First, its likely the unit proposed is 12,000 BTU heat and cool, not 1200 so its significantly larger capacity than your previous window unit. Most mini-splits are much more efficient than your window unit so energy savings will be in order, not to mention its a heat pump replacing strip heaters. 12k may be too large, 9000 units are available and cheaper. Also efficiency up to a SEER of 19 and they are VERY quiet. I would stick with a major brand unit, not a chinese import with no parts support. LG, Fujitsu, Mitsubishi, Panasonic and Sanyo. Unfortunatly the american brands have not really entered this market yet, they are much more popular overseas.

not minisplit related but... a metal building with metal studs & fiberglass batts...she is going to have one heck of a utility bill. what I've learned over the years is how highly conductive the metal studs are to the point of derating the fg batts to very low R-values. heat/cold transfers very well from shell to studs. in my hot/humid climate the wall studs condensate through the sheetrock in the late summer. with paneling ...which is thinner..I'd worry about this issue in this small house. the only way we get these homes to perform is to thermally break the walls by putting a foam sheathing board next to studs, under metal siding...and roof. well...there is always foam in the studs/rafter bays but the sheathing is a less cost install. at 1,000 sq ft and two ton minisplit...with all the openings in the paneling tha should have been sealed during the install of the minisplit... I'd run lowest speeds, and seal each opening in the paneling..at each ahu. what is the location of the house? best of luck.

I think the problem you may run into is the refrigerant. The units probably came already filled. When the units were installed, a valve was opened and all the refrigerant went into the piping and the inside unit. When you disconnect everything all that refrigerant will disappear into the air. Around here you might get a HVAC guy to pump the refrigerant out and reuse it whereever you are moving to. where you are, I doubt it. And you will need to have someone add refrigerant at the new location.

Ionized, I am always amazed at the workings of Utilities. As I said, there is a significant rebate presence around the mini-splits to reclaim the heating market lost to gas and oil years ago. Remember the 50's & 60's when the mantra was the "Gold Medallion" home? Total electric! the embrace of that concept, low first cost, led to a huge market in gas conversions. That is the primary market I attacked with the Rinnai Energysavers in New England and we sold a couple hundred thousand of them. I've heated my home with them since '91. In conjunction with the mshp's it is just a great combination. Gas is still the right alternative for heat, but as the compressor bearing technology continues to improve and they get better at hot water it is going to be really interesting going forward. So, today, gas for heat and hot water is the right choice, for me at least. Once cooling gets into the equation the heat side is impacted and we'll have to see where it goes. It's a big market and nothing is going to happen all at once. On the duct work leakage question of interior/exterior things definitely get murky. The thing is, every system has a personality. The exterior mounted stuff is the worst. The interior systems have substantial problems too. It is fairly common where due to leakage you create different pressure zones (+/-) in a home that can actually increase infiltration into the space. Snidely, it is difficult to say it is this cost. The output of the units will vary somewhat with temperature. Actually, the Feds don't even know how to accurately determine seer ratings. When I speak with the Japanese Engineers they say the 25's are closer to 35 seer, but we live where we live, so.... 25 it is. I can tell you that in my home here in the dry dry foothills of CA, I heat with my Rinnai EX22 and a dual mshp upstairs. I have a 25 seer 12 and a 23 (?) seer 15 downstairs. I also run a Rinnai tankless for dhw. My 250 gal LP tank lasted 14 months. The house is 2200sq ft. My highest bill to run the whole place peak of winter and summer (well, lights, heat/cool, the works) has been $85 and we do not suffer comfort wise under any circumstances. In the spring/fall shoulder seasons the bill falls to $35-40. If you are looking for heat, I'd absolutely go with the Rinnai's over the mshp's. From a comfort point, gas is hard to beat. From a technology point with the modulating burner, blower, etc the Rinnai's are the best heating appliance I've seen in 50+ years in the business. You have a decision to make on your 40 yr old leaky ducting. If you can find someone to do the job, do not pay for it until the system meets the CA requirement of a max of 6% leakage. I spoke with a contractor who, in Clearlake repaired a single story raised ranch with 12 outlets. two men 1.5 days, $2,400. I spoke with another contractor who repaired big home up in Carson City, $11,500. Yikes! When we moved west 4 years ago my duct system was beyond salvation and would have been impossible, due to access issues, to repair. I pulled it all our and took it and the five year old furnace/condensing unit to the dump. with my current combination of the Rinnai's and mishap, I am all zoned, net to the space and comfortable. Oh, and I gained two closets by removing the ductwork and also gained the storage under the staircase. Doing what I did is a REAL step, but you need to evaluate the whole package first, break it down and see what is best for your home. Fun isn't it?