Reddit reviews Bionaire 3 Speed/3 Fan Thin Window Fan

Sorry to hear that. I don't see how a tube out a window looks any better than a box. But an alternative would be two good window fans. When the sun is up, have both out takes to suck the warm air out. If it cools in the night turn one around for an intake.
I use these

I have a south facing condo in a poorly insulated building and it gets quite hot. I bought one of these window fans this year and it's been working really well. I put it in my bedroom window and it draws all the cool night air in. I find it very quiet, a low even hum, but I'm used to a fan running so YMMV.

I did buy mine from Amazon, but I've seen them locally in London Drugs and at Walmart.