It was installed yesterday around noon. Temp outside was probably about 80 degrees and humid. We set it somewhere in the 70s and left it running for a few hours while we went out. When we got back, it was running well and the air seemed drier in the room but what was blowing out of the unit didn't feel that cold. I should add that this is in an apartment that we rent out. We had to leave, so we turned it down to the lowest setting, 60 degrees, and left it running. We called the tenant and asked her to call us and tell us whether it was working properly by the time she got home from work. From what she said, it sounded like it wasn't any different. We live an another city, so it's a bit difficult for us to get back up there to check on it. The apartment is a small studio, and it's a 7800 BTU Friedrich, so I believe it's the correct size. We had the store install it. I suppose we would need to use a separate thermometer to determine whether the room air is cooling to the right temperature, but subjectively, it didn't seem like it was.

I have 2 4 ton units. The math says just 1 is enough. 1 is upstairs, the other downstairs. Instead of doubling the units they should've been divided. I think 1 3 ton downstairs and 1 2.5 upstairs is plenty. We never set the thermostats higher than 65° in the winter and 68 in the summer. We like it a bit cool. We also use the fireplace when it's really cold. We have these little space heaters too. In an emergency we have a kerosene heater. We have a maintenance plan with them so they come out every 6 months or more if we want. But the techs never once said anything about rust forming on the coils. On top of that they're supposed to clean the units. The unit in the attic had nearly an inch of mold on the coils. The last guy that came out was honest and he took pictures and showed me. I believe if they would've done their job, my attic system wouldn't be filled with mold and rusted to the point that it could blow out. I'm handicap. I've had 12 surgeries on my back. Every single tech that came out was told. Because of their laziness and not doing their job properly the coils are going to go out. I found out from another service that there was steps they could've taken to prevent the rust and the mold isn't that difficult to clean. At the very least they should've told me about it before it became an issue. But now they want to replace them with the same size system and the other service said I didn't need 2 4 ton sytems. He said 2 2 tons or 2.5 tons was plenty. I asked about the 3 ton and a 2 or 2.5 upstairs, he said that would be more than sufficient. My house is 1700 sq.ft. the back porch adds the 100 sq.ft for 1800 sq.ft. when we asked them why they gave us 2 4 tons they have no answer. When we asked to go to smaller units to save money they said I should replace what I have with the same system. I explained the math and 1 4 ton was plenty for the whole house and they gave me bs about how old it is and they didn't even offer to come out to check to see what I actually needed. The other guy offered. So I guess were just going to have the test done and then get estimates. Before we went to 2 heat pumps, we had 1 oil furnace that heated the entire house. We only had to fill the 375 gal. Tank once a winter then another 100 gal. Most the time we didn't use it all. The oil furnace was ancient so it died. We had 3 10,000 btu window air conditioners and 1 5500 in our bedroom window. So we figured we'd get a heat pump. We thought we needed what they said. But we didn't. I only have about 900 sq ft down stairs and 900 upstairs. Actually it's closer to 1000sq.ft. downstairs and 800sq.ft upstairs. We keep the house a littler cooler year round. So we're always comfortable. Only time the emergency heat came on is when the system downstairs broke down. Now because of its age and inefficiency, it costs more to heat and cool the house. Like I said, we think we're just going to get the test done to see what size system we need and use a different company because we don't trust this one any more.

If the thru the wall unit is rated for 20A, then yes, use the existing 12/2 wire for 240V. Simply take out the 1 pole breaker and replace it with a 2 Pole breaker, making sure the new double breaker is attached to different legs in the panel. If you don't know how to do this, check a wiring book. Then attach the black wire to one breaker of the pair, and the white wire to the other breaker. Place some black electrical tape on the white wire at the panel and the new unit. If the new unit is 15A, then use a 2 Pole 15A breaker. If the new unit is rated at 25A or more, you will need to rewire as well as bigger breakers, assuming you now have 12/2.

If you get imaginative, you might be able to get the Firgidaire to work. The width of the unit is only 19". I think the minimum width specification comes from mounting those accordion folding sides that you see on window A/C used to close the gap on a wider window. Take a look at maybe just using one side, or maybe foam insulation stuffed in instead of the sides things. Mini splits are a HVAC contractor item. As I said, it will cost several thousand including installation. If you have the budget and want to go that way, get a few quotes. Also, what kind of heat do you have? An interesting twist is that some mini-splits can be used as heat pumps as well, which could be a considerable savings if you have oil heat.