
```yaml
product: pureguardian-h940ar
brand: PureGuardian
price_gbp: 14.69
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
output: 6436
capacity: 1893
humidistat: false
auto_shutoff: true
coverage_area: 350
```

- **Price:** £14.69 [^1]
- **Summary:** The PureGuardian H940AR is an ultrasonic cool-mist humidifier with a 0.5-gallon tank, aromatherapy tray, night light, Silver Clean protection, and up to 30 hours of operation on low speed. It suits small rooms, bedrooms, and users who want quiet operation and basic automatic shutoff without advanced humidity control.
- **Ideal For:** It suits energy-conscious users because its ultrasonic cool-mist technology provides 30 hours of operation on low speed from a 0.5-gallon tank and has no heating element, though it is not Energy Star certified.
- **Additional Sources:** [^2], [^3]

### Vicks VUL525
```yaml
product: vicks-vul525
brand: Vicks
price_gbp: 12.42
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
humidistat: false
noise_level: 39
auto_shutoff: true
coverage_area: 250
```

- **Price:** £12.42 [^4]
- **Summary:** The Vicks VUL525 is a compact ultrasonic cool-mist humidifier with a 1.8-litre tank, adjustable mist direction, quiet 39 dB operation, and VapoPad compatibility. It suits small bedrooms, nurseries, and personal spaces up to 250 square feet, with automatic shutoff for safety.
- **Ideal For:** It is a relatively energy-efficient choice because its ultrasonic design uses 21 watts while providing adjustable mist output for spaces up to 250 square feet.
- **Additional Sources:** [^5], [^6]

---
## References & Sources
[^1]: Guardian Technologies, accessed 2026-08-28. https://guardiantechnologies.com/products/h940-0-5-gallon-30-hour-ultrasonic-cool-mist-humidifier-by-pureguardianr-reg
[^2]: Home Depot, accessed 2026-08-28. https://www.homedepot.com/p/Pure-Guardian-0-5-gal-Ultrasonic-Cool-Mist-Humidifier-for-Rooms-up-to-350-sq-ft-in-Blue-White-30-Hour-Runtime-on-Low-Aromatherapy-H940AR/300353650
[^3]: Kohl's, accessed 2026-08-28. https://www.kohls.com/product/prd-3556230/pureguardian-30-hour-ultrasonic-cool-mist-humidifier.jsp
[^4]: Best Buy, accessed 2026-08-28. https://www.bestbuy.com/product/mini-filter-free-cool-mist-humidifier-small-room-variable-mist-control-works-with-vicks-vapopads-white/JC24TRQPPZ
[^5]: McGrocer, accessed 2026-08-28. https://mcgrocer.com/products/vicks-vul525-mini-cool-mist-ultrasonic-humidifier-1-8-litre-2026425667
[^6]: Pharmazone, accessed 2026-08-28. https://pharmazone.com/en-ae/products/vicks-humidifier-mini-cool-mist-1-8l-525e1