Sharp Plasmacluster FP-P40CX Air Purifier Review

The Plasmaclusters, including FP-P40CX, have been heartily accepted by the market.

Since being introduced in 2001, Sharp Plasmaclusters in all their forms (in air purifiers, air conditioners, luxury auto cabins, and refrigerators...) have now sold over 20 million units in 58 countries around the world.

Designed in Japan, the first Plasmacluster air purifiers built a reputation for strong value, with unparalleled cost/performance ratios.

I liken Sharp Electronics to Toyota Motor - becoming a global giant has hurt quality. Today's Sharps are made-in-China, use slightly less of everything, dulling the sparkling value proposition slightly.

Sharp has incorporated a humidifier into the newest versions of the Plasmacluster air purifiers. These, the KC-C150U, KC-C100U, and KC-C70U, have water tanks to refill. (KC-C70E, KC-C100E, KC-C150E, in the UK).

Most current Sharp buyers are choosing between these newer water-tank (humidifier-purifier) models, and the remaining dry models of the FP-P series.

With FP-P60CX now disappearing, the smaller FP-P40CX is the main dry alternative.

My first Sharp, a 2005 FP-N60CX, performs well, with the original "5 year filters," after over 4 years of continuous operation. Maintenance expense has been exactly zero.

So I recently purchased a Sharp Plasmacluster FPP40CX for long term evaluation.

FP-P40CX has 3 enthusiastic user reviews at amazon.com, averaging 4.7 stars.

One air-purifier-power Power User, an experienced Sharp owner, submitted extensive remarks for this review, they are quoted in italics where featured.

FP-P40: Not For Large Rooms

Association of Home Appliance Manufacturers (AHAM) certified Clean Air Delivery Rates (CADR) are; dust 157, smoke 163, and pollen 156.

FPP40CX is AHAM rated for a 252 square foot room.

I think it is perfect for my 10 by 16 bedroom, 160 square feet.

In general I recommend CADR roughly equal to room size. With the Plasmacluster technology actively cleaning, a bit bigger might work.

FPP40CX's 12-Volt DC fan motor has 3 fan speeds; Silent, Med, and Max.

Power User notes;

"One slightly hidden but useful feature of the P40CX is the ability to run 'Pollen' mode in order to get a high speed which is intermediate between the manually selected medium and maximum speeds (I find 'maximum' too noisy to use while someone is in the room).

This speed only holds for ten minutes beforethe unit starts cycling between medium and 'high', but it's better than nothing.

I don't know why Sharp didn't simply make 'high' a manually selectable setting they way they did on the 4-speed N60CX; I can't imagine that they saved more than a few pennies in parts."

The stepped-down voltage makes the FP-P40cx energy efficient and quiet.

Many air cleaners still use the full 110 volts of normal household current.

Sharps use a squirrel cage fan, as found on less expensive air cleaners.

Power User has noticed a wobble common with the Plasmacluster fan.

"The fan on my unit wobbles considerably, especially at lower speeds. On closer examination, it appears that the motor shaft is true, and that the problem lies in the rubberized bushing that mounts the fan to the motor shaft.

The wobble appears to have no practical impact - my unit is very quiet and seems to be vibration free, so this doesn't seem to be anything worth worrying about."

My FP-P40CX fan also wobbles, a bit more than the FP-N60CX fan which has run perfectly for an estimated 25,000 hours without incident.

FPP40CX Filters

A filter frame supports the carbon bag and HEPA, and has anchor slots for a permanent washable screen prefilter.

Some users think the Sharps filter cassette looks "flimsy," noting the filters are secured primarily by pressure from the front panel.

But in 4 years there has been no fine dust accumulation around the fan (indicates bypassing), I put scotch tape on my Plasmaclusters to seal the filter frame edges to the case.

The washable/vacuum-able pre-filter is a fiberglass screen with tabs to lock into the cassette tray and touch the back of the front panel.

This is a very sturdy part, never needing replacement with normal use.

Behind the screen and held by straps which hook over the screen top edges, is the Sharp carbon bag. The nine chamber washable carbon filter bag adsorbs many common chemicals and household odors.

With about 11 oz. of granular activated carbon in a pleated polypropylene and polyester bag, the FP-P40cx washable odor filter is a middle weight odor/chemical adsorber, claimed to retain over 4000 chemicals.

This is an inexpensive solution to the activated carbon VOC/odor filter problem. Premium class air purifiers have heavier carbon, plus additional adsorbents and oxidizers to deal with chemicals which activated carbon tends to desorb and outgas.

