Sharp Plasmacluster KC-C150U: Humidifier/Air Purifier Review

Sharp Electronics flagship KC-C150U Humidifying Air Purifier, introduced in the spring of 2008, is a contrast to previous Plasmaclusters.

Sharp's newest Plasmacluster, a combined humidifier/air purifier, stands out from the many modestly performing airwasher-style water based purifier/humidifiers. It has real power, a true-HEPA filter, and plasma-ion oxidizers to emphasize the purifier aspect of the combination.

This "wet" Plasmacluster is more powerful than the previous dry models since the plasma ions require airborne water molecules to work.

The major downside is considerable humidifier maintenance when the humidifier is run. I was skeptical about the combined approach, despite the fact that plasma-ion air purifiers, by breaking airborne water molecules to form oxidizers, tend to dry the air. Users will notice a drying of the nostrils when in the room where a Plasmacluster is working.

Apparently Sharp sees the wet machines as the wave of the future, emphasizing the wet KC-C series to to the detriment of previous dry models.

Note that lower-priced Plasmacluster knock-offs, notably the Korean-built Winix Plasmawaves, have cut into Sharp's market. Adding the extra power of the humidity feature is a way to stay ahead of the competition.

I wonder if Sharp's gamble is paying off.

Based on Google keywords searches, it seems fewer buyers are searching for the new models.

I run the humidifier only when the built-in hygrometer reads below 40%, which here in central Texas is rare. As my regular readers know, I use the plasma-ion feature only when I am out of the room.

If you live in a desert environment, need a bit of extra humidification in the dry winter months, or want the most power from a plasma-ion oxidizer,the KC-C150U could solve two problems at once.

Family Tradition

The original Plasmaclusters swept Japan and eventually 20 million were sold worldwide.

This is my third Sharp air purifier, the first two - 2005 FPN60CX and 2009 FPP40CX perform flawlessly and nearly maintenance free.

So I waited until the usual new Sharp price premium faded, and grabbed a new KC-C150U for long term review. KCC150U, after 90 days running in my bedroom, has won me over.

Unlike early Sharps, KC-C150U is made in China.

But contrary to some reviewers impressions ("looks a bit plasticky"), I think the humidifier functions required a slightly stronger backbone, and find the aluminum-trimmed case and control buttons to have a substantial look and feel.

Hey, this is an imported household appliance, not an aircraft cockpit.

KC-C150U Power

The majority of air cleaners sold today are simply underpowered. Machines with CADRs below 150, often advertised as "powerful," are too weak for ordinary rooms.

KC-C150Us have a 12 Volt DC electric motor, providing 3 fan speeds.

These produce AHAM Clean Air Delivery Rates (CADR) at Dust 230/Smoke 224/Pollen 245.

This is above average air throughput, strong enough for rooms to 275 sq. ft.

Normally I rate room size roughly equal to CADR, but the active oxidizers produced by the humidifying air cleaner give it a bit more muscle.

(AHAM rates, and therefore vendors advertise, the KC-C150U for a 347 sq. ft. room - these guys always hafta puff.)

Plasmacluster Automation

A particle sensor adjusts fan speed, but no longer activates the plasma-ion oxidizers.

Perhaps this is a good thing, since many users were confused about when and whether the older Sharps were emitting hydroxyls.

Now users must select the oxidizers by pushing the ion on/off button

Gone is the old Sharp full-control remote - users now touch the top-panel buttons which are quite intuitive.

Fan speed has its own button for three speeds and automatic setting.

Humidifier functions are controlled separately, and therefore optionally, by the Clean Air & Humidify button.

There is no odor sensor.

As usual with automated Sharps, the new KC-C series are very good communicators - indicator lamps show humidity and low water supply levels, while temperature and humidity sensors automatically adjust humidifier output.

A prominent blue light indicates Plasmacluster ions are being emitted.

