TriStar Filter System:
As others have pointed out here, TriStars have several filters, including the filtration capability of the bags. Each filter in the quadruple filtration system serves a different purpose:
- CLOTH BAG: This is the main dirt collection element, capable of filtering on its own. TriStar's instruction manual states that the cloth bag can be used by itself, without a paper bag inside it. I personally do not recommend that practise; I find that the inside of the canister gets dirty when the cloth bag is used without a paper bag. The cloth bag should be replaced periodically; if it gets a hole in it, or if the rubber sealing gasket around the top gets hard, it's time for a new one. It should be washed or vacuumed periodically, at least every six months.
- PAPER BAG: This goes inside the cloth bag. Should be replaced when it's full, or sooner.
- MOTOR FILTER: This is a washable, easily replaced foam filter element that snaps onto the motor's housing. To access it, open the bag door, remove both bags, and look towards the rear of the machine. I have two of these filters, which I alternate. When I change the paper bag, I swap the filter in the machine for the other one. Then I wash and dry the filter I removed from the machine, and put it away for the next swap. If you have an older Compact with the fibreglass filter, you really really repeat really need to replace the fibreglass filter with the new type. Fifty-year-old fibreglass sheds glass particles, and the older machines do not have an afterfilter to keep those particles out of your lungs. The fibreglass filter should be kept for display purposes only.
-AFTERFILTER: There are two different ones available. There is the standard afterfilter, which is a simple foam element held by a plastic frame. It does a fine job if you have no allergies. It should be washed every bag change. There is also the Filter-Fresh, which Bill has kindly described above. It is essentially equal to HEPA filtration.
I can tell you that it is definitely worth keeping up with all the filters in a TriStar. If all the filters are present and in good, clean condition, a TriStar does not have any "vacuum cleaner" odour when used, and dust does not reappear quickly after you finish vacuuming. A room that has been vacuumed with a TriStar actually smells fresher and better after you're through. I didn't believe that claim when I first read it, but my own experience is that it's true.
