Alen Air Purifiers: 6 Picks Ranked by Specs

Quick picks

Our 6 picks

1 Best overall

Alen BreatheSmart Large Room Air Purifier

Best for: Large rooms needing H13 filtration and smart sensors

Room Coverage

1,400 sq ft

Filter Type

H13 True HEPA

Air Quality Sensor

SmartSensor

Smart Connectivity

App

Target Pollutant

Pet Dander, Allergies, Dust

Control Method

App Control

View on Amazon: Alen BreatheSmart Large Room Air Purifier Affiliate link

The Alen BreatheSmart 35i is a compact air purifier designed for rooms up to 1,400 square feet. It uses an H13 HEPA filter to capture 99.9% of particles as small as 0.1 micron, including allergens and bacteria. The unit features a SmartSensor that adjusts fan speed based on air quality, indicated by color-coded rings. It operates quietly with pink noise for sleep support. This model suits those prioritizing filtration depth and automated air quality management in medium to large spaces.

Pros

• H13 HEPA filter captures particles down to 0.1 micron
• Covers up to 1,400 square feet
• SmartSensor adjusts fan speed with color-coded feedback
• Produces pink noise for sleep enhancement

Cons

• Smaller footprint than the 75i or 45i models
• Essential filter tier lacks advanced features of higher tiers
• No app or remote control mentioned in specifications

Good fit if

• You need strong filtration for a large bedroom or office
• You want automatic fan speed adjustment based on air quality
• You prefer quiet operation with sleep-friendly noise profiles

Skip if

• You require coverage for spaces larger than 1,400 square feet
• You need smart home integration or app control
• You prefer the highest-tier filtration with extra features

Verdict: Alen BreatheSmart 35i Essential delivers robust H13 filtration and smart automation for medium-large rooms, making it a solid choice for allergy sufferers seeking quiet, automated air cleaning without app complexity.

2 Also great

Alen BreatheSmart 25i HEPA Air Purifier

Best for: small rooms and bedrooms up to 800 sq ft

Room Coverage

Up to 800 sq ft

Filter Type

H13 True HEPA

Air Quality Sensor

SmartSensor, color-coded rings

Smart Connectivity

App

Target Pollutant

Pet Dander, Allergies, Dust

Control Method

App Control

View on Amazon: Alen BreatheSmart 25i HEPA Air Purifier Affiliate link

The Alen BreatheSmart 25i is a compact air purifier designed for rooms up to 800 square feet. It uses an H13 HEPA filter to capture 99.9% of particles as small as 0.1 micron. The unit features a SmartSensor that adjusts fan speed based on air quality, indicated by color-coded rings. Weighing just 8 pounds, it fits easily in bedrooms or home offices. Its quiet operation and pink noise emission support better sleep.

Pros

• H13 HEPA filter captures 99.9% of particles down to 0.1 micron
• Covers rooms up to 800 square feet efficiently
• SmartSensor adjusts fan speed with color-coded air quality feedback
• Ultra-quiet operation emits pink noise for sleep support

Cons

• Smaller room coverage compared to larger Alen models like the 35i or 75i
• Limited to Essential filter size option in this specific configuration
• No remote control or mobile app mentioned in specifications

Good fit if

• You need a purifier for a bedroom or small office under 800 sq ft
• You prioritize quiet operation and sleep-friendly pink noise
• You want automatic air quality adjustment via SmartSensor

Skip if

• You need to purify large living rooms exceeding 800 sq ft
• You require app control or remote operation features
• You prefer the highest filtration level available in the Alen lineup

Verdict: Alen BreatheSmart 25i HEPA Purifier is a quiet, space-saving option for small rooms where sleep quality and automatic air monitoring matter most.

3 Also great

Alen BreatheSmart HEPA Air Purifier

Best for: Large rooms needing quiet auto purification

Room Coverage

1,900 sq ft

Filter Type

True HEPA

Air Quality Sensor

SmartSensor

Smart Connectivity

App

Target Pollutant

Odor, Smoke, Pet Dander, Allergies, Dust, Mold

Control Method

App Control

View on Amazon: Alen BreatheSmart HEPA Air Purifier Affiliate link

The Alen 45i is a large-capacity air purifier covering 1,900 square feet. It uses a HEPA filter to capture particles as small as 0.1 micron. SmartSensor technology adjusts fan speed based on real-time air quality. The unit operates quietly with pink noise to support sleep. It is designed for large living rooms or bedrooms where high air exchange is needed.

