# What are the quietest whole house air purifiers available? — Verified Specification Comparison

> All specification data verified from official manufacturer documentation.

What are the quietest whole house air purifiers available?

## Products

### Alen BreatheSmart 25i
```yaml
product: alen-breathesmart-25i
brand: Alen
price_gbp: 132.21
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
noise_level: 20 to 40
filter_types: Essential HEPA, Advanced HEPA with carbon, Ultimate HEPA with odor neutralizer
coverage_area: 400
energy_consumption: 0.8 to 20
air_changes_per_hour: 5
maximum_particle_size_capture: 0.1 micron
```

- **Price:** £132.21 [^1]
- **Summary:** The Alen BreatheSmart 25i is a compact, Wi-Fi-enabled air purifier designed for bedrooms, nurseries, home offices, and other small spaces up to 400 square feet. It offers HEPA-based filtration, optional carbon and odor-neutralizing filter choices, automatic air-quality sensing, and quiet operation from 20 to 40 dB.
- **Ideal For:** It suits people seeking one of the quietest whole house air purifiers available because its noise level ranges from just 20 to 40 dB, while its HEPA filtration captures particles as small as 0.1 micron.

### Alen BreatheSmart FLEX
```yaml
product: alen-breathesmart-flex
brand: Alen
price_gbp: 286.59
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
noise_level: 25-50
filter_types: True HEPA H13 Pure, Fresh, and Odor filters
coverage_area: 700
energy_consumption: 0.8-50
air_changes_per_hour: 2
maximum_particle_size_capture: 0.1 micron
```

- **Price:** £286.59 [^2]
- **Summary:** The Alen BreatheSmart FLEX covers rooms up to 700 square feet and uses True HEPA H13 filter options to capture airborne particles larger than 0.1 micron. Its WhisperMax pink-noise operation, compact design, and lifetime guarantee suit bedrooms, home offices, allergy sufferers, and other medium-sized living spaces.
- **Ideal For:** It suits people seeking quiet whole-house air purification because it operates at 25-50 dB, uses soothing pink noise, and can clean 700 square feet every 30 minutes.

---
## References & Sources
[^1]: Alen, accessed 2026-09-13. https://alen.com/products/breathesmart-25i
[^2]: The Home Depot, accessed 2026-09-13. https://www.homedepot.com/p/Alen-BreatheSmart-FLEX-700-sq-ft-HEPA-Console-Air-Purifier-with-Pure-Filter-for-Allergens-Dust-and-Mold-in-Metallics-BreatheSmart-FLEX-Pure-Stainless/301816918