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ALTERNATIVES
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Scored using Air Purifiers Methodology v1.0
Air Purifiers Methodology v1.0
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Products in this category are scored under Frontum Air Purifiers Methodology v1.0: technical specifications plus authentic consumer ratings, with 0% commercial bias.
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Alen 45i Pure Carbon Review | 45 Data compared

Avg. price:~£380Max. CADR:245 m³/hMaximum room area:74 m²Maximum noise level:49 dBHEPA filter:yesWeight:6.8 kg

Alen 45i Pure Carbon Review: Compare 45 technical specifications and user reviews to see how this product ranks in the Air Purifiers category and whether it is worth buying.

Alen 45i Pure Carbon
7.2/10

Overall score

Score
7.2/ 10
✕
What it is
An overall evaluation of products in the Air Purifiers category, based on technical analysis and user reviews.
When it matters
When you need a quick reference for identifying the best products in the Air Purifiers category.
Score distribution
â–¼
<55-66-77-88-99-10
â–² Better than 60% of models
Score components

80%

6.8

Technical score

20%

8.8

User score

â–²Better than 60% of air purifiers
7.2

Value for money

Value for money
7.2/ 10
✕
What it is
An indicator that combines the overall score of products in the Air Purifiers category with their prices.
When it matters
When you are comparing products in the Air Purifiers category and want a good balance between quality and price.
Score distribution
â–¼
<55-66-77-88-99-10
â–¼ Worse than 73% of models
Score components

70%

7.2

Overall score

30%

7.2

Price

â–¼Worse than 73%
6.8

Technical score

Technical score
6.8/ 10
✕
What it is
An assessment of technical performance for products in the Air Purifiers category across these key areas: Performance, Features, Design.
When it matters
When you want to compare products in the Air Purifiers category by technical performance, specifications, and available features.
Score distribution
â–¼
<55-66-77-88-99-10
â–² Better than 54% of models
Score components

50%

6.0

Performance

40%

7.9

Features

10%

6.2

Design

â–²Better than 54%
8.8

User score

User score
8.8/ 10
✕
What it is
A rating that combines user reviews with the total review volume for products in the Air Purifiers category.
When it matters
When you want to know how products in the Air Purifiers category perform in everyday use and how reliable owners find them over time.
Score distribution
â–¼
<55-66-77-88-99-10
â–² Better than 84% of models
Score components

70%

9.4

User ratings

30%

7.5

Number of reviews

Based on 1,150 buyer reviews from online shops.
Read buyer reviews on Amazon →
How we calculate this
User ratings – average star rating across all shop listings, weighted by how many reviews each has, on a 1–10 scale.
Number of reviews – how many buyer reviews the product has, on a logarithmic scale; the 8% most-reviewed models in the category get 10.
â–²Better than 84%
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Best prices
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Best rankings
Available: ranking among products currently available (including other versions of this product).All: ranking among all products in the database.
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Technical Specifications of air purifier Alen 45i Pure Carbon

Technical score
Technical score
6.8/ 10
✕
What it is
An assessment of technical performance for products in the Air Purifiers category across these key areas: Performance, Features, Design.
When it matters
When you want to compare products in the Air Purifiers category by technical performance, specifications, and available features.
Score distribution
â–¼
<55-66-77-88-99-10
â–² Better than 54% of models
Score components:

50%

6.0

Performance

40%

7.9

Features

10%

6.2

Design

6.8
User score
User score
8.8/ 10
✕
What it is
A rating that combines user reviews with the total review volume for products in the Air Purifiers category.
When it matters
When you want to know how products in the Air Purifiers category perform in everyday use and how reliable owners find them over time.
Score distribution
â–¼
<55-66-77-88-99-10
â–² Better than 84% of models
Score components

70%

9.4

User ratings

30%

7.5

Number of reviews

Based on 1,150 buyer reviews from online shops.
Read buyer reviews on Amazon →
How we calculate this
User ratings – average star rating across all shop listings, weighted by how many reviews each has, on a 1–10 scale.
Number of reviews – how many buyer reviews the product has, on a logarithmic scale; the 8% most-reviewed models in the category get 10.
8.8
Popularity
Popularity
7.5/ 10
✕
What it is
An indicator based on the number of reviews received by products in the Air Purifiers category.
When it matters
When you prefer products in the Air Purifiers category that have been chosen and reviewed by many other buyers.
Score distribution
â–¼
<55-66-77-88-99-10
â–² Better than 65% of models
Popularity:
Alen 45i Pure Carbon has a popularity score of 7.5 points, which is higher than 65% of products in this category.
7.5
Value for money
Value for money
7.2/ 10
✕
What it is
An indicator that combines the overall score of products in the Air Purifiers category with their prices.
When it matters
When you are comparing products in the Air Purifiers category and want a good balance between quality and price.
Score distribution
â–¼
<55-66-77-88-99-10
â–¼ Worse than 73% of models
Score components:

70%

7.2

Overall score

30%

7.2

Price

7.2
Power
50 W
Market range: <10 W – >68 W
This air purifier has a power output of 50 W, which is higher than that of 68.5% of air purifiers and the same as that of 4.4% of air purifiers.
Max. CADR
245 m³/h
Market range: <100 m³/h – >515 m³/h
This air purifier delivers a CADR of 245 m³/h, which is higher than that of 51.6% of air purifiers.
Maximum room area
74 m²
Market range: <20 m² – >130 m²
This air purifier covers up to 74 m², which is larger than 67.2% of air purifiers.
N. of speeds
4
Market range: <3 – >5
This air purifier offers 4 fan speeds, which is more than 55.9% of air purifiers and the same as 25.1% of air purifiers.
Maximum noise level
49 dB
Market range: <32 dB – >61 dB
This air purifier reaches 49 dB at maximum speed, which is quieter than 73.8% of air purifiers and the same as 7.3% of air purifiers.
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Air quality indicator
yes
This air purifier has an air-quality indicator. This feature is present on 65.4% of air purifiers.
Continuous purification
yes
This air purifier supports continuous purification. This feature is present on 86.3% of air purifiers.
Auto mode
yes
This air purifier has auto mode. This feature is present on 67% of air purifiers.
Timer
no
This air purifier does not have a timer. This feature is present on 75% of air purifiers.
Maximum timer
N/A
Show more
Color
grey
Material
fiberglass
Display
yes
This air purifier has a display. This feature is present on 51.1% of air purifiers.
Display position
top
Control type
touch
Show more

Alen 45i Pure Carbon vs the average air purifier

246810TotalPerformanceFeaturesDesign
  • Has a child lock
    This air purifier has a child lock; the average air purifier does not.
  • 25 m² larger room area
    This air purifier covers a larger room area than the average air purifier (74 m² vs 49 m²).
    74 m² vs 49 m²
  • 1 more fan speeds
    This air purifier provides more fan speed settings than the average air purifier (4 vs 3).
    4 vs 3
  • 4 dB lower maximum noise level
    This air purifier runs quieter at maximum speed than the average air purifier (49 dB vs 53 dB).
    49 dB vs 53 dB
  • Has an ionizer
    This air purifier has an ionizer; the average air purifier does not.
  • 0.5 m longer power cord
    This air purifier features a longer power cord than the average air purifier (2.3 m vs 1.8 m).
    2.3 m vs 1.8 m
  • 12.5 W higher power
    This air purifier has a higher power output than the average air purifier (50 W vs 37.5 W).
    50 W vs 37.5 W
  • Has a handle
    This air purifier has a handle; the average air purifier does not.
  • 9.3% higher user score
    User score
    8.8/ 10
    ✕
    What it is
    A rating that combines user reviews with the total review volume for products in the Air Purifiers category.
    When it matters
    When you want to know how products in the Air Purifiers category perform in everyday use and how reliable owners find them over time.
    Score distribution
    â–¼
    â–¼
    <55-66-77-88-99-10
    Alen 45i Pure Carbon
    the average air purifier
    Alen 45i Pure Carbon has a higher user score than the average air purifier (8.80 vs 8.048).
    8.8 vs 8.05
  • 11.8% more popular
    Alen 45i Pure Carbon is more popular than the average air purifier (7.45 vs 6.7).
    7.45 vs 6.67
  • 25 m² larger room area
    This air purifier covers a larger room area than the average air purifier (74 m² vs 49 m²).
    74 m² vs 49 m²
  • 1 more fan speeds
    This air purifier provides more fan speed settings than the average air purifier (4 vs 3).
    4 vs 3
  • 4 dB lower maximum noise level
    This air purifier runs quieter at maximum speed than the average air purifier (49 dB vs 53 dB).
    49 dB vs 53 dB
  • 12.5 W higher power
    This air purifier has a higher power output than the average air purifier (50 W vs 37.5 W).
    50 W vs 37.5 W
  • 2.1% higher CADR
    This air purifier provides a higher clean air delivery rate than the average air purifier (245 m³/h vs 240 m³/h).
    245 m³/h vs 240 m³/h
  • Has a child lock
    This air purifier has a child lock; the average air purifier does not.
  • Has an ionizer
    This air purifier has an ionizer; the average air purifier does not.
  • 0.5 m longer power cord
    This air purifier features a longer power cord than the average air purifier (2.3 m vs 1.8 m).
    2.3 m vs 1.8 m
  • Has a handle
    This air purifier has a handle; the average air purifier does not.
  • 0.5 cm shallower depth
    This air purifier is shallower than the average air purifier (21.5 cm vs 22 cm).
    21.5 cm vs 22 cm
  • No washable prefilter
    This air purifier does not have a washable prefilter; the average air purifier does.
  • No timer
    This air purifier does not have a timer; the average air purifier does.
  • 0.07 % percentage points lower bacteria elimination
    This air purifier achieves lower certified bacteria elimination than the average air purifier (99.9 % vs 99.97 %).
    99.9 % vs 99.97 %
  • 10.8 cm wider width
    This air purifier is wider than the average air purifier (38.1 cm vs 27.3 cm).
    38.1 cm vs 27.3 cm
  • 48.8% higher weight
    This air purifier is heavier than the average air purifier (6.8 kg vs 4.57 kg).
    6.8 kg vs 4.57 kg
  • 13.5 cm taller height
    This air purifier is taller than the average air purifier (63.5 cm vs 50 cm).
    63.5 cm vs 50 cm
  • 2.71x more expensive
    Alen 45i Pure Carbon is more expensive than the average air purifier (£380 vs £140).
    £380 vs £140
  • 4.5% worse value for money
    Alen 45i Pure Carbon offers worse value for money than the average air purifier (7.19 vs 7.5).
    7.19 vs 7.52
  • 2.71x more expensive
    Alen 45i Pure Carbon is more expensive than the average air purifier (£380 vs £140).
    £380 vs £140
  • 4.5% worse value for money
    Alen 45i Pure Carbon offers worse value for money than the average air purifier (7.19 vs 7.5).
    7.19 vs 7.52
  • No washable prefilter
    This air purifier does not have a washable prefilter; the average air purifier does.
  • No timer
    This air purifier does not have a timer; the average air purifier does.
  • 0.07 % percentage points lower bacteria elimination
    This air purifier achieves lower certified bacteria elimination than the average air purifier (99.9 % vs 99.97 %).
    99.9 % vs 99.97 %
  • 10.8 cm wider width
    This air purifier is wider than the average air purifier (38.1 cm vs 27.3 cm).
    38.1 cm vs 27.3 cm
  • 48.8% higher weight
    This air purifier is heavier than the average air purifier (6.8 kg vs 4.57 kg).
    6.8 kg vs 4.57 kg
  • 13.5 cm taller height
    This air purifier is taller than the average air purifier (63.5 cm vs 50 cm).
    63.5 cm vs 50 cm
  • 69.4% larger external volume
    This air purifier has a larger overall volume than the average air purifier (52016 cm³ vs 30700.8 cm³).
    52,016.025 cm³ vs 30,700.8 cm³

