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Corsi-Rosenthal Box with Single Filter Air Purifier Review

Tested using Methodology v1.0
Reviewed May 13, 2024 at 01:24 pm
Corsi-Rosenthal Box with Single Filter Picture
5.8
Pets
4.6
Bedroom
6.5
Air Purification

The Corsi-Rosenthal Box with Single Filter is a build-it-yourself air purifier and effectively a simplified version of a standard Corsi-Rosenthal Box. As the name implies, it's effectively just a box fan taped to a single MERV 13 furnace filter. As with the full-size design, filtration performance and feature sets can vary depending on what components you use. However, your build will return broadly similar results using high-quality filters and a relatively potent box fan.

Our Verdict

5.8 Pets

Our single-filter Corsi-Rosenthal Box is middling for pet owners. It has a hard time with the smallest airborne particles, like cat dander, and lacks any odor-absorbing carbon filter layer. It's also very noisy, which isn't great if your pet is particularly sensitive to loud noises.

Pros
  • Reasonably high clean air delivery rate.
Cons
  • Noisy operation.
  • No smart functionality.
  • Poor particle filtration performance.
4.6 Bedroom

Our single-filter Corsi-Rosenthal Box is ill-suited to use in bedrooms. It's loud, noisy, and ugly, though it takes up much less room than the full-size four-filter Corsi-Rosenthal Box. Its particle filtration performance also lags far behind that of its larger stablemate.

Pros
  • Reasonably high clean air delivery rate.
Cons
  • Noisy operation.
  • No smart functionality.
  • Poor particle filtration performance.
6.5 Air Purification

Our single-filter Corsi-Rosenthal Box is okay for general-purpose air purification. It has a reasonably high clean air delivery rate, but compared to its full-sized alternative, it does a much worse job of trapping the smallest of airborne particles. It's also quite noisy, though admittedly less than the four-filter version.

Pros
  • Reasonably high clean air delivery rate.
Cons
  • Noisy operation.
  • Poor particle filtration performance.
  • 5.8 Pets
  • 4.6 Bedroom

Performance Usages

  • 6.5 Air Purification
  1. Updated May 07, 2024: Review published.

Differences Between Sizes And Variants

This is a single-filter iteration of a standard four-filter Corsi-Rosenthal Box, which delivered drastically different overall performance.

Compared To Other Air Purifiers

Compared to the full-size Corsi-Rosenthal Box, this single-filter alternative is a bit of a letdown. It has a much lower clean air delivery rate and does a far worse job when sealing in fine particles. While it is cheaper than many commercially available air purifiers, there are quite a few reasonably-priced options out there that boast not only superior performance but also a wide variety of smart features, like the Winix C545.

Test Results

perceptual testing image
Design
Design
Body
Height 21.9" (55.5 cm)
Width 20.7" (52.6 cm)
Depth 5.3" (13.4 cm)
Weight
7.2 lbs (3.3 kg)
Power Cord Length 72.1" (183.1 cm)
Wheels
No
Design
Display And Control
Filter Change Indicator
No
Air Quality Sensor Auto Mode
No
Remote Control
No
App
No
Display On/Off
No
Timer Function
No
Number Of Fan Speeds
3

The Lasko 20-inch box fan we used for our Corsi-Rosenthal Box has three levels of fan speed adjustment.

Design
Filter Configuration
Filtration Layers
1 Stage
Activated Carbon
None

Our single-filter Corsi-Rosenthal Box's filter system consists of one 3M Filtrete 20x20x1 MPR 1900 Premium Allergen, Bacteria & Virus Smart Air Filter. This filter has an estimated lifespan of three months when used in a home furnace, air conditioning, or HVAC system; their lifespan in an air purifier will fall within a similar ballpark, depending on how often you run it. You can buy a set of four filters here.

Performance
6.5
Performance
Particle Filtration
Air Cleaning Rate
451 m³/Hour
Average Final 0.3 µm Concentration
658 particles/L

Note that the air purification performance largely depends on where and how you place the unit in a room; we tested it with the filter side facing outwards, but its performance was significantly worse if its filter side was left facing a wall from the normal testing distance of 1".

3.5
Performance
Noise
Noise @ Lowest Fan Speed
48.0dBA
Noise @ Highest Fan Speed
60.3dBA