The zeolite is reusable indefinitely, though it seems possible that it could reduce its usefulness after a while as a consequence of having “clogged up”. Presumably that’s what the filters are for: to keep dust, pollen, and also other big things that might clog the zeolite pores out of the https://socialtechnet.com/story14266383/examine-this-report-on-philips-oxygen-concentrator