I have a 100 year old, 2000 sq. ft house in new orleans that is about 4 feet off the ground. The floor is in excellent condition, but it's the hardwood and that's it. No subfloor, so winter is chilly. I got an estimate of $3300 for closed cell foam. But, considering that our winters are pretty short and mild, I want the investment to help with cooling costs as well. I have uninsulated walls and cellulose in the attic.

If anyone has an experience adding crawl space insulation, I'd love to hear what impact it has on your cooling costs. Everything I hear/see/read points to saving on heating costs, not cooling.

Many thanks in advance for your thoughts.

below is a copy & paste link to LSU AgCenter's study
about insulating floors in homes with open crawlspaces.

http://www.lsuagcenter.com/NR/rdonlyres/D33F711D-DC4B-4E4C-9ED6-A97DCE 9DB026/79806/pub3187insulatingraisedfloorsHIGHRES.pdf

I plan to insulate my floors with closed cell
3" everywhere...not average fill.
once floor in bathroom is replaced and
plumbing is finished.
your biggest battle is going to be getting
3" everywhere, and not just averaged fill.
plan to crawl under house before they
leave. take a piece of wire with inches marked
on it and a can of spray paint.
have them come back and touch up low spots.

knowing the foam companies you'll have to
deal with, plan on double checking the work
and not relying on their word that it is right.

understand that closed cell is about R-7 per inch
so 3" is R-21. actual R-values not quanitive values
are what is important.

best of luck.