This is very quiet for the price range, with useful air volume at a noise level suitable for sleep. Some mention noise on super (4th) speed, but this is intended as a burst mode.

Four Panasonic F-P15HU2 reviews at Amazon.com average 4.75 of 5 stars.

Consumerguide.com has it rated best buy.

The HEPA filter removes 99.97 percent of airborne particles 0.3 microns or larger, with some efficiency loss on super (high) speed.

Panasonic F-P15HU2 does not include a separate pre-filter to protect the HEPA. Instead, a pre-filter layer is attached to the HEPA filter for easy cleaning.

The HEPA media is vacuum-able, extending the service life for up to three years.

Next is a deodorizing filter with activated charcoal, with a service life of up to one year.

A filter-change indicator reminds users when easily replaced filters need attention. Based on the maker's filter life projections, replacement costs would run about $37 annually.

I'd expect more frequent changes and higher costs.

Automated air purifiers are the future, and Panasonic F-P15HU2 is a genuinely automatic unit.

A particulate air quality monitor, the "Infrared Micro Dust Sensor" regulates the fan speed as needed, saving human effort and time. Noise and energy costs are kept low.

The sensor operates continuously, monitoring the level of airborne particles and communicating by illuminating a sequence of red LED lights on the monitor.

More red LED lights illuminated mean dirtier air, and a faster fan, until air is cleaned.

Units without sensors will soon be obsolete, they are noisy when air has been cleaned and quiet (turned off) when it needs cleaning.

This feedback feature allows users to see the lights change from green to red when they stir up dust.

Of course, this is not a laser particle counter and it detects larger dust fragments rather than pollen, mold spores or cat dander. Allergy sufferers may need to manually adjust the Panasonic F-P15HU2.

Timer mode programs the unit to shut off at a specified time, and interval mode cycles it on and off for energy savings.

Energy use is a not-thrifty 101 watts on super, 75w on 3rd, 57w on 2nd, and 43w on low. With automatic controls, this is less of an issue.

Cord length is an adequate 8.2 feet, and the compact design fits anywhere.

I have seen the Panasonic F-P15HU2 sitting on windowsills and bookshelves.

Measuring 15-5/8 by 21-1/4 by 6 inches and weighing around 14 pounds, this is a portable air cleaner.

Owner gripes center around expensive replacement filters which can be hard to find.

The Panasonic F-P15HU2 is made by an Asian electronics giant focused on the future. A limited one-year warranty is what you'd expect in this price range.

This unit has lots of marketing exposure in vacuum and consumer electronics outlets, and therefore prices vary a lot. Vendor quality and reputation are important, make sure the inventory is "brand new", unopened.

Each of ten factors gets up to 10 points, 100 is perfect and very unlikely.

1. First do no harm; minimal out gassing, no ozone.

Score: 9 of 10.

2. Serious gas and odor removal is a requirement if health benefits are expected: Units with real carbon VOC capability rank higher.

Score: 3 of 10, no real carbon.

3. Quality construction; case, gaskets, seals, and precision fitting eliminate bypassing and assure high efficiency at filtering sub-micron particles.

Score: 6 of 10, filter tray arrangement may lower efficiency.

4. The design maximizes the lifespan of each filter stage by allowing independent filter replacement. Ideally this is combined with electronic filter monitoring.

Score: 9 of 10

5. Unit has long filter life, low maintenance requirements, and reasonable operating costs.

Score: 8 of 10

6. Purifier produces low noise levels and meaningful air flow rates relative to noise.

Score: 8 of 10

7. Manufacturer has a track record, with many units in the field and a reputation for supporting what they sell. Warranty period and average service life are long.

Score: 9 of 10

8. Purifier is a value in terms of price/performance ratio. Every price range should be included, “models above $1,200 are best”, while true, is not useful to most consumers. The list is generally in order of descending price.

Score: 10 of 10, CADR per $ is almost 2, good value

9. No dirt; unit and manufacturer should be devoid of class-action suits, high returns, recalls, consumer complaints, and legitimate negative consumer reviews.

Score: 8 of 10

10. Unit is stylish, portable, comfortable, and convenientfor consumer use.

Score: 10 of 10, clever electronic interface.