There is no stand alone negative ion generator, and hence no green light - the absence of blue illumination shows plasma off or lights suppressed by the lights-out button.

Even with the lights off, I find it convenient to cover the panel's last 2 remaining green LEDs for sleeping.

The dust sensor display, on the front below the plasma-on light, shows air quality by changing the color of what resembles a set of bubbles on the front panel.

Green-yellow-red colors depict measured air pollutants.

Temperature and humidity instruments are also incorporated into the Automated KCC150. A humidity display light shows achieved humidity in percent when the humidifier portion of the purifier is operating.

A low water light reminds users to fill the bottle, with a user selectable audible beep to draw attention.

The filter indicator light illuminates after 720 hours of run time, reminding the user to check the filters, vacuum the back panel, and do humidifier maintenance.

KCC's are "Wet Plasmaclusters"

Plasmacluster ion technology in the KC-C150U, and its smalller brother KC-C100U, is Sharp's 5th generation.

Plasma-ion technology splits airborne water molecules into positively and negatively charged ions, radical oxidizers, which attach to and destroy airborne particles and odors.

When used in low humidity rooms, air drying is noticeable.

Many users of dry Plasmaclusters resorted to placing a cup of purified water, sometimes fortified with hydrogen peroxide to inhibit microbial growth, near the air cleaner.

This water evaporates more quickly when the plasma ions are running.

Combining a humidifier increases the available water vapor, extending the lifetime, efficiency, and radius of the ion shower.

(I am on record to the effect that manufacturer claims of oxidizer action at significant distance from the air cleaner, and especially over time, are exaggerated. And that this is a very good thing, the rapid decay of these radicals is a safety feature not present in older, and very popular, ozone-oxidizer air cleaners - a main reason for my enthusiasm for the plasma-ion group.)

Filters

1) Sharp has cleverly designed KCC150's rear shell as a permanent vaccum-able/washable pre-filter screen to capture visible dust and other large airborne particles.

2) The washable activated carbon filter is quite skimpy, perhaps KC-C150's greatest weakness. I guess the idea is that with plasma-ionizer running chemical/odor control is not as important. I add carbon to all my air cleaners, and will get around to making a substitute for this too-thin chem filter eventually.

3) A true HEPA filter conforms to spec - 99.97 percent of particles at the 0.3 micron benchmark size.

Maintenance costs, as with all Sharps, should be low, since the HEPA filter can last up to 5 years.

I recommend all buyers who are not inclined to tear into an air purifier and build or substitute filters purchase an additional set of filters with all new air cleaners. So many are turning up without replacement media after a couple years.

Because the Sharp filters last so long, few retailers stock them, as compared to department store models - Holmes, Hunter... - which are often designed as loss leaders for expensive and frequent replacement filters.

Again, the secret to filter economy is to keep coarse visible dust out of the HEPA. Good pre-filtering is the answer - I will be installing additional pre-filtering on this KCC150U along with the carbon upgrade.

Humidifier Maintenance

Maintaining the humidifier (per the manual) and keeping it clean takes a bit of extra work.

If these systems are not cleaned properly and left dry when not running, they may also breed and spew microorganisms into the air in convenient water-droplet carrying form

This is a big issue for many water-based appliances. But my KCC goes through a tank of water pretty fast - 9 pints, just over a gallon, lasts up to 10 hours per filling.

I just run it dry and leave it until the next time I want humidifier or wet-ion functions.

KC-C tanks and humidifier filter will build mineral scale depending on hardness of water used.

Where hard water is used, frequent cleaning of the humidifying filter and monthly descaling of tank parts will be required to keep the humidifier working.

Sharp specifies tap water, most likely because the chlorine added will resist microorganism build-up in the humidifier section parts.

KCC150u's rayon-polyester humidifier filter, Sharp part number FZ-C100MFU, is slated for two year replacement intervals.

The humidifier filter has anti-bacterial and anti-mold additives, but I think the keys to long wet filter life are soft water and frequent dry-outs as described above.

