What size room does the Alen 25i handle?

It is built for small rooms such as bedrooms and offices, roughly a few hundred square feet at most. For open living areas, a larger unit is a better fit.

Does it have an auto mode or air-quality sensor?

No. You pick one of four fan speeds yourself; there is no sensor-driven automatic mode.

How often do I replace the filter?

Alen generally recommends a new HEPA filter about every 6 to 12 months, depending on use and air quality. Replace sooner if the filter looks gray or airflow drops.

Is it loud enough to disturb sleep?

On the low speeds it is quiet enough for most bedrooms. The higher speeds are clearly audible, so run those when the room is empty.

Is $165 a good price?

It is the best new price among the three stores listing it as of November 7, 2026. Check the filter's condition and return terms before buying from a marketplace seller.

Does it work for pet dander and smoke?

A HEPA filter captures pet dander and smoke particles, so it helps in a small room. It does not remove odors as well as a unit with a carbon filter.

Where is the Alen 25i Essential White HEPA Air Purifier cheapest?

At Walmart, for $179.00, as of our latest check.

Where can I buy the Alen 25i Essential White HEPA Air Purifier?

3 stores we checked sell it, including Walmart, Lowe's, eBay.

Alen 25i Essential White HEPA Air Purifier

Best price now

$179.00at WalmartObserved at 10:42 PM

Compared across 2 stores. Prices are checked against each store and labelled with when.

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Our take on the Alen 25i Essential White HEPA Air Purifier

The Alen 25i Essential is a compact HEPA air purifier for small rooms such as bedrooms, offices and nurseries. It has four fan speeds and a simple dial-style control, with no smart app or auto mode. The best new price is $165 at eBay as of November 7, 2026, the only new price among three stores listing it.