Details come from the older review, the maker’s claims and the Amazon listing, checked on October 15, 2026. The older review used coverage numbers that do not match its CADR, so the corrected math is shown. Noise and filter-life figures come from the older review and were not retested.
The SilverOnyx is a light, low-cost purifier for a bedroom or a desk. Here is what it does, how big a room it really cleans and what the filters cost.
Table of Contents
What You Get
Price on Amazon: $78.92 | 4.6 stars from 4,124 ratings (checked October 15, 2026)
Design and Size
The SilverOnyx is a small, round purifier, about 13 inches tall, and the older review said it weighs only 4 pounds. That makes it easy to carry from a bedroom to an office. The older review called it a heavy-duty machine for its size, with five filter stages inside. It is meant for a bedroom, a dorm or a small home office.
Looking ahead, small five-filter purifiers like the SilverOnyx will keep selling on price. The SilverOnyx now costs $78.92 with over 4,100 ratings. The catch is that more filter stages mean more parts to replace, and the older review said the HEPA filter needs a change at least twice a year.
Filters and Features
- Filters. Five stages: a pre-filter for hair and pet dander, an H13 True HEPA filter, a carbon layer for odors and two more layers, per the older review.
- HEPA claim. The older review said 99.7 percent. A True HEPA filter is rated at 99.97 percent at 0.3 microns, so check the label on the box.
- Noise. About 25 dB on low and 56 dB on high, per the older review.
- Upkeep. Some filters can be rinsed. The HEPA filter needs replacing at least twice a year.
The risk to watch is the coverage claim. The older review said the SilverOnyx cleans 500 square feet twice an hour, or 200 square feet five times an hour, with a CADR of 83 CFM. The math does not match. At 83 CFM, a 200 square foot room gets about three air changes an hour, and a 500 square foot room about one. Expect more small units sold on a big room number. Use about 125 square feet for five changes an hour, and about 300 for two.
CADR and Real Room Size
The older review gave a CADR of 83 CFM, below many rivals. In a 200 square foot room with an 8 foot ceiling, that is 1,600 cubic feet, so one air change takes about 19 minutes, or about three an hour. In a 500 square foot room, it holds 4,000 cubic feet, so one air change takes about 48 minutes. Five air changes an hour fits only about 125 square feet. For a bedroom, a desk or a small office, that is enough. See what CADR means.
Filter Cost
Because the SilverOnyx has five stages and the HEPA filter needs a change twice a year, the filter bill adds up. Check the price of a replacement set before you buy, and read the air purifier filter replacement cost guide. For other low-cost choices, see air purifiers for a dorm room.
SilverOnyx vs Other Small Purifiers
The older review named the Alen T500, the Levoit Core 300, the Oransi Finn and the Pure Enrichment 3-in-1 as similar. See our Levoit Core 300 review and the Oransi Finn review. The Levoit Core 300-P has a higher CADR for a modest price gap.
Prices and Alternatives on Amazon
Prices and ratings were checked on Amazon on October 15, 2026.
Price on Amazon: $78.92 | 4.6 stars from 4,124 ratings (checked October 15, 2026)
The SilverOnyx is a five-filter small purifier with a pre-filter and an H13 HEPA filter, per the older review. It has a 4.6 rating from over 4,100 ratings.
Price on Amazon: $43.98 | 4.6 stars from 45,932 ratings (checked October 15, 2026)
The Levoit Core Mini-P is a small purifier for desks, dorm rooms and bedrooms. It has a 4.6 rating from over 45,000 ratings.
Price on Amazon: $89.99 | 4.7 stars from 109,039 ratings (checked October 15, 2026)
The Levoit Core 300-P is listed with a CADR of 143 for smoke, 153 for dust and 167 for pollen. It has a 4.7 rating from over 109,000 ratings.
Price on Amazon: $169.99 | 4.5 stars from 2,574 ratings (checked October 15, 2026)
The Blueair Blue Pure 311i Max is listed for up to 2,107 square feet with Wi-Fi, auto mode and 23 dB quiet filtration. It has a 4.5 rating from over 2,500 ratings.
Pros and Cons
Pros: low price; light and portable; five filter stages; H13 HEPA filter; quiet on low; some filters can be rinsed.
Cons: CADR of 83 CFM is low; coverage claims do not match the CADR; HEPA claim of 99.7 percent is below True HEPA; filters need replacing twice a year; about 56 dB on high.
FAQ
How big a room does the SilverOnyx clean?
About 125 square feet at five air changes an hour, and about 300 square feet at two. The older review claimed 500 and 200, which the CADR does not support.
How loud is it?
About 25 dB on low and 56 dB on high, per the older review.
How often do the filters change?
The HEPA filter at least twice a year, per the older review. Some other filters can be rinsed.
Is it a true HEPA purifier?
The older review said it uses an H13 HEPA filter. The 99.7 percent figure is below the 99.97 percent True HEPA mark, so check the label.
Final Word
The SilverOnyx is a decent low-cost purifier for a small room. For a bigger space or a stronger track record, the Levoit units are worth a look.
What happens next: expect more cheap units with extra filter stages and a free-looking price, then a steady filter bill. Plan on two sets of filters a year.
Related Guides
Keep going with Levoit Core 300 review, Oransi Finn review, what CADR means, air purifier filter replacement cost guide and air purifiers for a dorm room.
