I order air filters online, because they are cheaper.
In the store, the air filters are around $15 each! Online, I can find them for $10 each, and that is a significant amount of savings.
I buy air filters that are made for homes that have several pets. I have several pets in my house and it is crucial to make sure that the dust and dander don’t cause too many problems for my dust irritations. I do have a mild dust sensitivity to my cats, however it does not keep me from having them in the house. I will happily deal with sneezing and coughing if it means I can have my pets. The whole home air purifier works out very well and the air filters do a good job too. I change the air filters once each month! Since I buy the air filters online, I usually get a box of 12 so I can change the air filters every 2 weeks. I used the last air filter from the box Last month and it was ripped in half. I was bummed out about the ripped air filter, because I had already thrown away the old one. It had mayonnaise and mustard from cats at supper time and I could not get it out of the trash. I could not use the air filter that was ripped in half either, so I had to go to the hardware store and pay a premium fee for a one air filter from the store. They got me for 20 bucks, because they only had charcoal filters that were made with HEPA air filtration technology.