I don't know what Trane has to do with it. I have a Mitsubishi Split in my lanai.
18,000 BTU with dry and heat settings. I love it.

Mitsubishi AC
 

We also have the Mits unit in our enclosed lanai. Have the ceiling unit in the lanai and also put a wall unit in the garage. Both share an up sized outdoor unit. Installed by M&S. Did great job.
And the electrical bill did not increase much. Maybe 15-20 dollars per month.
I keep thermostats on both set at about 78-80. Garage is cooler a lot than before, but more importantly it is drier. Have an insulated garage door. Garage faces west.
Electrical work was included in M&S quote.

I just had Munns install a Mitsubishi unit with the grills in the ceiling and it was around $12,000 installed for a very large lanai. I will also spend $1000 on insulation. It was a dollar a sf so the lanai is around 1000 sf.

Mitsubishi is the best mini split. I sold and serviced all brands fo 40 years.

Trane
 

Lowe's states it is a Mitsubishi unit that Trane puts their name on. Lowe's wants $3900 to install, unit is 15k btu's.

We've had a Mitsubishi unit on a 12 X 20 enclosed lanai for over 10 years. Private company installed it. Cost was 3,000 then. It works great and the advantage is you can heat or cool only when you are in your lanai as opposed to having your central air ducted into the lanai. We have acrylic windows. Our lanai ceiling was insulated when the house was built.

I have the Mitsubishi unit installed in my 10'x30' lanai. This unit was installed by the previous owner, who did the lanai conversion. My lanai unit has a double-wide entry to the main part of the house. The lanai also has two fans installed. In the three years I've lived here, I don't think I've ever used the Mitsubishi unit, the fans are usually more than adequate. I've tested the Misdubishi and it works fine, I just don't think I need it. BTW, I dislike air conditioned units set very low (<75 degrees). Your needs might be different. I don't know the cost of the Mitsubishi unit- if it's not a significant amount for you, then go ahead and install for peace of mind. If you need any more info, just PM me.

Mitsubishi Mini-Split
 

I highly second the previous posters' recommendations of M&S Air Conditioning to install your Mitsubishi system on your lanai. They did ours and did a great job. We had them install a cassette unit in the ceiling rather than a wall unit. It is more money but looks and works great. Give Jim Macdonald a call @ 352-314-5004. He will explain your options and size the unit for your space. Even if you chose not to go with them at least you will have a second opinion as to what is best for your space. Our 14x14 lanai with double pane windows has an 18,000 btu cooling/21,600 heating spec which is 22.3 Seer.

I have a Mitsubishi split unit formula Lanai. It is wonderful and it it also reduces the load on the AC for the rest of the house. I bought my unit thru Munn's, they did the installation. It was extremely well done and I thought reasonably priced. The work passed the electrical inspection and the county building inspection. The inspection was handled by Munns. We highly recommend them.

We expanded and enclosed our lanai. It is a 17'x20' air conditioned room using a 1.25 Ton Mitsubishi split unit. It was installed by Kalos. They did a very professional installation. We have been most happy with the results.

If you're a handy person, or have a friend in the business. eBay has many different units and sizes brand new for under a $1,000. I just read on Facebook Villages Talk a fellow said he has this unit, it a Kawasaki compressor and it works great.

AUX MINI Split Air Conditioner Ductless Heat Pump System w/WIF12000BTU 115V12ft...$529.95

AUX MINI Split Air Conditioner Ductless Heat Pump System w/WIF12000BTU 115V12ft 608442783385 | eBay

https://i.ebayimg.com/images/g/11wAA...VD/s-l1600.jpg

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Kalos installed my Mitsubishi split, had the best price and did a great install, I would recommend them

Mitsubishi Mini-Split in Lanai
 

I had a 1.5 ton Mitsubishi mini-split installed three weeks ago by United Refrigeration, Ocala. My lanai is 30' x 12' and has lots of vinyl windows. So far it has been wonderful and if I keep the doors open between the house and lanai it all works well together; I am now able to keep each thermostat one to two degrees higher. Total cost just under $5k. If insulation is needed above the lanai, that would be extra charge. Note, mini-splits in lanais are only permitted in Sumter County (not Lake or Marion).

We just had Kalos install a Carrier cassette system in the ceiling of our 35x12 glass enclosed lanai. It works great and Kalos did a great job.

We interviewed several, and decided on Munns. We just bought and moved in early Dec, had this done..I think late Jan/early Feb, but so far, VERY PLEASED, AND, they handled all "requirement stuff", as well as permits, inspections, etc. This house was bought 1st with screened lanai, enclosed by 2nd owner, but never added a/c assistance. That = a/c system failing 2 months after we bought (wonder what she did to 'make it work for a while'...our inspector found NOTHING!) SO, we got to buy a new a/c system as well. LESSON LEARNED..... Require the seller to include a home warranty policy. In addition to the a/c, the ice maker in the fridge died, and the microwave died (that was ok, because we were planning to replace all kitchen appliances anyway. We just didn't plan on having to do it so soon, paying for service calls, etc. AND, buying a new a/c system, and needing to upgrade the electrical system (which is probably why the 2nd owner didn't put in a mini split...the 'low class' box barely covered the basic electric in the house. LOVE THE HOUSE, LOVE OUR NEIGHBORS, but the extras that we didn't think needed to be handled, has put a damper on moving forward more, with making this house our home..but, we do love our location/neighbors etc. We will get there soon, we hope