The edges of the hypoallergenic filters that I purchased with my Cpap are sealed shut. That is likely necessary. If you cut out filters from those larger furnace filters, this might expose tiny particles from inside those filters that migrate out along the edges where you cut . Those particles could end up being sucked up into your cpap and blown into your lungs.
Foreign bodies in your lungs could cause some nasty problems. I don't recommend it.
[quote='surferdude2' pid='83049' dateline='1410494659']
I bought a pack of 12 filters at my local Lowe's store for use in the floor registers of my forced air heating/cooling system. The filters measure 4" X 12" and appear to be of the same material and thickness that my ResMed S9 filters are made from.
I figure this pack that cost me less than 4 bucks will make approximately 144 ResMed size filters and allow me to change filter daily if I so choose. That's roughly 3¢/filter! They're made by a company called Web Products, Inc., in Kansas City, Kansas. The package says they are made from self charging electrostatic material that will trap dirt, dust, smoke and pollen size particles.
Google
Web Vent Filter and click on the Lowe's link. I think Home Depot has the same ones too. You can see what they look like. I can't see why this wouldn't be a good deal better than paying the DME price for these things, which encourages you to squeeze as much life out of them as possible before changing. Changing daily or even weekly could be better.
[/I figure this pack that cost me less than 4 bucks will make approximately 144 ResMed size filters ]
Beware
The edges of the hypoallergenic filters that I purchased with my Cpap are sealed shut. That is likely necessary. If you cut out filters from those larger furnace filters, this might expose tiny particles from inside those filters that migrate out along the edges where you cut . Those particles could end up being sucked up into your cpap and blown into your lungs.
Foreign bodies in your lungs could cause some nasty problems. I don't recommend it.