Filter times

Why after I piurchased the filter am I hearing that if I am using mostly fiberbosard that it will fill up in bout 2 weeks? this does not make sense and please ttell me about prefilters

Filters of every kind are consumables. Some types can be cleaned but others like an oil filter are not and require replacement.

It depends on the material you are using, and the draft board produces a lot of particulate that face loads the filter.
So a pre-filter would be a layer of cleanable or disposable material to extend the life of the filter element.

I don’t use a filter because of the expense, and vent directly outside instead.


You can fill the cartridge in a few hours with the wrong material, like MDF and Draftboard, or Proofgrade medium ply (which has a draftboard core.)

There is no pre-filter available, but if you use the search function, several members have shared detailed of how they implemented one.


Pre-filters might not help you enough with Draftboard or MDF. The problem is not particles, it’s the glue in those products, which becomes airborne when lasered and lines the pores, reducing the diameter of the tiny pores, and ultimately making it impossible for air to flow through. It’s going to happen the same with any filter that has pore sizes small enough to filter smells and make the smoke safe enough to breathe.

Your best bet is to vent out the window if you have to cut draftboard or MDF. Otherwise, hardwood is a much better bet and the filter lasts a lot longer.

If you do want to try to pre-filter though, no harm in it. There was a Honeywell paper filter (like forA/C intake) that a couple of testers tried out that might help a little bit. Just cut it down to fit.


This is the type of pre-filter that I am using. It’s an inexpensive way to catch some of the particles that contaminate the main filter cartridge, thus extending the life of the cartridge.


I’m sure the percentage the vaporized glue that deposits contributes, but the occupation of physical space by the ash is a factor. At one point it alone occluded my exhaust fan. Touch it and it crumbles to a fine dust. That residue will accumulate along with every other chemical constituent that might result in vapor deposition.
Bottom line, a filter’s function is to remove impurities, and they come in a spectrum. Their combined effect on the filter is cumulative.


Since the conversation has died down and we’ve replied to your email, I’m going to close this thread. For those interested, you can read about the estimated lifespan of filter cartridges.