Hrm. They no longer make filters for my older portable AC. They're carbon filters, so I doubt DIY is a thing? Hopefully running sans filter works ok.
@JulieSqveakaroo More worried about gunking up the internals. I have an air purifier in the same room for the output
@Doephin
You can always secure a filter over the exhaust as a DIY... it's not the best, but any filter % is better than none.