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Home > General > Alen BreatheSmart 45i Air Purifier Review 2024: Our Expert’s Opinion

Alen BreatheSmart 45i Air Purifier Review 2024: Our Expert’s Opinion

PK - Alen Air Purifier SAPR

Our Final Verdict

We give the Alen BreatheSmart 45i Air Purifier a rating of 4.75 out of 5 stars.

Quality: 5/5
Filtration: 5/5
Quietness: 4.5/5
Value: 4.5/5
Phone App: 5/5

When you first bring home a pet, you may not anticipate how much they’ll change the air quality in your home. However, even low-shedding cats and dogs often affect air quality, as they can still spread pet dander, track in allergens after returning from walks, or increase dust levels from cat litter.

Using an air purifier can help immensely with keeping your home’s air quality safe and reducing pet odors. However, purchasing and maintaining air purifiers can be a financial investment, so it’s important to research thoroughly before purchasing one. In my search for suitable air filters for pet owners, I’ve come to find that Alen is a brand that’s worth checking out. Alen is a household name in the world of air purification systems, and it’s been producing innovative, high-quality air purifiers for nearly 20 years.

As someone who lives with two cats and a dog, I had to test out the Alen BreatheSmart 45i for myself. This model is known to be the perfect size for studio apartments or main bedrooms. It can pick up pet hair and dander, and it has a filter set that can help reduce pet odors. It’s a viable option for multi-pet homes due to its powerful performance and low noise level. So, it may be a more expensive pet supply purchase, but it’s definitely worth the investment. Here’s everything you need to know about the Alen BreatheSmart 45i and how it could be the best air purifier for your home.



About Alen

Alen BreatheSmart 45i True HEPA Air Purifier - dog sitting beside the box

Alen is a privately held company that was founded in 2005 by Warberg Lee. It produces industry-leading HEPA air purification systems for all kinds of settings, including businesses, schools, and homes.

Who Makes Alen BreatheSmart 45i and Where is it Produced?

Alen is based in Austin, Texas. It manufactures several types of air purifiers that are designed for home use. Each air purifier can cover different amounts of square footage. Some also come with multiple filter customizations, while others have simpler designs that are specialized for one specific use.

Which Types of Pets is Alen BreatheSmart 45i Best Suited For?

The Alen BreatheSmart 45i is suitable for many types of pet owners. It can pick up pet hair and dander, so it’s a good option for those who live with moderate and high-shedding cats or dogs. It can also help reduce litter box odors and is relatively quiet, which makes it a good air purifier to place near litter boxes.

The Alen BreatheSmart 45i covers up to 800 square feet, and it’s designed for studio apartments or bedrooms. If you’re looking for an air purifier that can work in larger living spaces, you may want to look into other air purifiers in Alen’s product line that can take on more square footage, such as the Alen BreatheSmart 75i.


BreatheSmart 45i Air Purifier Overview

Alen BreatheSmart 45i True HEPA Air Purifier - top view of the product in the box

Here is an overview of what you can expect from the Alen BreatheSmart 45i when it first arrives in your home.


The current retail price for the Alen BreatheSmart 45i is between $429 to $498. The type of air filter you choose affects the prices, and you’ll also pay extra if you choose a designer panel. There are currently five different designer panels for this model.

The price range of the replacement filters is $69 to $119. The price depends on the type of filter you purchase. You can also sign up for a filter subscription, which offers a 10% discount on filter replacement purchases and free shipping.

What to Expect

Alen provides free ground shipping on all products delivered within the Continental US. Additional shipping fees apply to deliveries made to Alaska, Hawaii, and Puerto Rico. You can expect products to be shipped and delivered within 2-5 business days for addresses within the Continental US and 7-10 business days for outside locations.

Alen also has a 60 Days Love It, or Return It guarantee. This allows you to test out the air purifier and receive a full refund if you choose to return it within 60 days. Keep in mind that customers are responsible for paying for return shipping fees.

Alen BreatheSmart 45i True HEPA Air Purifier - assembling the filter


The initial purchase of an Alen BreatheSmart 45i comes with the air purifier, a filter, and a user manual. You can start using the air purifier in minutes. All you have to do is take the cover off and make sure that the filter is inserted correctly. It’s a simple and straightforward process, and it comes with instructions. No other assembly is required, and your Alen BreatheSmart 45i will be ready to use in no time.

Once you’ve set up and turned on the Alen BreatheSmart 45i, it’ll immediately start to circulate air. You’ll be able to notice a difference in the air quality within 48 hours.


Dimensions: 15” W 8.5” D x 25” H
Weight: 15 pounds
Room Coverage: 800 square feet
Fan Settings: 4 speed settings
Clean Air Delivery Rate (CADR): 245
Sound Type: Pink Noise
Noise Level: 23 dB – 49 dB

In Summary

  • H13 medical-grade filters can capture particles as small as 0.1 microns
  • Circulates air every 30 minutes
  • Captures 99.9% of dust, allergens, and air pollutants
  • Energy efficient and designed to run 24/7
  • The strongest fan speed can sound loud at first


Key Features

Alen BreatheSmart 45i True HEPA Air Purifier - quickstart guide

Customizable Filter Sets

The Alen BreatheSmart 45i uses medical-grade true HEPA air filters. These filters are capable of removing 99.9% of allergens, dust, and air pollutants down to 0.1 microns. When you purchase an Alen BreatheSmart 45i, you can choose from four filter options that suit different needs:

  • Pure
  • Fresh
  • Odor
  • VOC/Smoke

The Pure filter is the standard air filter that the Alen BreatheSmart 45i uses. It’s a medical-grade H13 HEPA air filter that captures allergens, dust, germs, and molds. The other three filter customizations use the medical-grade H13 HEPA air filter with added filtration.

