re: HVAC Filter question

Here's some food for thought. You can buy permanent filters that can be hosed out monthly or whenever you would change out your filters in the return air grill.

They do cost more up front, but last for years if you don't bang them around. I ordered 2 for where my wife works when they first opened the office in an old building that was refurbished.

One cost $75 and the other cost $50 to fit the units they had installed. Once a month I'll pull them out and just hose them with the garden hose and let them drip dry and replace them in the grill. You will save money in the long run doing this.