Quiet Air Cleaners

fresh · Post by **fresh** » Sat Jul 07, 2007 8:27 am

A week ago I decided to do something about unbearable air conditions that have overtaken my workspace (computer filled bedroom). Since it's an old building dust is just pouring everywhere.

I was considering HEPA filters with ionizators, moisturaisers with ionizators and Biozone photoplasma products. Last mentioned are very quiet (Biozone Purehome 500) and said to be efficient, but price is up to 3 times higher. One of the problems I was facing with selection is the lack of data. Every last one of the products sold in stores is said to be best and there are almost none laboratory studies on internet to confirm such fragile claims. Therefore I decided to do more exploration of that area

Do any of you have good or bad experiences/opinions about certain air cleaners, which are worth buying considering efficiency/noise/(price) ratio.

I'm looking forward to your replies.

subsonik · Post by **subsonik** » Wed Jul 25, 2007 2:02 pm

Sorry for the topic kick, but I thought it was worth it sharing my experiences.

I have the same problem, ridiculous amounts of dust all over the place, despite regular vacuuming (2-3 times weekly). I've done quite a lot of research on air cleaners.

Finally, I bought a fairly expensive plasma streamer unit from Daikin (MC-707). That's when I discovered that this technology tends to emit ozone... after a few days of heavy headaches

Unbelievable that a 400 EUR ($550) air purifier actually poisons the air.

Fortunately, I could remove the plasma unit and get rid of the ozone problem. The unit has 5 speed settings, the lowest is near to inaudible and moves 60mÂ³/h. Highest setting moves about 400mÂ³/h, quite impressive. It has a huge centrifugal fan spinning at very low RPM.

The unit is running at a 240mÂ³/h (140 CFM) setting for about 18 hours a day, and at a 120mÂ³/h setting for the remaining 6 hours. My dust problem in the smallish 15mÂ² room didn't go away! I think it's maybe one third of what it was before... The recommended room size for this air cleaner is 60mÂ², 4 times the actual size.

Hence, you will need a REALLY powerful air cleaner to get rid of the dust. Powerful air cleaners are loud and/or big, without exception. Regular vacuuming might be more practical.

If you really want to go with an air cleaner, check the CADR (clean air delivery rate, in CFM). Buy a BIG unit (big filter, less airflow restriction - big fan, less noise). Forget about the ionization units, they're all crap without exception.

fjf · Post by **fjf** » Wed Jul 25, 2007 2:24 pm

Electrostatic air cleaners work very well, and the metallic grid that traps the charged dust can be removed and washed with water. Easy, economical and clean. I purchased the European version of this one: http://www.friedrich.com/aircleaner/
Works very well, although I had to undervolt the fan to use it in my bedroom.

Bluefront · Post by **Bluefront** » Wed Jul 25, 2007 4:02 pm

Bottom of the thread today.......This may not solve all your problems by itself, but it's very quiet on low speed. The HEPA filter can be cleaned and reused. Perhaps several of these units might run quieter than one big machine.

fresh · Post by **fresh** » Wed Jul 25, 2007 11:46 pm

Thank you all for your replies. I just made a quick go through, and some ideas seem very convinient (I will have more time in the evening). Sad to say I already bought a HEPA filter with ionizator. But it's like subsonik said:'Ionizators all suck without exception.' It made some diffrence. Oh yes. It made me aggitated, nervous and even aggresive when in bad mood. So I haven't switch it on for quite a while.

The idea of cleaning HEPA filter seem very useful, since it is said to be replaced once a year, and it costs around 40â‚¬. My is VERY loud (from vicks). There is one thing more that I have to ask bout HEPAs. I got the feeling that it sucks the air dry. Not the filter (I didn't notice that in first week of use), but the dust collected in there. Is it just my imagination, or is it true. If so, humidifier is also needed.

When I get the chance I will explore some of the suggestions you wrote, since I will without doubt get rid of my current "solution".

fresh · Post by **fresh** » Thu Jul 26, 2007 12:58 am

Bluefront Check this out. Is it possible that it's the same silent product? It' said to be made here in Slovenia by Gorenje. It looks exactly the same, is there any way of checking out, whether it's the same product?

Bluefront · Post by **Bluefront** » Thu Jul 26, 2007 3:31 am

Man that does look exactly the same......unless it is a fake/copy I'd say it is the same thing, maybe made to the same specs by a different supplier.

I don't think these HEPA filters remove any moisture from the air.....if they did, there would have to be a liquid catch tank/tray on the bottom. There is none. It's just a filter, like any other air filter....only more efficient.

fjf · Post by **fjf** » Thu Jul 26, 2007 5:18 am

Hepa filters trap dust, but as the filter gets more and more filled with it, the air path gets blocked. After a few months of use (or weeks, depends on the dirt they accumulate) they have to be replaced for new ones. They work well with good filters, but you have to keep buying new ones.

The electrostatic filters charge dust particles and trap them in charged metal plates; you just wash them and keep using them for years. Much more effective. The trapping is not limited by the size of any filter, but for the charge of the particles.

Ionizers charge the dust particles but they do not trap them; they leave the ionizer and then they stick to the walls and everything in the room. Very dirty job. Not recommended.

klankymen · Post by **klankymen** » Thu Jul 26, 2007 5:39 am

Bluefront wrote:Bottom of the thread today.......This may not solve all your problems by itself, but it's very quiet on low speed. The HEPA filter can be cleaned and reused. Perhaps several of these units might run quieter than one big machine.

just so you know, you can link to specific posts (I just found the button myself a few weeks ago), by clicking on the little orange or white page in the top left corner of your post (

/

).
So you would be linking to this url.

fresh · Post by **fresh** » Thu Jul 26, 2007 10:17 pm

I know electrostatic filters seem better, but I couldn't find any to buy in Slovenia and the one you showed costs 500 bucks, which is 3 times more than I am willing to pay for it. I am thinking of savaging Vicks I have, take out ionizators and lousy loud fan, and put 2 nexuses in. I already have the ac to dc adapter that switches between 3,5V and 12V.