This deficiency, common to mid-priced purifiers like the Sharps and their immediate class competitors, is overcome in IQAirs and other premium brands with potassium permanganate and other additives to target difficult chemicals like aldehydes.

The air-purifier-power.com user community has experience with this issue, see Sharp Plasmacluster Washable Carbon Bag Issues and Refills

So users with high aldehyde levels - mobile homes, leather furniture, fragrance saturation, near freeways... - may need to replace or refill the carbon bag much more frequently than the 3 years predicted by the manufacturer.

Also, ozone generators, fresh paint, moth balls, and many other heavy chemical loads will saturate this carbon in as little as 90 days. The majority of dissatisfied customers who bought a better quality air purifier are those who failed to clean house before installing the air cleaner. Source removal and ventilation are required for success.

Sharps have the true HEPA (99.97%@.3micron) filter last. This filter is actually a bit flimsy, I'd rather have a sturdier edge - there is no cardboard liner. But once inserted in the cassette tray it lasts indefinitely.

Newer Sharps, like FPP40s, have an antimicrobial additive to protect the HEPA from germ growth.

While newer FPP40 literature is not specific, the germicidal agent is most likely Apatite (calcium phosphate).

There has been some controversy about the safety of just about every anti-microbial agent added to air filters.

The apatite used in air purifiers does not contain arsenic.

My FP-N60cx runs by my chemically sensitive (MCS) side with no toxicity after 4-years.

HEPA filter life is a projected five years with normal household particle loads.

Power User:

"I noticed that on both the P40CX and the N60CX there is a small rectangular duct (perhaps a half inch long by an eighth inch wide) in the top left hand corner of the cavity in the main unit into which the filter frame fits.

Oddly,this duct is within the area which is sealed off by the filter frame; in other words, any air which passes through it will completely bypass the filters and move directly to the fan.

Curious, I removed the cover from the unit and was surprised to see that the duct simply opens up to the interior of the frame, with no valve of any kind. Since the frame is not air tight, Sharp appears to have simply built in a small air bypass into the unit.

Possibly this serves to increase airflow past the odor sensor (which is located in a near-by area ofthe frame) but I'm surprised that Sharp would design the unit so that it's possible for some air flow to completely bypass the filters."

This duct is the dust sensor passage, unused on the single sensor FP-P40CX, but needed on FPR45CX, a near twin sold in Canada and elsewhere. The main circuit board in my FPP40CX is printed with the letters "FPR45."

My FP-P40's unused dust sensor passage is sealed in front, but could draw a very small amount of air through the case.

Replacement filter kit FZ-R45HFU, contains both filters and sells for $97.95 to $142.95 USD, close enough to the price of the FP-P40CX to buy a new air purifier instead.

I do not plan to ever purchase filters for FPP40CX. My 4-year old FP-N60CX just had the carbon bag refilled with new carbon ($13) and the HEPA, though discolored, is not restricted. I expect the same results from the new FP-P40CX.

Users in heavily polluted high particulate environments may clog the FPP40CX HEPA sooner. Because of the scarce replacement filter environment which has prevailed in the recession, those with high-dust situations may want to order two sets of filters with the purchase.

Many retailers show the FP-P40CXs' filter set out-of-stock.

The clean filter reminder light comes on after about two months of round the clock operation, suggesting a wash of the filter bag.

When the carbon filter is washed every two months, it is projected to last five years.

Washing is some work; vacuuming, soaking in mild detergent, brushing, and hanging for complete drying.

The bag needs about a day to dry after washing.

Plasma-ion Oxidizer

FP-P40CX and its brothers combine passive air filtration, traditional HEPA and carbon, with active hydroxyl radical based oxidation to permanently remove air contaminants.

Sharp's Plasmacluster ions separate airborne water molecules into positively and negatively charged radicals, which diffuse through the room, surrounding airborne particles

Tiny airborne sub-micron particles and complex toxic organic molecules and micro-biologicals are oxidized.

Hydroxyl ion clusters have a half life as long as 5 seconds, so they can oxidize some distance from the FP-P40CX.

Figuring an estimated exhaust air speed of 2 feet per second, plasma ion clusters could survive up to 10 feet from the air purifier.

The density of oxidizers declines with distance, making the Plasmacluster the safest oxidizing air cleaner. Unlike ozone-based oxidizers, there is no accumulation or residual to be ventilated.

But this is oxidation, a powerful force which can be dangerous to the naive. I do not sleep with the positive ion blue light running.