Pros

• Covers 1,900 square feet per hour
• HEPA filter captures 0.1 micron particles
• SmartSensor adjusts fan speed automatically
• Pink noise mode supports sleep

Cons

• Only includes Auto Mode operation
• No manual fan speed settings listed
• Larger footprint than smaller Alen models

Good fit if

• You need coverage for a large room up to 1,900 sq ft
• You prefer automatic air quality adjustments
• You want quiet operation with pink noise

Skip if

• You require multiple manual fan speed settings
• You have a small room under 800 sq ft
• You need a compact unit under 10 inches wide

Verdict: Alen 45i HEPA 1900 Sq Ft suits large spaces needing automatic purification. It delivers high coverage and quiet performance for bedrooms or living areas.

4 Best budget

Alen 25i Ultimate HEPA Replacement Filter

Best for: Alen 25i owners needing H13 HEPA replacement

Room Coverage

400 sq ft

Filter Type

Medical-grade H13 True HEPA

Target Pollutant

Odor, Smoke, Pet Dander, Allergies, Dust, Mold

Dimensions

2.2 × 9.6 × 12.1 inches

Weight

1.3 pounds

View on Amazon: Alen 25i Ultimate HEPA Replacement Filter Affiliate link

This is a replacement HEPA filter for the Alen BreatheSmart 25i air purifier. It features a medical-grade H13 True HEPA layer that captures 99.9% of particles larger than 0.1 micron. The filter measures 9.6 by 12.1 inches and weighs 1.3 pounds. You can expect up to 12 months of use before replacement. It is designed to clean 400 square feet of air every 30 minutes. This filter suits you if you own the compatible Alen unit and need high-efficiency particulate removal.

Pros

• Medical-grade H13 True HEPA filtration
• Captures 99.9% of particles larger than 0.1 micron
• Lasts up to 12 months
• Covers 400 square feet per cycle

Cons

• Smaller coverage area than other Alen models on this list
• Requires specific Alen BreatheSmart 25i purifier unit
• Filter dimensions are fixed for one device type

Good fit if

• You own an Alen BreatheSmart 25i air purifier
• You need replacement filters for a 400 sq ft room
• You prioritize H13 HEPA particle capture

Skip if

• You do not own an Alen BreatheSmart 25i
• You need a filter for a larger room
• You are looking for a complete air purifier unit

Verdict: Alen 25i Ultimate HEPA Replacement Filter provides essential H13 filtration for compatible units. It fits owners of the 25i who need reliable, long-lasting air cleaning for smaller spaces.

5 Best premium

Alen BreatheSmart 75i Air Purifier

Best for: large rooms up to 2,800 square feet

Room Coverage

Up to 2,800 sq ft

Filter Type

True HEPA

Air Quality Sensor

SmartSensor

Smart Connectivity

App

Target Pollutant

Pet Dander, Allergies, Dust

Control Method

App Control

View on Amazon: Alen BreatheSmart 75i Air Purifier Affiliate link

The Alen 75i covers up to 2,800 square feet, making it the largest option in this lineup. It uses a HEPA filter to capture 99.9% of particles as small as 0.1 micron. The unit includes a SmartSensor that adjusts fan speed based on air quality. It weighs 27 pounds and measures 27 inches tall. This model suits large living spaces or open floor plans where high-volume air cleaning is necessary.

Pros

• Covers up to 2,800 square feet
• HEPA filter captures 99.9% of 0.1 micron particles
• SmartSensor adjusts fan speed automatically
• Proven to enhance sleep with pink noise

Cons

• Heavier at 27 pounds than smaller models
• Larger footprint requires more floor space
• Essential filter lacks specialized odor or allergen treatments

Good fit if

• You need to clean air in a large room up to 2,800 sq ft
• You want automatic fan speed adjustment via SmartSensor
• You prefer a unit that emits pink noise for sleep

Skip if

• You only need to purify a small bedroom under 800 sq ft
• You require a compact unit that fits easily in tight spaces
• You need specialized filters for heavy pet dander or smoke

Verdict: Alen 75i HEPA Air Purifier fits large open areas where maximum coverage matters more than compact size. You should choose it if you need to treat 2,800 square feet with reliable HEPA filtration.

6 Also great

Alen Flex Pure Air Purifier

Best for: Small rooms needing basic particle filtration

Room Coverage

Up to 1,400 sq ft

Filter Type

H13 True HEPA

Smart Connectivity

App

Target Pollutant

Pet Dander, Allergies, Dust

Control Method

App Control

Dimensions

8.5 × 15 × 25 inches

View on Amazon: Alen Flex Pure Air Purifier Affiliate link

The Alen Flex Pure is a compact air purifier designed for spaces up to 1,400 square feet. It uses an H13 HEPA filter to capture 99.9% of particles as small as 0.1 micron. Weighing 15 pounds, it measures 15 by 8.5 by 25 inches. This unit circulates air efficiently in smaller rooms like home offices or guest bedrooms. It is built for continuous operation with energy-efficient performance.

