My brother worked for the local HVAC company.
He often told me that if I needed air filters, he could get them for me at a discount.
I had just used up the last of my furnace air filters, so I called to see if he could get a case of air filters for the furnace and the air conditioning unit. I told him the make and model of the HVAC system and he said he would see what he could do. Several days later, he showed up at the house with two large boxes. He told me a case of air filters from the HVAC company, contained twelve air filters. What I bought at the home center was a case of six air filters. I used a box a year, and bought new air filters the following year. I asked where I needed to keep them and if they had to be kept dry. He nodded and said they should be in the basement or in the garage if it was heated and air conditioned. The air filters would be picking up on the humidity and it could ruin their integrity. My husband found a place in the basement for the furnace air filters, but he didn’t want the AC air filters there. I had to clean our my pantry to find room for the air filters for the air conditioning unit. I thanked my brother for his help, but I knew I would go back to using the air filters we bought at the home center. It was more expensive, but we didn’t need to worry about not having enough space to store them.