If there is a condition which makes the blue light stay lit a significant percentage of the time, there is a source in the room that should be eliminated.

Users are cautioned against thinking any room air purifier can detoxify fresh paint or other strong chemicals without high filter costs. Oxidizers can also create partial oxidation by products when the load it too heavy.

The 2009 H1N1 influenza media frenzy has air purifier marketers going wild, each trying to out do competitors' claims of germicidal effectiveness.

Laboratory tests have shown Sharp Plasmaclusters can significantly reduce airborne viruses.

But flu viruses are best combated by wearing face masks, washing hands, and avoiding crowds of carriers. Air purifiers are valuable, but do not offer complete protection as some vendors imply.

Sharp Automation

Manual Mode allows total user control of both fan speed and ion generation.

FP-P40CX is best managed using the comprehensive remote control, with its 23 foot range.

The air purifier may also be operated from the unit's control panel.

But the Sharps' real strength is the automatic functions.

Clean Mode (blue lamp on) is the plasma-ion mode, with oxidizers released.

Ion Control Mode (green lamp on) releases negative ions only. I use this mode whenever I am near the machine, avoiding direct exposure to the positive-ion induced oxidants.

Negative ions are lacking in many areas, especially near freeways/traffic corridors, where particulates from engine exhaust flocculate them.

Auto Mode switches between Clean Mode (blue light and oxidizers on) and Ion Control Mode (green light and negative ions only) and turns up the fan, under control of the odor sensor.

This sensor can "smell" a variety of household odors.

Sharp has dropped the particle sensor, the subject of a post here. This looks like another cost cutting measure, very common in the tough 2009 recession.

See: Sharp FPP series lacks dust sensor for more.

The Clean Sign indicator provides feedback to the user, showing green, orange, and red colors as odors come and go.

When a Plasmacluster is first plugged in, the purifier sample the room air and set a baseline quality level, used as a metric for control.

This can create a small issue when a new Sharp is set up in a less than pristine room. Once the air is improved, and the FPP40 may seem to be shutting down too soon, it may need its baseline reset by unplugging, repowering, and resampling.

A timer shuts off the air cleaner after 1, 4 or 8 hours.

Quick-Clean and Pollen Modes are provided for brief burst cleaning situations.

FPP40CX Emissions

The low fan speed is soundless and medium speed is very quiet. I have slept with Max fan, but it is too loud for easy TV viewing.

Sound specs are 49 / 30 / 17 dB(A) on each of the three speeds.

I have a Radio Shack sound level meter, designed more for measuring acoustics in auditoriums than air cleaner sound. It has a lower threshold of 50 decibels and cannot measure the very quiet FP-P40CX Sharp's sound.

On the 17 decibel Silent setting, the purifier cannot be heard at 6 inches. On Medium, it is extremely quiet.

All Plasmaclusters make a small ticking noise, very slightly different depending which ions are being generated. Some find this click disturbing when trying to fall asleep, which I do not recommend (run blue light before bed, then green light or just filters while asleep).

FPP40cx has a very bright front panel, which can be switched off at night using the remote. A small green fan speed light stays lit, I cover the Medium speed light with a small tab of paper for even less light emission.

Turning off the lights hides the clean sign and oxidizer lamps.

Plasma-ions de-humidify the air, reducing their own effectiveness over time, and can cause a drying of nasal passages. This is why Sharp has gone to the newer humidifier models with water tanks, and why many users place a cup of water on or near the machine.

Sharp claims that Plasmacluster efficiency is doubled with high humidity.

Ozone is not an issue, with emissions near zero (>.01 ppm).

Again for emphasis - plasma-ion oxidizers should not be used where strong chemical sources persist. Painting a room or refinishing furniture and then expecting the Plasmacluster to clean it up is NOT recommended! The result can be partially oxidized chemical contamination.

Fragrant sprayed "air fresheners," especially the plug-in electric models, are one such source.

"Always remove toxic sources before installing any air cleaner," applies doubly to oxidizers.

FP-P40CX Utility

Measuring 16-3/8" W x 22-1/2" H x 7-7/8" D FPP40CX is compact, but not small.

Weighing just 14.8 lbs., it can easily be carried.

The power cord is long enough that Sharp FP-P40CX doesn't have to stand right in front of an outlet.

Plasmacluster 40-series are EPA ENERGY STAR qualified at 3.14 dust CADR/Watt, about average for Energy Star air cleaners.

