Thread: VC filtration performance

SWMBO recently ordered a cordless cyclonic action VC (a well know brand that does a fair bit of sell promo on the TV) and I thought it might be worth seeing how good it was at filtering dust from the air.
After performing the test I decided to compare it against a few of the other VCs I had filtration efficient for on my data base.

Most of the 20 or so VCs I have tested have negative measured filtration efficiencies which means they are net fine dust makers i.e. they pick up most of the visible dust but spew out more finer dust than they pickup. The reasons for this are complex but include things like; the mincing action of the sucking process and poor quality of the filters and leaks. All of the used VCs also had contaminated motor cooling loops which make comparisons difficult.

So as not to clutter the graph too much I restricted comparisons to only a some of the positive efficiency VCs that look like (at east externally) they had been well maintained.
UHEPA = 5 year old HEPA filtered SHOP VAC - well known expensive brand -
UHEPAR = the same VC as the UHEP after servicing and refurbishing
NHEPA = A brand new HEPA filtered SHOP VAC - same well known expensive brand as previous two
Cyclone = New cyclonic action VC
UB = used, budget level, popular brand, Barrel type workshop VC
UHEPA2 = same brand as other HEPA VCs but 6 months of

The used VCs I have chosen appear to have
VCperformance3.jpg


The first thing to notice is the performance degradation of new HEPA filtered VCs (NHEPA - green line) down to the orange (UHEPA2) and the darker blue (UHEPA) lines.

Servicing and refurbishing UHEPA improved it performance considerably, see red line (UHEPAR) but it doesn't get back to its original performance especially for particles <1 micron
UHEPA was about 5 years old and externally it looked like it had been well maintained - according to the owner it had been subjected to medium level, intermittent use, mainly on hand power tools.
I quickly identified UHEPA had several small leaks on the seals. Its motor cooling loop was also very dirty.
Then UHEPA VC was cleaned, had the seals replaced, and the motor cooling loop was vigorously blown out with a compressor.

UHEPA was about 6 months old and according to the owner was also subjected to medium level, regular use, mainly with a Festool Sander.
Interestingly the >5 micron and 0.3-0.5 micron range efficiencies were almost the same as the much older UHEPA VC.
It's motor cooling loop was also very dirty
Unfortunately I did not have time to service UHEPA2 and retest it.

The new cyclonic action VC claims to "remove dust particles down to 0.5 microns" but it's only removing ~87% at that size.
However I does much better than I thought it would, being better than the UHEPA.
It will of course be interesting to see how the cyclonic action VC performs as it ages.