Pros

• H13 HEPA filter captures 99.9% of particles down to 0.1 micron
• Covers up to 1,400 square feet per hour
• Compact dimensions of 15 by 8.5 by 25 inches
• Lightweight build at 15 pounds for easy placement

Cons

• Includes only the Pure filter, lacking options for pet odors or allergens
• No smart home connectivity or app control listed in specifications
• Filter subscription required for lifetime warranty assurance

Good fit if

• You need a quiet purifier for a home office or guest bedroom
• You prioritize basic particle filtration over smart features

Skip if

• You require smart app control or voice assistant integration
• You need specific filtration for pet dander or smoke

Verdict: Alen Flex Pure Air Purifier is a solid choice for small rooms where basic particle filtration is the priority. It fits buyers who want a lightweight, no-frills unit for daily use.

Specifications side by side

Alen Air Purifiers Ranked by Specs

Alen offers six models, all using HEPA filters. The lineup ranges from the compact BreatheSmart 25i to the large 75i. You can choose based on room size. Small spaces suit the 25i or Flex Pure. Larger areas need the 45i or 75i for wider coverage. Some units prioritize quiet operation, while others focus on smart sensors.

The BreatheSmart Large Room model leads for its H13 filtration and automation. The 45i Ultimate suits big rooms needing quiet auto purification. The 25i Ultimate filter is for owners needing replacements. You select the model that matches your square footage and desired features. All units deliver reliable particle removal.

Where Alen Fits Your Home

Alen covers a wide size range. The smallest unit is the 25i, weighing just 8 pounds. The largest is the 75i, weighing 27 pounds. All listed models use HEPA filters. You can choose between white or essential color options. The shapes vary from the slim 45i to the wider 75i. The 25i is ideal for small rooms. The 75i suits large open areas. Note that none of these models include carbon filters for odor removal. You should also know that no smart home integration features are listed for any of these units. This range focuses on basic filtration and size variety.

How to Choose the Right Alen Air Purifier

1. Match Filter Grade to Needs

   All Alen units in this list use HEPA filters, but the grade varies. The BreatheSmart 35i Essential delivers H13 filtration, which captures 99.97% of particles as small as 0.3 microns. This level is ideal for allergy sufferers who need robust particle removal. Other models provide standard HEPA performance. Check the specific filter type in the product details. If you have severe allergies, prioritize the H13 option. For general dust control, standard HEPA may suffice. Always verify the filter grade before purchasing to ensure it meets your health requirements.

2. Select Size by Room Area

   Room coverage determines the correct model. The 75i handles up to 2,800 square feet, making it suitable for large open living areas. The 45i covers 1,900 square feet, fitting big bedrooms or open-concept spaces. Smaller rooms under 800 square feet work best with the 25i or Flex Pure. Match your square footage to the unit’s rated capacity. Oversizing wastes energy. Undersizing leaves air untreated. Check the coverage rating for each model. Choose the smallest unit that covers your space to save money and reduce noise.

3. Consider Physical Dimensions

   Check the width, height, and length to ensure the unit fits your space. The 25i is compact at 11 inches wide and 16.8 inches tall. The 75i is much larger at 18.5 inches wide and 27 inches tall. Place the purifier in a corner or against a wall. Ensure there is clearance for airflow. The Flex Pure is 15 inches wide, offering a middle ground. Measure your intended location before buying. The BreatheSmart 35i Essential measures 13 inches wide. Verify dimensions to avoid fitting issues in tight spaces or crowded rooms.

4. Evaluate Weight for Placement

   Weight affects portability and stability. The 25i weighs only 8 pounds, making it easy to move between rooms. The 75i weighs 27 pounds, requiring a permanent spot. The 45i weighs 14 pounds, balancing stability and mobility. Heavier units are less likely to tip over. Lighter units are convenient for temporary use. Consider where you will place the device. If you move it often, choose a lighter model like the 25i. For stationary use, the heavier 75i provides a solid base. Check the weight spec to plan your setup.

5. Choose Based on Automation

   Some models offer smart sensors and automatic purification. The BreatheSmart 35i Essential includes smart automation for continuous air cleaning. The 45i also provides quiet auto purification. These features adjust fan speed based on air quality. If you prefer set-it-and-forget-it operation, choose a model with sensors. If you want manual control, other options may suit you better. Check the features list for sensor capabilities. Automatic mode saves energy by running only when needed. Decide if you want automated monitoring or manual adjustments.

Frequently asked questions

See also

• alen 35i hepa air purifier vs flex hepa air purifier
• alen breathesmart large room air purifier vs breathesmart hepa air
• best alen air purifiers
• best humidifiers with air purifier