heat pump, central air and heat and a mini split as far as cost of operation? heat pump same as central air and heat except that the heat pump provides the bulk of the heat. this is what I recomend to my clients based on savings compared to electric strip heat. with heat pumps the electric strip is emergency heat and for when temps are 30 degrees..which is not that often for us. central air is electric strip heating only. the most expensive way to heat your home. (espically if you have entergy for your utility provider) mini splits are pretty cool. expensive but fit a lot of needs and great for tight retrofit spots. the condensing unit goes outside like with any set up, but this is where it changes. in each room the air is provided by a wall mounted air handler unit. the condensing units are up to 3 tons. each room would have the ahu..this is what they are calling zones. cost is higher, but you don't have ductwork, so it evens out a little better. with the foam insulation & low e windows your tonnage of ac required will be less. although I don't recomend 'rule of thumb' sizing instead of the ususal 400 to 500 sq ft per ton, your house will be more in the range of 600 to 700 sq ft per ton. oversizing will cost more to operate, wear the equipment out sooner, and will NOT dehumidify. be diligent in finding out what is being spec'd for your home and what options are available for you. some systems will qualify for tax credit, and it is always a good idea to do better than the legal minimum allowed by law (code). in what part of La. are you building? best of luck.

Window/wall units may cost more to run compared to a central system depending on some factors that are involved: 1) The efficiency rating of the window/wall unit vs. a central system. 2) Where the window/wall unit(s) are installed regards to getting the cooled air evenly distributed throughout the living area. 2) People tend to overcool with window/wall units by setting the thermostats much cooler than necessary ... I've seen many of them set on the maximum cool setting, which typically targets a room temperature toward 60ðF.

Do you know the brand and model number of the condenser? If it is 8 years old it most likely has R22 refrigerant. It is going to take two people most of a day to reroute the lineset and electrical connection, reconnect everything and pull a vacuum. I agree the price seems high. It takes time to do it properly. You are better off in the long run spending a little extra money to do the move properly.

It is important to know whether you live in Miami or in Nashville. The southeast is a big place with different HVAC requirements. Air conditioners, by definition, are dehumidifiers. Cooling the air is a byproduct of dehumidification and vice versa. It sounds like you want a system that responds to both temperature and humidity. They make those but only at the top of the line units from any manufacturer. I had a Carrier Infinity system in my last house (San Antonio) and will get another one for this house when it needs replacing. These things are systems, not piece parts. You have to replace both units to make them work. Return air needs to be as big as it needs to be. If it's too small it will cause a whistling or rushing sound. If you cannot hear it at all, then it is close to being the right size. If you can hear it, then it is likely far too small. The result is the blower motor becomes more of a suction motor trying to suck air into itself rather than blowing air out. The inlet becomes a resistance valve instead of a flow and filter port. Doubling or tripling the return air should not be a problem for professionals. Have you entertained the idea of using a mini split heat pump system either in the main house or just in the basement. We put head units in our bedroom and bathroom and it's great. It's like having each room as its own zone. Mini splits don't have ducts, so you don't have to deal with return air sizing or cleaning out your ducts. They are ultra efficient with SEER values from 20 to the mid 30s depending on your situation. My outside unit is so quiet I have to look at it or stand in front of it to see if the fan is running.