Yeah that's R22 and while that is a builder grade Trane unit that is probably out of warranty by now... typically those were sold with 5 year parts warranty. Because R22 Freon was already obsolete by 2013. With that said, this condenser 'could' last another 10 years, provided the coil repair work is done appropriately. The replacement coil needs to be a coil suitable for R22 / any coil can be retro fitted to work, but skill is required in choosing the coil. Typically home warranty companies are known for tom foolery. If the condenser was a dry condenser (nitrogen gas) it would say it was on the data plate in some manner. That's the down side in anything Trane or American Standard because they were one of the last manufacture's to switch over to R410a refrigerant. The R22 conundrum only effects you if there is a leak... otherwise it doesn't matter much. While the cost for it will only go up now that production has ceased, it's serviceable life is still around another 10 years or so. Without United Technologies Corporation heavy investment in R410a AC equipment development we would be no where near where we are today. R410a equipment has been available now for almost 20 years if you can imagine that.

The load calculator is sensitive to the inputs your provide. If you enter something inaccurate, it can swing your numbers one way or the other. So, get the inputs as accurate as you can. In particular, you might be overstating your actual insulation ratings. I shared my local calculations with dealers that came to my house. I told them that my own Manual J calculations called for a 32K BTUs of heating, so why are they recommending 80K BTUs at 80% AFUE = ~64K BTUs. Two of them decided to do their own load calculations and came back with smaller equipment including 60K BTU furnaces to match my 3-ton a/c system. So, ask your dealers why they are recommending such a big furnace. It's maybe because you told them that your back rooms weren't getting enough heat, so they automatically increased the furnace size. Maybe the solution was to seal/insulate the ducts or re-balance the air flow.

Furnace technology has improved for efficiency, but that's a matter of how much gas needs to be put in, to get how much heat out. 25 years ago, most furnaces were oversized all the same, larger (and so providing more heat) than structures needed. If your existing furnace has a sheet metal exhaust stack, it is 80% efficient. The 120K label is usually input, so at 80% efficiency, it produces 96K BTU output. A 100K BTU furnace that's 96% efficient would use 20% less gas to produce the same amount of heat. But to install a higher efficiency furnace where an 80% was previously located requires providing a new "exhaust" system of plastic pipe, that will cost more. If you're not the one paying for the heating, it wouldn't necessarily be worthwhile unless you want more environmentally friendly equipment. As I understand, "block calculations are a short cut using the structure overall rather than room by room. If the exterior walls and windows/glass are reasonably measured, it should give a close approximation. There's nothing brand specific about any load calculation, it is what it is. The commercial software the HVAC guys use is for any or all equipment, it's simply how much heating or cooling needs to be provided to the structure based on its location and heat gain/loss characteristics. As before, if the HVAC person told you that the calc was equipment manufacturer specific, that's baloney. It may have been who supplied the software for their use but a calc is a calc. So much per square foot is also baloney. There are no rules of thumb. If you want to believe that, then you're ready to believe a 60 year old house down the street with no insulation and lots of single paned glass, your house. and the newly built well insulated house down the street in the other direction with triple glazing would all need the same size furnaces and AC because they're the same number of square feet inside? Of course not.

Michael, The furnace data plate tag picture you posted in the first post shows a 1989 manufacture date for the furnace. The picture above with the coil and the drain pan shows a metal drain pan. What does metal do? Rust. Clearly visible in the picture above. Metal pans get holes (condensate leaks) not cracks. Due to the age of the furnace, the AC could be just as old? 34 years is a long time in HVAC. I don't know that a home warranty company would offer a fix to this or not. I think most would find some way to deny coverage so they can get out of it. Why home warranties and HVAC rarely go well with one another. Most of the time to replace that pan would require refrigeration work to remove the coil to get at that pan. If the coil is even only 20 years young due to all the changes in coil sizes (physical size of the coil, not tonnage) finding a pan that will fit could be a big challenge. Calling the manufacturer of this coil looking for a drain pan will most certainly get a round of laughter. They will say things like: we haven't made those pans in 15 years. I suppose you could look for someone to make a custom pan, but pulling the coil doing the work will probably lead to a failure of the coil itself (freon leaks). Then the money you spent on a new custom drain pan is up in smoke. The real path forward is to replace this system in my opinion, that is *if you determine the drain pan has a hole in it due to rust.* Even if the drain pan is merely clogged, the age of the system tells me the path forward is replacement. Start saving up for it. I service the Katy, Texas area.