On low, the 12 Volt DC motor uses around 3 watts of power.

Turn the the negative ion generator on, this jumps to a mere 5 watts!

On the Max speed with the Plasmaclusters running, it's energy use is cited as about 50 watts.

Power User has measured this:

"My P40CX actually uses less energy than stated in the printed specifications.

Checked with a handy-dandy Kill-a-Watt meter (a cheap, fun, andvery useful gadget if you don't already have one), my unit uses a mere 2 watts on low (manual says 3.5 watts), 6 watts on medium (manual says 7.5), and 43 watts on high (manual says 50).

Since I have no way of directly measuring air flow, I don't know whether the machine is actually more efficient than claimed, or just using less power to move less air.

Interestingly, it seems possible to use wattage consumption as a crude proxy for measuring changes in air flow, though the relationship is the opposite of what one would expect.

Running the unit with the filters removed obviously increased air flow substantially; the fan ran much faster and wattage consumption nearly doubled.

Conversely, adding a very thin prefilter apparently decreased airflow a bit, since wattage consumption with the additional prefilter in place decreased roughly ten percent."

Some smokers have complained about increased electric bills because their Plasmacluster air cleaner is running full power almost continuously.

Smoking households will always have much higher air quality costs.

Again, when continuous oxidizer functions are seen, the message is "clean up pollutant sources, your air purifier is not a bulldozer."

At my rural cabin, the clean sign indicates poor air quality only when neighbors are burning something. In Houston, the Plasmacluster is a warning system for poor outdoor air quality. It says "turn up the IQAir, wind is from the east."

Warranty

Sharp is a global leader in microelectronics.

When I first reviewed the Sharp FP-N60CX, I said here was a company with staying power. That was almost five years ago.

In those five years, the air cleaner market has undergone a revolution; former market leaders have been trashed by ozone emissions from electrostatic grids, many other builders have abandoned the overbuilt business, and survivors, including Sharp, have cut models.

Quality support has become harder to find, as warranty claim costs, a big influence on the bottom line, are cut everywhere.

The Plasmacluster's warranty is short, 1 year parts and labor from date of purchase.

Sharp US offices and customer service are in Romeoville, Illinois.

Conclusions

Despite some dilution of the value proposition, Sharp Plasmacluster is still the benchmark for the Asian invasion air cleaners.

New competition from Mitsubishi (sold as RabbitAir), Winix Plasmawave (basically a lower priced Korean Plasmacluster knockoff), and the entry of Korea's Coway (High-end RabbitAirs and low end Idylis air purifiers), has crowded the mid-price market.

Some buyers in this price class see the Sharp FP-P40CX as "more expensive" than Hunters, Bionaires, Holmes, Therapures, and other big-box department store models.

Actually, long term cost of ownership favors the Plasmacluster, with its durability, long filter life, active technology, and low energy costs.

Sharp Plasmaclusters are widely available on the web - Google products shows 33 sites offering FPP40s from $227.49. I paid $259.95, before tax, at Fry's Electronics.

FPP40CXes have sold on eBAy for $199.99 plus $30 shipping.

The Sharps historically have had price fluctuations - sales events that sell out quickly and go to back-order while higher priced vendors still have inventory.

You will see FP-P40cx listed as high as $379.00.

FP-P40CX Review Rating

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: 8 of 10, FP-P40CX ozone levels are safe, but Plasmacluster's oxidizing power is dangerous to the uninformed, and safe when used properly.

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

Score: 8 of 10, washable carbon filter combined with ion-oxidation

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

Score: 8 of 10, filter basket system has lower efficiency than premium class air purifiers.

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

Score: 8 of 10, FPP40CX filter kits have both HEPA and carbon together, but carbon bag can be easily refilled.

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

Score:10 of 10, cheaper to own than lower priced units.

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

Score: 10 of 10, excellent sound to airflow ratio, very quiet.

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: 8 of 10, warranty is short and stateside parts availability outside the company's contractor network is limited, but Sharp Plasmacluster's record sales, long filter life, and durability speak volumes to the informed.

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.

Score: 9 of 10, Good value in lower mid price air cleaner class, but not an allergy shop premium brand. Sharps exhibit price fluctuations, be sure not to pay full suggested retail.

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

Score: 9 of 10, company likes to brag about how seldom they are defendants in lawsuits.

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

Score: 10 of 10, handy remote, great automated interface.

Air-Purifier-Power Numeric Rating; 88, Sharp FP-P40CX is a very good plasma-ion oxidizer in the under-$300 class.