Video reviews

Hands-on testing, unboxing, and real-world video evaluations

Expert reviews

In-depth analysis and verdict from leading tech publications

H
housefresh.com
17/12/2025
Summary of the review
Alen BreatheSmart 45i Air Purifier Review
T
techradar.com
11/04/2024
Summary of the review
Alen BreatheSmart 45i Comprehensive Air Purifier Review

Third-party reviews

Based on 1,150 buyer reviews from online shops.
Reviews last updated: August 2026 · How we calculate this
Read buyer reviews on Amazon →

What we like about Alen 45i Pure Carbon

  • Noticeably improves indoor air quality by reducing dust, dander, and allergens
  • Effectively neutralizes cooking, pet, and smoke odors when utilizing the specialized carbon filters
  • Runs very quietly on lower fan speeds and generates a soothing pink noise profile
  • Features an accurate SmartSensor auto-mode that automatically adjusts fan speeds based on real-time air quality
  • Includes a lifetime warranty option conditional on maintaining an active OEM filter subscription
  • Modern design aesthetics with customizable panel colors to match home decor
  • User-friendly control interface that features adjustable display brightness and a color-coded air quality indicator wheel

What we don't like about Alen 45i Pure Carbon

  • High upfront purchase price compared to competing air purifiers with similar CADR metrics
  • Ongoing financial commitment due to expensive proprietary replacement filters required for the warranty
  • The standard entry-level 'Pure' filter option lacks activated carbon and is ineffective against household odors
  • Mobile app setup can occasionally be glitchy, providing limited functionality beyond standard panel controls
  • Unit is somewhat bulky and heavy, making it less portable despite having a integrated handle

Verdict

The Alen BreatheSmart 45i with the Pure filter is a premium air purifier featuring a Clean Air Delivery Rate (CADR) of 255 CFM, designed to circulate air efficiently in spaces up to 800 square feet every 30 minutes. It features a medical-grade H13 True HEPA filtration system that removes 99.9% of airborne particles down to 0.1 microns, an ozone-free ionizer, and an intelligent laser sensor with a 5-color real-time air quality indicator light ring that drives its automated fan speed adjustments across 4 power settings (drawing between 1.1 to 50 watts). Key advantages include its ultra-quiet WhisperMax technology that generates soothing pink noise from 23 to 49 dB, a lifetime warranty with an active filter subscription, Energy Star certification, and a compact 15-pound frame with customizable front panels. However, the standard Pure filter configuration lacks a pelleted carbon element needed to neutralize volatile organic compounds (VOCs) and persistent odors, filter replacements can be relatively expensive, and the unit lacks a detailed numerical particle counter display on its panel.

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