Bluefront · Post by **Bluefront** » Fri Jul 27, 2007 3:45 am

Damn...I wouldn't pay $500 for that thing. I'd make one first. Most of these thin air cleaners use a squirrel-cage blower rather than a standard axial fan. But that doesn't mean you couldn't construct a good room air cleaner using a bunch of Yate Loons, for instance.

I'd try to design the fan around a commonly available/good filter. A high quality furnace filter is a good option. They come in standard sizes, and should be available in a number of brands, for a long time. There is a 12"x12x1" size in the USA, that would make a nice-sized room air cleaner.

Actually......I'd probably use one of the new 220mm fans that can be had these days. They're relatively cheap, and quiet.

I designed a custom air filter assy for my parrot cages....I use a 20x20" furnace filter(easy to find/replace). In this design I blow air through the filter, rather than suck through the filter. It was easier to construct....works ok.

subsonik · Post by **subsonik** » Fri Jul 27, 2007 1:20 pm

Electrostatic units indeed do a very good job on cleaning the air, plus the electrostatic filter is not very restrictive to airflow - meaning this type of unit is relatively quiet. However, most of the electrostatic units tend to emit some ozone. I suppose its health risk is well known.

I've also played with the idea of constructing a DIY air cleaner. But there are 2 big issues: first, where to find cheap but good filters? And second, where to find a decent fan, at a moderate price?

The reason most of these air cleaners use a squirrel cage fan, is that this type of fan builds up a lot more pressure than axial fans. Without the pressure, you can't push the air through the filter. Sadly enough, decent squirrel cage fans cost a fortune... An 8" model costs $200 easily (all-metal industrial type). The cheap plastic types as used in cheap A/C's (and air cleaners, off course) are very hard to find.

If you want to construct something with axial fans, you will need LOTS of filter area to reduce the backpressure. If "woman acceptance factor" of your DIY cleaner is not an issue, you could build a filter panel the size of a door, with a bunch of fans behind it

MoJo · Post by **MoJo** » Mon Jul 30, 2007 7:30 am

I have a Sharp FU-40SE. It's a nice compact unit and does and excellent job. I live by a main road and have really noticed the difference it makes. I suffer from dust allergies, and after a day there is a fine layer of dust on everything in here.

Best of all, it's silent at the lowest speed. It has both an ioniser (which is always on and always silent) and a HEPA filter with a fan. It also has an automatic mode, where it stays in silent mode most of the time and ramps up if the air is dusty. It's quite sensitive - if I open my wardrobe it usually comes on for a minute or two. I sleep with it in the room without problems. The central heating is a lot louder.

subsonik · Post by **subsonik** » Thu Aug 02, 2007 1:30 pm

MoJo, does your Sharp produce ozone? I've read reports of users concerned about 'sweet odors' emitted by the machine, and 'irritated eyes' in the neighborhood of the exhaust.

Try running it in your closet for an hour, with the plasma function on. If it emits ozone, you'll smell it easily. It smells a little sweet, you'll probably know the smell from electric motors, e.g. power drills.

If I run my Daikin in the closet for an hour, I can't breathe there, and my eyes get irritated.

MoJo · Post by **MoJo** » Thu Aug 02, 2007 3:01 pm

According to the manual it does produce small amounts of ozone. There is certainly a slightly different smell to the air emitted by it (I wouldn't say sweet... clean perhaps, like fresh air out in the country.)

I have not had any problems withe irritation. I have it set to automatic mode where the plasma function only comes on for a few minutes at a time anyway. I do occasonally run it full blast for an hour or so, but again didn't notice anything. I get a lot of irritation around the eyes and sinuses from allergies, but they get a lot better with the Sharp turned on.

nomoon · Post by **nomoon** » Wed Aug 15, 2007 9:38 am

The electrostatic filters are best for extremely small particles like smoke. However allergens and dust bunnies tend to be much larger. The efficiency of electrostatic filters drop off quickly as soon as then begin to get dirty, so they require frequent cleaning in order to stay efficient. They aren't the best for eliminating dust bunnies. They will also produce at least some ozone which irritates my lungs.

However, all HEPA machines require a fan, so there will always be some noise. The Honeywell HEPA machines are incredibly loud. I bought their standard model and it shook the windows. I used a small "quiet" model and it was still unbearably loud. The Whirlpool Whispure HEPA machines are MUCH quieter, especially run at low speeds. The outer charcoal filter is replaced every few months at around $8. The HEPA filter gets replaced every 1-2 years at around $70. I have two in my house and they are extremely good at eating dust bunnies.

There are some machines which use a HEPA filter and an ionizer. I've used a Hunter machine, though I couldn't tolerate the ozone.

If noise is an issue, then I'd suggest buying a large unit and running it slowly. You'll get the same cleaning ability by buying a small unit and running it at full speed, but it will be MUCH louder.

MoJo · Post by **MoJo** » Wed Aug 15, 2007 12:26 pm

I'll say it again, the Japanese units are much quieter than the American ones. My Sharp unit is silent from >30cm, closer than that there is very slight fan noise. I'd say it is probably about the same as or less than a Nexus 120mm at 5V. Quieter than even a WD5000KS or my central heating.

The filters only need to be changed once every six years on average, according to the manual. I have only had the unit for three years.