Yes, they can be had in cooling-only. I think that the heat pumps are a little more expensive than cooling only, but not much. I can not comment on the relative efficiency. The heat pumps are mechanically more complex so they have more failure modes. I have three multi outdoor units for my seven room house. The reversal valve crapped out on one of mine just before the one-year warranty date. (Note to you AC guys, it stuck in heat mode and would reverse if I tapped on the valve with the butt end of a screwdriver.) I do not think that is a big consideration, but you might want to discuss that. What is the advantage of heat pumps to you? Maybe a lot and maybe none. Do you heat with oil, gas or propane? You can compare your heating costs with your current fuel and electricity rates and decide if you want to heat with heat pumps in relatively mild, but cool, weather. There is a cut-off temp where they fail to perform well when it gets colder. You can zone your heat when you are using them, adding more economy, heating only the rooms are sitting in to comfortable temp and leaving your main t-stat set lower. (This gets a little complicated if the t-stat is in a room that you are heating with the mini split.) Tip: when heating with high wall or ceiling units, you will probably want to turn up the blower manually higher than its programmed speed to keep the heat near the floor and not accumulate near the ceiling. On the other hand, your ceiling paddle fan will take care of this as well if you have them. One thing you might want to keep in mind. I can say that the Mitsu (and perhaps all brand) multi are less efficient than the 1:1 units and they do not do as well as the single units with heating at low temperatures. For the former, I think it stems from the fact that the compressors only throttle back to a certain percentage of max. For example, a single unit might be rated at 9000 BTU. If you only need a little cooling, and assume that they throttle back to 10%, you can efficiently get 900 btu out of them running constantly with no on/off. Your tri unit is probably 22,000 btu and can throttle back to 2200 btu with the same assumption so your compressor will be flicking on and off more often which yields poorer humidity control and not as even cooling. Please, keep in mind the relative nature of my comments. These things all work really well compared to window units and compared to central forced air. Be sure to consider all of your alternatives for the installation. In addition to wall-hung, you can have floor mounted, short ducts to hidden units and ceiling-mounted. That all costs more though. You have probably seen the pictures of installations with the plumbing straight through the walls to the outside of the house. Mine are run inside the walls to underneath the house. Again it might cost you a little more, but talk about it with your contractor. You should look at the MItsubishi, Sanyo, Toshiba and perhaps, other web sites to get some more information about their equipment alternatives. Your contractor should be willing to discuss all of this at length with you since you are making a big investment. I hope they can evaluate your cut off point for economical heating with the heat pumps vs. your hydronic heat. They should be able to estimate for cooling only vs heat pumps. The price difference might be trivial, however.

Yes, but they will need to be correctly chosen and placed so that they will function well. May or may not be cheaper than a ducted system. It will provide zone control so you can heat or cool only the rooms needed and they are very efficient, at least the inverter sets are. You need a professional experieced with installing these as they are quite different and they will need to be sized properly. I cannot guess at BTU capacity but from your discription you might be looking at one dual head unit for the suite and living rooms and a triple head unit for the smaller bedrooms.

The ducted systems are great when you would like the air handler to be concealed. The only issue with the ducted systems is that you MUST have an installing contractor that is capable of configuring the ducted systems AND has the equipment to do so. Unlike the ductless systems, these use short ducts to deliver the air and return air to the air handler. Also, unlike conventional ducted systems, these are 100% variable speed and microprocessor controlled. That said, the ducted systems must be configured to operate at a measured external static pressure to deliver the correct amount of air. This is not a big deal if your contractor is qualified to do it. Just be careful about "shade tree" HVAC contractors that will not be able to configure the new systems. Also, if you have to go back later and ask one of the more expensive trained contractors to come back and fix what the "shade tree" did, it might be a long wait and an expensive bill. It's always better to check references and make the right decision on the front end. Please feel free to check out some articles on ductless split systems on my blog HERE. Also, please reply if I can help further.

Commercial use is an ENTIRELY different ball game. In the HVAC sizing world the HVAC system must be sized for the load of the structure on the highest load day considering ALL loads. Commercial kitchens are heavy loads. Atlanta is a heavy load climate. If the equipment is sized for square footage type load with no consideration of Kitchen equipment, not to mention people load on the structure the system will not keep up. People who like to be comfortable will flee your establishment under these conditions. In the commercial realm when you rent, you merely rent a shell of a building. Renovations are the responsibility of the tenant in nearly all commercial renting contracts. But this varies... it depends on the contract. Some will build to suit as well as maintain various aspects of the building, but that is not the norm. This is likely why you have no HVAC systems at this place. The former tenant may have replaced them at some point and when they left this building for probably better lease costs, they took the HVAC systems with them. Either that or the systems were stolen. My personal opinion on mini splits for a restaurant would be to skip it. If it were to add these for additional spot treatment of hot areas that could work. The biggest problem with mini splits is in nearly all cases of their use it requires more equipment... which in turn leads to more maintenance costs. If you do not maintain a mini split in a commercial environment: 'IE: greasy kitchen / restaurant atmosphere' the mini split will not work for very long. 'There is no machine that comes with a warranty that doesn't require you to pay for maintenance.' Maintenance related failures are not covered by ANY warranty. I know this information is not likely what you want to hear, but you stand a better chance of wasting money on some half baked solution that will not work. Now the picture will be much clearer why so many businesses or start ups fail. Business is tough... you are required to make wise decisions otherwise you will not survive. Your best bet and wisest decision is to locate a few select 'commercial' specialty companies that specialize in HVAC for restaurants. If you do not tackle this problem the right way it will bite you once summer arrives. Another option may be to look at leasing options of the HVAC equipment. In these kinds of set ups you merely pay a rental fee for the HVAC equipment and you don't own the equipment you merely lease it much like most do on the building that houses their business. Under this type of contract you want to make sure that maintenance costs and servicing are included under the terms of the lease. That way it will be one less headache you have to concern yourself with. Realize under a leasing arrangement you can't just pick any HVAC provider. These are typically specialty type arrangements... you'll have to search for them. If you can't afford to do it right. It will shut you down in short order. I wish you well and I hope you heed my advice.