Folks who need to run a humidifier constantly probably need to get a stand-alone humidifier to separate the task of descaling.

Emissions

In the Sharp tradition KC-C150U is very quiet, making only 17 decibels in low speed (humidifier off) operation. I run it on Medium speed (two) for sleep.

The humidifier-air purifier can produce a "black wall effect" in very urban (freeway/thoroughfare proximity, smoking, or other indoor burning), as ions flocculate soot and attach to light-colored surfaces near the air purifier's exhaust.

A couple feet of clearance is suggested in the user manual, but only for sooty environments.

I have no indoor burning, and with three Plasmaclusters have never had this problem.

Many people are unnecessarily wary of the black wall. To me it is another example of an air cleaner trying to send a message. If you have this much soot in your breathing space, you need major lifestyle changes - an air purifier cannot make up for this kind of continuous source.

Normal households will have no black wall effect, which originated with stand alone ionizers (no filters) to start with.

Again, this is an oxidizer air cleaner, with safety implications for the immunocompromised or ill. While plasma-ion is a great safety advance over other oxidizing technologies and Sharp proudly touts their no-lawsuit record, I run Plasmacluster ions only when out of the room.

Also, many users of oxidizing air cleaners report poor performance in highly polluted rooms.

This is the single most common issue in all air cleaner purchase disappointments: Users falsely believing the air cleaner can remove continuous sources, like mold in a wet home, smoke of any kind, or chemicals which don't belong indoors.

Users in these circumstances face much higher filter costs and suboptimal performance.

Cases have come to light where paint or other VOC's have been applied, and an oxidizer set up, with disastrous results. Partial oxidation by-products can be generated, and may be difficult to remove is extreme cases.

No air cleaner is a panacea for inadequate source removal/remediation and poor ventilation.

Utility

Sharp claims KC-C150U, Energy-Star rated at a modest 2.42 Dust CADR per Watt, is 35 percent more energy efficient than standard models. This must be based on the higher performance of the dual ionizer and wet plasma, because this is a lower rating than typically seen in Sharps.

www.1greenproduct.com tested a KC-C150U with a Kill A Watt EZ Electricity Meter, with humidifier off.

Max speed consumed 75 watts, Med 14 watts, and Low a measly 5 watts.

1greenproduct asserts that Plasmacluster function had no measurable energy effect, but lights-off mode cut one or two watts.

Sharp warrants the Plasmacluster KC-C150U parts and labor for one year from date of purchase.

Conclusions & Rating

Plasmaclusters have a price decay pattern, and KCC150U prices have fallen enough, from the initial retail at $499.99, for me to be a buyer.

I bought Sharp KC-C150U for $329.99 at Fry's Electronics, one of the few retailers in Texas which still carries a selection of air cleaners. (The other is Sears, which sells rebranded air cleaners at significant markups.)

KC-C150U is a good pick for buyers who want a humidifier and an air purifier.

I also have a competing plasma-ion machine, a Winix 5300 Plasmawave, which sells for less than half the price. I had some issues with a strong insecticide smell from the Winix prefilter, which I replaced with alternate materials. After adding a 3-pound carbon bag, I have a nice Sharp-wannabe for just $166.

I like my KC-C150U, it has power to clean air, elegant/quality appearance, and quiet automation.

Is it worth twice the price of a Korean knockoff? Maybe not.

The extra humidifier maintenance will get a slightly lower rating below as compared to previous Sharps.

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, builder says Plasmaclusters are "safe", Caution is warranted.

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 is weaker than I need, even when 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,

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

Score: 10 of 10

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

Score: 9 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, Sharp is a world leader in quiet air cleaning.

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, millions sold, but warranty is shorter than filter life.

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, 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, some filter availability issues Sharp seems unable to handle.

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

Score: 10 of 10, easy automatic interface.

Air-Purifier-Power Numeric Rating; 90.