I really love the feeling of quality this little thing exudes and it’s amazingly compact compared to the alternatives, however with the supplied G4 filter it is only 65% effective at filtering particles sized 1 micron and below.
Since I’ll be using MDF quite a lot, I decided I wanted to increase this protection by adding a secondary F9 filter behind the G4 one to improve the effectiveness at filtering 1 micron particles.
Obviously adding a second filter will decrease the airflow through the device, but here the amazing power of the little MC760 comes in handy.
The MC760 has the capacity to filter 760 cubic metres of air per hour and Arcol, the manufacturers of Microclene air filters state that the MC760 is suitable for rooms up to 76 cubic metres.
This figure is based on their contention that although COHSE advice is to change the air in a dusty workshop 6 times an hour, 10 times an hour is better.
I agree with them that erring on the side of caution is always best, so I’d like to ensure the filter still changes the air in my workshop 10 times an hour, so any modification must not reduce the airflow below about 150 cubic metres per hour (my workshop is only about 15 cubic metres – 2.5m x 3m x 2m).
I’ve been speaking to Ron at Acrol and queried whether I could fit a 292mm x 292mm x 25mm F9 filter from Jasun Filtration behind the G4 filter.
This filter claims 95% effectiveness at 0.6 microns, so it should improve my chances of stopping the small stuff.
(There is more detail on the specific filter that I’m considering – part number NP911212, – in PDF format here and a selection of other filters that would fit here – I can’t find an updated PDF for their new UP911212 part number).
He’s responded stating that he wouldn’t see a problem with that and that air flow would be around 400 cubic metres per hour with both G4 and F9 filters fitted, or 460 cubic metres per hour with only the F9 filter fitted.
I was concerned that I might be placing too much load on the motor but Ron says it should be fine at those airflows.
Obviously 400 cubic metres per hour is more than enough for my needs, so I’ve been on the phone to Jasun this morning and spoken to the very helpful Len, who has pointed me in the direction of the UPC911212.
(The UP911212 is the new name for the NP911212 and the extra C designates a plastic frame instead of a galvanised one, which should be less likely to scratch the paint and is a little cheaper).
I was only going to order a couple, but Jasun seem to have a small delivery surcharge for orders under £50, so I’ve ordered 6 for £54.21 rather than pay the extra £15 (ordering 5 would have cost me £63.18 so I’m saving money!)
Jasun’s online commerce site can be found at www.jfilters.com and although it’s a little hard to navigate in places, searching for UP911212 or UPC911212 should get you what you’re looking for.
As an aside, interestingly (if only to me!) Jasun were previously based in Sussex (where I live), but moved to Somerset (where I grew up) in 1987.
Update 15/06/2012: I’ve now received the Jasun filters – see this post for more details