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PuroAir 240 vs 400 is a classic “same brand, different scale” decision — and the right choice comes down to room size, layout, and how much air you truly need cleaned at once.
Verdict:
👉 Choose the PuroAir 240 if you’re cleaning a bedroom, nursery, office, or apartment room.
👉 Choose the PuroAir 400 if you need whole-room or open-concept coverage and want fewer units running at once.
Both deliver true HEPA performance. The difference is how much air they can realistically handle.
PuroAir 240 vs 400: Side-by-Side Comparison
Feature | ||
|---|---|---|
 |  | |
Best For | Bedrooms, nurseries, offices | Living rooms, open spaces |
Coverage Area | Small–medium rooms | Large rooms |
HEPA Filtration | Yes (medical-grade HEPA) | Yes (medical-grade HEPA) |
Airflow Power | Moderate | Strong |
Noise Level | Very quiet on low | Quiet on low, louder on high |
Physical Size | Compact | Larger footprint |
Ideal Placement | Nightstands, corners, desks | Floor placement, open areas |
Energy Use | Lower | Slightly higher |
Best Use Case | Single-room air quality | Whole-room air turnover |
Price |  | |
Quick Snapshot: PuroAir 400 vs PuroAir 240
PuroAir 240
- Best for: Bedrooms, nurseries, offices
- Coverage: Small–medium rooms
- Footprint: Compact, easy to place
- Biggest win: Affordable, quiet, efficient
PuroAir 400
- Best for: Living rooms, open layouts, large spaces
- Coverage: Large rooms
- Footprint: Larger, heavier
- Biggest win: Stronger airflow, faster whole-room cleaning
What Actually Matters When Choosing Between Them
Most comparison articles stop at square footage. That’s not enough.
Here’s what actually changes your experience:
1. Room Layout Beats Room Size
An open living room with vaulted ceilings behaves very differently than a closed bedroom — even if the square footage looks similar on paper.
- Closed rooms → 240 performs beautifully
- Open layouts → 400 keeps up without strain
2. Noise Over Time
Both are quiet on low and medium settings.
The difference shows up when you need high fan speed.
- 240: Fine for sleeping on low
- 400: More noticeable on high, but cleans faster
3. How Many Units You’ll Need
Two 240s vs one 400 is a real consideration.
- Multiple rooms → multiple 240s often make more sense
- One big shared space → one 400 is cleaner and simpler
Feature | ||
|---|---|---|
| | |
Best For | Bedrooms, nurseries, offices | Living rooms, open spaces |
Coverage Area | Small–medium rooms | Large rooms |
HEPA Filtration | Yes (medical-grade HEPA) | Yes (medical-grade HEPA) |
Airflow Power | Moderate | Strong |
Noise Level | Very quiet on low | Quiet on low, louder on high |
Physical Size | Compact | Larger footprint |
Ideal Placement | Nightstands, corners, desks | Floor placement, open areas |
Energy Use | Lower | Slightly higher |
Best Use Case | Single-room air quality | Whole-room air turnover |
Price | | |
Real-World Performance Differences
Allergies & Dust
Both units trap pollen, dust, and dander extremely well.
The 400 just does it faster in larger spaces.
Pets
- One dog in a bedroom → 240 is enough
- Multiple pets in shared space → 400 keeps odors and dander down better
Smoke & Cooking Smells
The 400 clears lingering odors faster due to higher air exchange.
The 240 still works — it just needs more time.
Pros & Cons
PuroAir 240 — Pros
- Excellent value for bedrooms
- Very quiet for sleep
- Compact and unobtrusive
- Lower energy usage
PuroAir 240 — Cons
- Not ideal for large or open rooms
- Slower odor removal in big spaces
PuroAir 400 — Pros
- Strong airflow and faster purification
- Better for open layouts
- Fewer units needed for large homes
PuroAir 400 — Cons
- Larger and heavier
- Higher upfront cost
- Louder at top speed
Who Should Buy Which?
Choose the PuroAir 240 if:
- You want cleaner air while sleeping
- You’re buying for a nursery or child’s room
- You prefer quiet operation over raw power
- You’ll place units in multiple rooms
Choose the PuroAir 400 if:
- Your living space is open or oversized
- You want faster air turnover
- You’d rather run one strong unit than several smaller ones
- Cooking smells, pets, or smoke linger easily in your home
FAQs –
Is the PuroAir 400 stronger than the 240?
Yes. The 400 moves more air per hour, making it better for large or open rooms.
Can I use the PuroAir 240 in a living room?
You can, but it works best in smaller enclosed spaces. Large living rooms benefit more from the 400.
Are the filters the same?
Both use medical-grade HEPA filtration, but the filter size and airflow capacity differ.
Which one is better for babies or nurseries?
The 240 is usually the better choice due to quieter operation and smaller room focus.
Do I need two 240s instead of one 400?
Sometimes, yes. Multiple closed rooms often benefit more from separate 240 units.
Final Take
The PuroAir 240 vs 400 decision isn’t about which is “better.”
It’s about scale.
- Small, quiet, personal spaces → PuroAir 240
- Big, shared, open spaces → PuroAir 400
Choose the purifier that matches how your home actually breathes — not just the numbers on the box.
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About the Author
Written by HappyHomeNerd — your trusted guide for smart home reviews, troubleshooting, and everyday tech fixes. Visit HappyHomeNerd for more expert tips and product breakdowns.