John Harlow a écrit :
What would be the problem with ducting cool air from under a house to the
attic in warmer months to help with cooling, and just the opposite in the
winter to help with heating?




Depends what "under a house" means. Is the house elevated? Is the house
on a concrete foundation? etc etc..

Do you mean taking cool air from an existing cavity or laying a couple
of pipes under the house and getting air from there? If its the second,
it's reasonably common (it's called a Canadian Well here in France). If
it's the first, it would depend on the air temperature, the thermal
mass's capacity and fan running costs (cold air won't rise on its own...)


Mel