The Fresh filter includes carbon, and it works to absorb harmful chemicals and VOCs, cooking odors, and common household odors. The Odor filter has an additional odor neutralizer that absorbs pet, diaper, and other common household odors. Lastly, the VOC/Smoke filter comes with extra carbon that absorbs wildfire smoke, secondhand smoke, and other noxious gases and VOCs.

Convenient Phone App

The Alen BreatheSmart 45i can connect to WiFi and is compatible with the Alen app, which is available in both the Apple App Store and Google Play Store. Once you pair your mobile device with the Alen BreatheSmart 45i, you can monitor and track your air quality and control air purifier settings through your mobile device. The app can also send notifications that alert you when there are changes in your air quality or when it’s time to replace your air filter.

Quiet and Non-Disruptive

The Alen BreatheSmart 45i was specifically designed to be quiet and non-disruptive. Its quietest fan speed has a noise level of 23 dB, and its most powerful fan speed’s noise level is 49 dB. Alen intentionally chose to have its air purifiers emit pink noise, which uses deep sounds and lower sound waves that can help promote better sleep. An independent study conducted by SleepScore Labs found that participants using Alen air purifiers fell asleep faster and woke up feeling more well-rested.


Is the Alen BreatheSmart 45i a Good Value?

Overall, the Alen BreatheSmart 45i is a great value for pet owners because of all of its useful features. The Odor filter set is specifically designed to reduce common household odors, including pet odors. The quiet and calming pink noise won’t disrupt or startle pets and can even improve sleep quality. The accompanying phone app is extremely useful as it helps you get a better understanding of your room’s air quality, and it can send you important notifications.

You can also experience several savings opportunities after purchasing an air purifier. Alen offers 10% off and free shipping when customers set up filter auto-shipment subscriptions. You can also join Alen’s Loyalty Program, which offers additional savings through a point system.

Alen BreatheSmart 45i True HEPA Air Purifier - detached front panel



Does the Alen BreatheSmart 45i come with a warranty?

The Alen BreatheSmart 45i comes with a standard 1-year guarantee. It covers manufacturer defects and workmanship. You can also enroll in Alen’s Forever Guarantee by registering your air purifier and activating an air filter subscription or having proof of purchase of an air filter every 12 months.

How long do the air filters last?

The air filters can last anywhere between 9-12 months. The lifespan of the filter will mostly depend on the room’s air quality. Rooms that tend to have higher levels of air particles or pollutants will run through filters much more quickly.  The air purifier has a filter replacement notification on its control panel to let you know when it’s time to order a new air filter.

Do I have to keep the Alen BreatheSmart 45i running 24/7?

It’s recommended to keep the Alen BreatheSmart 45i on at all times so that it can continue to circulate air and consistently maintain the room’s air quality. This air purifier is designed to be energy efficient and typically generates an energy cost of about $0.12 per day.

The Alen BreatheSmart 45i also has adjustable brightness settings for its control display screen. This will enable you to dim the brightness before you go to bed and have undisrupted sleep.

Alen BreatheSmart 45i True HEPA Air Purifier - front panel


Our Experience With the Alen BreatheSmart 45i

I tested out the Alen BreatheSmart 45i in my multi-pet home. I had a great first impression, as I was able to set everything up within minutes. I simply had to make sure to insert the air filter correctly into its compartment. Then, all I had left to do was plug it into an outlet, and it was ready to go. The user manual also had very helpful instructions that helped me connect the Alen BreatheSmart 45i to my WiFi and pair it with my phone.

I was really impressed by the Alen phone app. It provided interesting and thorough insight into my room’s air quality. It was fun to watch the air quality change as the air purifier ran, and the color-coded air quality system was very logical and easy to follow.

I was anticipating loud noises from the fan, but the noise levels were pretty quiet for the most part. The loudest fan setting was noticeable and took me by surprise when I first heard it. However, it didn’t end up being an issue. The pink noise eventually just faded into the rest of the house’s background noise as we got used to it. The air purifier also wasn’t always running on the highest fan speed, so it wasn’t distracting or disruptive, and it didn’t scare any pets.

Another thing I appreciated about the Alen BreatheSmart 45i was its intentional design for better sleep. The control panel had adjustable brightness, and I could quickly dim it before bed. The quiet hum also helped to drown out other background noise, which provided a more peaceful sleeping environment for both my pets and myself.

I had an overall positive experience with the Alen BreatheSmart 45i. It was nice to have peace of mind in knowing that everyone in my house was breathing clean air with significantly reduced pet odors. I was most pleasantly surprised by how useful the phone app was. I liked how it enabled me to compare the indoor air quality with the outdoor air quality and watch the air purifier make adjustments to the air quality in real-time.

Alen BreatheSmart 45i True HEPA Air Purifier - black cat sitting on top of the product




The Alen BreatheSmart 45i is an excellent air purifier for any pet owner. It uses high-quality, medical-grade HEPA air filters to trap particles as small as 0.1 microns and absorb pet odors. It can also completely circulate air within 30 minutes and will automatically adjust its fan speed as it uses laser-sensor technology to monitor your room’s air quality. This air purifier blends in seamlessly with your home, and you may not even notice that it’s running. However, it’s constantly working hard in the background, and you’ll feel such a noticeable difference in the air quality that it’ll make you wonder how you’ve lived for so long without one.

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