Air filter..which one?

[lastminute]

..the Record AC400 or Microlene MC200....price difference?

Thanks

Gerry

 

[Fromey]

The former looks significantly larger than the latter. Also, I can't say I'l impressed with the filtering capacities of either. Microclene claim "Removes 95% of 1µm (micron size particles), 65%of particles 0.5µm (micron)." Not as good as a true HEPA filter. I'd go with a domestic true HEPA air purifier. e.g., http://www.aircondirect.co.uk/ElectrIQ_ ... n.asp?PID=

 

[lastminute]

...thanks Fromey..it looks like something that's best suited to an office ( and cheaper!!).. would it be ok for a small workshop?

 

[PeteG]

..the Record AC400 or Microlene MC200....price difference?

Thanks

Gerry

Hello Gerry. I have the Record AC400 which hangs from the ceiling and there is a very noticeable difference between having it on or not, and I regularly clean the rear filter to try and help it work at it's best.
I spent a couple of hours yesterday cleaning the workshop, sweeping, vacuuming, and using an air gun/compressor to blow dust off the strip lights, machines, and from all the nooks and crannies etc. The AC400 was on all the time and I left it on whilst I popped out for an hour or so, up on my return, the air/atmosphere seemed fine, but I still had a fine layer of dust which had settled over everything. Perhaps it isn't big enough to cope with a major clean up, or the layer of fine dust which had settled afterwards is normal, I have nothing to compare it to, but I still believe it's done a good job over the past year.

The former looks significantly larger than the latter. Also, I can't say I'l impressed with the filtering capacities of either. Microclene claim "Removes 95% of 1µm (micron size particles), 65%of particles 0.5µm (micron)." Not as good as a true HEPA filter. I'd go with a domestic true HEPA air purifier. e.g., http://www.aircondirect.co.uk/ElectrIQ_ ... n.asp?PID=

Hello Fromey Could you have an AC400/MC200 at one end of the room and an air purifier at the other? The price looks right for the one in your link, but would it cope with the amount of dust caused after a couple of hours with MDF on the router?

 

[Stu_2]

I use an AC400, which works well for me, but I've got a small workshop. I doubt that air purifier was ever designed to cope with a workshop environment.

 

[Fromey]

The caveat is, I don't have a dedicated air filter in the shop, so can't talk from experience. At the moment I'm experimenting with an old domestic HEPA filter I had kicking around. It seems to work well, but I only have a 10' square shed, so not that much volume, I only do hand work, plus I have no way to assess particle clearing.

My understanding is that the small particles, below 0.5 microns are the most hazardous. They don't settle out due to small air currents and Brownian motion. It's these blighters one mainly wants to eliminate. A true HEPA filter (not a "HEPA like") is specifically designed to do that; by definition it removes, "at least 99.97% of airborne particles 0.3 micrometers (µm) in diameter".

Thus, you need a HEPA filter attached to a fan that can move sufficient volume in a housing that doesn't leak around the filter. It's not rocket science. I seriously doubt the "professional" filters justifying the price. Perhaps the motors are rated for longer life. Call me cynical, but I see outrageous markup by scientific equipment suppliers all the time; they'll often source a domestic item, label it "scientific" and then add a 500% markup.

The domestic air purifier I linked to is a true HEPA (I asked the technical reps at that site), so should work just fine as long as it can shift the air volume of your shed. Would it clog up with dust and short circuit or some such? Don't know. Hard to tell unless you open it up or just use it and see.

 

[PeteG]

The caveat is, I don't have a dedicated air filter in the shop, so can't talk from experience. At the moment I'm experimenting with an old domestic HEPA filter I had kicking around. It seems to work well, but I only have a 10' square shed, so not that much volume, I only do hand work, plus I have no way to assess particle clearing.

My understanding is that the small particles, below 0.5 microns are the most hazardous. They don't settle out due to small air currents and Brownian motion. It's these blighters one mainly wants to eliminate. A true HEPA filter (not a "HEPA like") is specifically designed to do that; by definition it removes, "at least 99.97% of airborne particles 0.3 micrometers (µm) in diameter".

Thus, you need a HEPA filter attached to a fan that can move sufficient volume in a housing that doesn't leak around the filter. It's not rocket science. I seriously doubt the "professional" filters justifying the price. Perhaps the motors are rated for longer life. Call me cynical, but I see outrageous markup by scientific equipment suppliers all the time; they'll often source a domestic item, label it "scientific" and then add a 500% markup.

The domestic air purifier I linked to is a true HEPA (I asked the technical reps at that site), so should work just fine as long as it can shift the air volume of your shed. Would it clog up with dust and short circuit or some such? Don't know. Hard to tell unless you open it up or just use it and see.

Hello Fromey and thank you for the explanation So do you reckon the fine layer of dust that settles even after I've had the air filter on for a few hours, are particles smaller than 0.5 microns? Would make sense if they are. My shed fits within the size of the purifier in your link, and for the amount of time I spend in there, £50.00 could be money well spent!

 

[DiscoStu]

This is an area I know nothing about, but would the Honeywell not just clog up quickly with the larger particles?

 

[Fromey]

I expect all filters will clog. Typically a prefilter is installed to catch the larger particles and can be periodically cleaned. Even so, the HEPA filter will eventually clog, which is why they are disposable and you can buy replacements. In my experience, HEPA filters themselves are fairly robust, so you can use a vacuum cleaner and gentle brushing to extend their lifetime. My main concern with workshop use would be how well the non-filter components withstand clogging. Again, I think you'd have to actually look at the Honeywell filter and/or use it before you could evaluate it. At the moment I don't have room in my shed to house it, otherwise I'd give it a go.

As to dust particles, the limits of normal eye resolution is about 0.04 mm (40 microns). Thus, all of these harmful dust particles are completely invisible to the eye. That makes it rather difficult to evaluate the efficacy of any filtering device (we largely have to trust what the manufacturers say). Since I have access to microscopes and millipore filters, I might investigate the methods of assessing particle count and see if I can do some experiments on it.

 

[RogerS]

If dust is settling then either there was an awful lot to begin with and/or there is not enough volume of air being shifted by the air filter for the size of room.