You guys probably get questions like this all the time, but I couldn’t find the answers I was looking for going back through the forum, so I thought I’d just ask myself.

Background:
My wife and I bought a townhouse in a Minneapolis suburb less than a year ago. We’ve had a lot of fixes in that year, but we now have a problem with the AC. It appears to be leaking refrigerant, and the charge to find and repair the leak was higher than I expected. The house was built in 1995, but a tag on the furnace panel notes that at least the furnace was actually constructed in 1990. Given the age of the system we believe replacing the AC is probably the best choice.

We’ve had 5 estimates so far and they are all fairly close, but I had a few questions. If anyone can be of any help on any or all of these questions, that would be helpful

1.The furnace still works fine. It does have some rust in the system; don’t know how long it’s been rusty. Wish our home inspector had caught that at closing. The big question for us is this: Should we replace the furnace at the same time we replace the AC? Obviously, the contractor will give us a sizable discount to buy together, but if the furnace lasts a few more years why replace a system that still works?

2.Should my proverbial panties be as bunched about the difference between r22 and r410? Most contractors have offered us the choice. We plan to be in the home at least 5 more years, but resale of the home is important.

3.It’s a two level townhouse with an unfinished basement. Do I really need a variable speed blower? A two-stage furnace?

4.My wife and I are both reasonable healthy, neither of us have any allergies, we have a standard 1” filter. Again, most contractors have given us a choice. How much do we need a media filter?

Those are some of my basic questions. The biggest one being whether we should replace the furnace at the same time. If the economy tanks more, could we get a better price if we waited a little while on the furnace?

Thanks for any advice!

Oh! One more thing. My dad claims he read about a system that could use r22 or r410. I say no system can do both. The old man’s on drugs, right?