I am currently in the market to buy a 4000 square feet home which was built with ICF. Needless to say, the seller's broker only knows "buzzwords" about ICF ... understandably so since this is all new to me too but I have been doing some research into ICF myself and have been trying to become a bit more educated on the topic. My question is this: This home currently has a hydronic radiant heat system for the winter so there is no "vent" system in place. For the summer, I was told by the seller's broker that "There's no A/C because the insulation is so good that you don't need it." There are ceiling fans installed in every room in the house as of now. The home is located in New Hampshire which can have devastating cold winters and occasionally warm/hot summers and from my understanding, some humid days/nights as well.

My question is this:
1. Do you think it would be necessary to have central air in an ICF-constructed home (I understand that this answer would vary probably according to geographic location)  Does it make sense that it would provided enough "coolness" purely by the nature of the level of insulation? Is it, in general, necessary to have some sort of air filtration system in place for general air circulation purposes?

2. If there is no central air, is this still possible to install in spite of ICF construction? Does it make the process all that much more difficult and do you need a contractor/installer especially skilled with ICF in order to install it?

3. Finally, if one were to install central air, what do you think we're looking at in terms of potential costs (i.e. the size of the unit to heat a home built with ICF)

Thanks in advance for your response. -JH

One story or two? That would make a huge difference. The vents would have to go in the ceiling....as far as I know.

added......crawl space or slab? Big dif. here also.

As to your need for air condiitioning, there are too many variables to any of us to give an informed answer. Most of the variables are geographic in nature, but also the style and shape of the house will also play a major role in this.
An a/c system can be installed in almost any home. The design of the home will determine how difficult and expensive the process will be.
You may just have to live in the house for a summer to determine whether you really need to install a/c. Also, you might consider an old fashioned window unit. If your cooling load is as small as broker says, the window unit might be all thats needed.

It is not the temperature you need to control, it is the humidity. Anything over 50% humidity can cause problems. The solution is not a simple answer, it depends on a lot of factors. Such as your local climate, how the rest of the house is insulated, leakage from windows and doors and how warm or cold you want the house to be.

Best bet is to talk to a trusted professional (or maybe a few) familiar with this type of house in your area. They may be able to give some insight as to what to do.

Clavicle,
If you are comfortable using technical software, I suggest you check out the HEED: Home Energy Efficient Design program from UCLA. It's at http://mackintosh.aud.ucla.edu/heed/. One of its outputs is an hourly chart of the temperature swings in a house.

Another factor is your lifestyle and heat tolerance.  My wife is allergic to almost anything that grows or has hair, so we keep our windows closed and rely heavily on AC and filtration.

Others may be happy to leave their windows open all the time or to cool the house at night.  That does not work for us.

If it is a good, tight ICF house it should have a HRV to provide fresh air and to remove humidity.  If you can eliminate solar gain with shading, you will greatly minimize your heat load.

To add airconditioning to a house with no duct system, a ductless "mini split" may be the easiest solution.  This uses a wall mounted unit in each of the rooms you want to cool.  One outdoor unit will likely be sufficient.  Most of them also have a "dehumidify" setting which is handy.  Condensate drainage is needed from the interior units.  The condensate piping is sometimes more of a routing problem than the supply piping.

We live in Europe and we have minisplits in our bedrooms and living room only....very nice and very quiet.  Europeans typically tolerate higher or lower temperatures than Americans and many cling to the belief that AC is not healthy (I don't think the noise, dirt and mosquitos are healthy).  I enjoy coming to work in the summer after a good night's sleep while my colleagues without AC come to the office looking a bit bleary and grumpy.  There is a reason the Europe largely closes in August.

The advice to "try it and see" is sound.

Bruce

No matter what icf homes need an hrv, air conditiong isn't a bad idea either. In summer months the ambient air at some point will be same as outside air what then? The a/c will also adress the humidity for a more comfortable living. The humidity is what I'm worried about.
Cheers!