Hello: I believe they come in packs of 3 in the store. However, I ordered 8 filters online and they came individually wrapped. I guess it depends on how many you need.
We test our residential filters at 295 FPM (feet per minute). For a 20x20x1, that would be 819 CFM (cubic feet per minute).
These filters are sold as single filters.
Takes 30 secs to install. No he won’t be mad!
There is no expiration data on a pleated filters as long as they are kept clean (in the shipper carton).
Mine is a slide in and it works for me
The higher selling volume items typically have a shrink wrap. Your size id not very common and that my be why it was not wrapped.
You have purchased one of the most efficient filters sold in The Home Depot system. But in most HVAC systems there is enough fan capacity for enough air flow. That said you should check the filter every 30 days and change them at least every 90 days.
I do not know. I suggest you look on line or call the store.