Blueair Blue Max 3250i vs Levoit Core 300S UK: The Small-Room Decision, Settled on Night-Time Data
Updated: October 2026 · Small-room bedroom comparison · Prices checked 21 Oct 2026
Sleep-Speed Shoot-Out Table
Most bedroom purifier comparisons use max-speed specs. That is the wrong data point — nobody sleeps next to a purifier running at maximum. The table below uses sleep-speed data only. Where manufacturers have not published sleep-speed CADR figures, that is stated explicitly rather than estimated.
| Metric | Blueair Blue Max 3250i | Levoit Core 300S |
|---|---|---|
| Noise at sleep speed | 18 dB ▲ quieter | 24 dB |
| CADR at sleep speed | Not published | Not published |
| Max CADR | 239 m³/h ▲ higher | 246 m³/h (conv. AHAM 145 × 1.699) |
| Room coverage (3 ACH) | 33 m² ▲ larger | 12 m² |
| Filter/year | £70.00 | £39.98 ▲ cheaper |
| 3-year total (TCO) | £403.38 | £230.70 ▲ saves £172.68 |
| Pre-filter | Fabric (machine-washable) ▲ | None separate |
| UK street price | £129.00 | £84.99 |
CADR at sleep speed not published by either manufacturer — only max-speed CADR is available. 3-yr TCO = unit price + (annual running cost × 3). Electricity at 24.5p/kWh. Blueair CADR manufacturer m³/h; Levoit CADR converted from AHAM CFM.
The Noise Difference: 18 dB vs 24 dB
Unlike the old Blueair 3210 comparison (where the 26 dB vs 24 dB gap was marginal), the 3250i's 18 dB is a meaningful step. A 6 dB reduction is perceived as roughly half as loud. At 18 dB, the 3250i produces a level that most people cannot consciously perceive in a quiet bedroom. At 24 dB, the Core 300S is already excellent — but measurably present. If you are a light sleeper or work night shifts, the 6 dB gap matters.
3-Year TCO Comparison
The 3250i's improved economics over the old Blueair 3210 come from its lower filter price: £35/unit vs £49.99 previously. Two filters per year at £35 = £70/yr, down from £99.98/yr. The Core 300S still wins on total cost.
| Cost item | Blueair Blue Max 3250i | Levoit Core 300S |
|---|---|---|
| Unit price | £129.00 | £84.99 |
| Electricity/yr (12h/day, conf.) | £21.46 | £8.59 |
| Filter/yr | £70.00 | £39.98 |
| Annual running cost | £91.46 | £48.57 |
| 3-year total (TCO) | £403.38 | £230.70 |
Note on Blueair 3250i electricity: The watts_typical figure (20W) is confirmed by the blueair.co.uk manufacturer page. Verify current filter prices before purchasing — the £35/filter figure reflects prices at 21 Oct 2026.
Pre-Filter: Blueair's Genuine Advantage
The Blueair Blue Max 3250i includes a machine-washable fabric pre-filter that captures large particles — pet hair, visible dust, lint — before they reach the main filter. The pre-filter can be removed, washed, and air-dried. The Levoit Core 300S has no separate washable pre-filter. In high-dust or pet-hair households, the Blueair pre-filter extends main filter life and is a genuine maintenance advantage.
Verdict
Three honest conclusions:
- 3-year TCO: Core 300S wins by £172.68 (£230.70 vs £403.38). A decisive gap driven by filter and electricity cost.
- Sleep noise: Blueair 3250i wins by 6 dB (18 dB vs 24 dB). Both are excellent, but 18 dB is genuinely inaudible in a typical bedroom. If silence is the priority, the 3250i is the stronger choice.
- Room coverage: 3250i wins substantially (33 m² vs 12 m²) — relevant if you want to run the unit in a medium-sized room as well as a bedroom.
For most UK buyers choosing a bedroom purifier under £150, the Core 300S is the stronger all-round choice on total cost. The Blueair 3250i is worth its £44.01 premium if near-silence at sleep speed (18 dB) or larger room coverage is genuinely important to your household.
Related: Best air purifiers for bedroom UK