I keep a HUGE kiddie pool in a shaded area all year round for them. On those hot and HUMID days; they spend a lot of time in their pool!
But other than that, they just chill in my garage during the day. My garage does not have ac like yours but it is a big two car garage that has 12 foot ceilings, and two huge windows (also, one of the garage doors is always open). Thus in the garage is cool and it has good ventilation.
During those extremely hot summer days, they spend a lot of time sleeping in the garage and ONLY come out to relieve them selves, cool off in the pool, or if a strange vehicle/person come to my house (which is rare).
But one thing that helped me in finally getting the breed was their ability to adapt. And in my opinion, they have adapted to our summers very well.