I am planning our nudura ICF home and have most everything planned out except for the hvac situation. I have the wood stove already and plenty of wood to harvest for years. I could go with a heat pump, but I'd like to find a better way to solve specifically the AC aspect of the hvac. I looked at the solar chill type systems but living in the south thats not a wise option. The humidity issue rules that out instantly. I had one guy suggest I look into the mini split heat pumps by mitsubishi and while I think they are great for small buildings, cabins and maybe a guest house, can these effectively cool a 2600 sq ft icf home? I don't doubt that they could do the job, but will it be a case of 1 room is freezing and the others are hot or what? I've looked at all sorts of options and the one thing that kills any plan is the 3-4 months where AC is an absolute must. If it wasn't for that, it would be easy. If I did use the mini splits, where would I put the vents and what about the fan portion of it. Would I want to combine that with the old whole house fans, or how would I incorporate the important ventilation aspect? It seems like the more I plan the more just an efficient heat pump is the best option from a cost and complication way to go. Thoughts?

If you are planning to use wood for your primary source of heating, then I suspect that high SEER rated heat pump will be your best avenue for cooling. The air handler portion of the heat pump can be used to move the wood fire heated air throughout the house. Work with your HVAC contractor to provide any special preparation that might be needed.
I suspect that we sometimes overthink the energy efficiency issue. A well built ICF home that is otherwise well sealed and insulated, will reduce the overall heating and cooling loads to a point where the introduction of more exotic equipment cannot possibly recoup the additional investment required over their usable life span. I become more and more convinced that the simpler solutions are best.

I agree with Wes.

It is very difficult to justify an expensive HVAC system when you have already paid for a super efficient ICF home.

Now after saying that, have you looked at Daikin AC?  This HVAC system can use multiple fan coils with one compressor.  It is an air system so no wells or trenches are needed.  This system can also reduce the amount of duct work.

thanks for the replies guys. While I think we will end up with a regular old heat pump, I will still look at the dankin ac unit. I just wonder if those units can hold up to years of use like a york, trane, carrier, etc, etc heat pump can?

So I looked at those daikan ac units, the multi room ones and I really liked what I saw. My only questions are:

1) Cost - Can't seem to find that anywhere and I hate to call and ask because I hate to deal with salesmen. lol
2) Fresh Air - I know they clean the air with a filter, but I was going to have a heat exchanger with whatever hvac unit we do have because of the tight icf house. But for about 6 months out of th eyear it is too hot or cold to have the windows open.

Thoughts?

I have a Daikin system. The local distributor told me that Daikin has been on the East Asian and European markets for around 20 years, the US market about 5 or 6 years. In the time they've been on the US market there has been only one compressor failure in all of US. The one failure was caused by the installer punching the refrigerant line through drywall subsequently leaving drywall residue in the line. The Daikin is Japanese and from everything I've seen they apply the best of Japanese quality methods to manufacturing them. My inclination would be to say if you have confidence in American brand systems (I have no hard evidence at hand to say you shouldn't) then you should be very comfortable placing confidence in the Daikin systems. Probably Mitsubishi also.

1) I don't think you have any other choice, really. I don't know if it is true where you live, but I would be inclined to think it would be, Daikin will not take on just any HVAC contractor as a dealer. The dealer has to have a proven track record of good performance in design, installation, and maintenance support. There are boo coo lots of HVAC contractors around the Boise, ID area who handle the brands you list. There are only two I know of who have been taken on by Daikin.

Don't ask, but let the HVAC contractor you talk to take the initiative. If the first thing he starts talking about is how good a price he can offer for such and such a system and this is probably what you need for size, dump him like a hot rock. On the other hand, if the first thing he says is he needs to come and look at your house, or he needs to look at your house plans, so he can do a proper heating and cooling load calculation in order to recommend the proper size and configuration of HVAC system, talk to him. He won't be the cheapest, but he most likely will be the most honest.

2) I presume you're referring to an HRV or ERV, right? As you probably have seen in these forums controlled air exchange is preached over and over again. Whether it should be a simple exhaust/intake pair of fans, or a full blown energy recovery unit, or in between, is a subject of debate. Your particular situation will dictate the best way to go. That system can be integrated into your HVAC system, or installed seperately as a stand alone system. What works best for you is the way to go. A reputable HVAC contractor can advise on this.

We used the high speed duct system, I can't recall the particular name for it , but it utilizes 2" ducts from a central unit so the runs can be done just about anywhere. Worked reallly great for a addition we did and it is energy efficient. We did a four year energy audit before the addition and with addiing 660 more SF to a 1200 SF ranch style home our extra energy cost were $ .23 cents a day to feed this area over what was paid out before the addition. This was a excellent way to give us our AC.

Thanks for the reply. I had taken a look at those but for some reason they are more expensive than anything else I looked at. I think because they are not as common that translates into they need to cost more which makes no sense. lol What brand did you use? Maybe I'll take another look.

www.unicosystem.com

I have a High-Velocity system in my own house, and used it for clients' ICF homes.

The system is a simple insulated duct with thye 2" feeds for the rooms, and a central return air port. Sometimes these units can be expensive, but then again its who you deal with, in general.

If you can get one of the newer 2 speed units, I think you'll be happier; mine is a single speed. Only used for cooling, I abandoned the hot water coil heating side.

In your case, you could always retrofit the unit with a backup electric heating coil, for when the wood can't keep up, or when someone is gone, and you need the house to maintain above freezing temps.

Let me just reemphasize the importance of air exchange, especially if you plan to do the majority of your heating with wood. Living in a super-insulated house is the best way to go, but raises your risk of carbon monoxide poisoning from any combustion-based source. Please make sure you have a plan to exchange air, especially when the woodstove is in use.
I suffered carbon monoxide poisoning from a faulty propane furnace in my home last winter, and the fact that I currently live in a drafty old log cabin probably saved my life. I am still recovering from this, and it is definitely not something you want for yourself or your family.
If you can, use a woodstove that draws intake air from outside, rather than pulling from inside your living space.
Good luck!