Yeah, I only had one window cracked plus the one in the maids room (now storage and litter room) with the outblowing fan in it....... There's a reason the fan is on all the time and blowing out........Yesterday when the high hit 104 I went for a swim, it was just plane hot outside! Later in the evening after the sun went down I was out back, it was 91 degrees with a good stiff breeze..... felt wonderful.
Got home about a half hour ago, they could find nothing wrong with the AC in the Prius, stopped and got lunch then went by Albertsons. The house was warm even though the swamp coolers are running, opened the back slider and the house is cooling off very quickly.
That's the thing with a swamp cooler. We instinctively think if we close up the house, the cool air will stay inside, but it just doesn't work that way. You have to have enough ways for the unit to push the warm air out and replace it with cool for it to be 100% effective. Also if you don't let it push enough air out, the interior air gets more and more humid until you start having trouble with doors sticking and other evidence of high humidity.
My dad had a 1600 sqft house and only one swamp cooler, all one needed to do was crack 2 windows upstairs and one downstairs to turn that house into a walk in refrigerator........