I'd considering finding a way to design the house such that you can install DIY ductless mini-split systems. They can be very energy efficient, and installed D

I'd considering finding a way to design the house such that you can install DIY ductless mini-split systems. They can be very energy efficient, and installed DIY can be very inexpensive (relatively). Plus, if you're in a humid climate, you can find some that have de-humidification ability as an option.